Abstract: Population growth, urbanization and global climate change have increased urban and agricultural water demands, stressing aquifer systems where groundwater is a source of water supply. The availability and utility of groundwater may further be threatened by factors stressing the quality of groundwater, such as industrial and domestic wastes and agricultural intensification. To address this issue, a symposium was organised by the IAHS International Commission on Groundwater (ICGW), supported by the International Associaton of Hydrologists (IAH) and by the IAHS International Commission on Water Quality (ICWQ), in Hyderabad, India, September 2009.
Abstract: Water and chemical fluxes across the sea floor provide an important linkage between terrestrial and marine environÂments. Oceanographers recognize that these fluxes may act as a source of nutrients or harmful contaminants to marine systems. They may also act as a beneficial source of freshÂwater for coastal estuaries that require relatively low salinities. Hydrologists and hydroÂgeologists recognize that fluxes across the sea floor comprise an important part of the water balance for coastal aquifers. Most fresh groundwater discharge to the ocean is derived from terrestrial aquifer recharge. However, excessive groundwater withdrawals from coastal aquifers can cause saltwater intrusion by interÂcepting the seaward flux. Quantitative estimates of fresh groundwater discharge toward the coast can provide a basis for determining safe withdrawal rates. Oceanographers, marine scientists, and those studyÂing and managing saltwater intrusion in coastal aquifers, share a common goal of quantification and underÂstandÂing of groundwater and seawater interactions. The papers in this volume, an outcome of a symposium organised jointly by the IAHS International Commission on GroundÂwater and the International Association for the Physical Sciences of the Oceans, IAPSO, in 2007, present research by those working from the marine and terrestrial sides of the issues, and cover a variety of investigative approaches applied at locations worldwide. Together, they form an important contribution to the literature.
Abstract: This guideline focuses on development of a âgeneral reference monitoring programmeâ for the early stage of groundwater reconnaissance, groundwater development and groundwater management. The objectives of the monitoring programme are to supply data for characterisation of the regional groundwater systems, identification of trends in time and prediction of the regional impacts of groundwater abstraction. Technical as well as institutional and budgetary aspects will be discussed.
Abstract: In this paper, we present a methodological approach based on a comparative analysis of floods that occurred in a wide region over a long period and the climatic data characterising the same period, focusing on the climate trend. The method simplifies the comparative analysis of several time series by defining some indexes (e.g., the monthly, bi-monthly, and ⦠m-monthly indexes of precipitation, temperature, wet days and precipitation intensity and the monthly flood number) that can be used to study phenomena such as floods that are characterised by spatial and temporal variability. The analysis was used to investigate the potential effect of climate variation on the damaging floods trend.
The approach was tested for the region of Calabria (Italy) using historical flood and climatic data from 1880 to 2007. The results showed that the number of floods was correlated with the monthly indexes of precipitation, wet days, and daily precipitation intensity. The following trends were recognised: decreasing precipitation and wet days, almost constant precipitation intensity, increasing temperature, and linearly increasing floods. A second-order polynomial trend analysis showed a slight decrease in floods since the seventies, which might be explained by the favourable climatic conditions during the period and/or the effect of increasing awareness of flood vulnerability.
Abstract: The risk of failure of transportation embankments due to seepage induced by temporary and occasional impoundments taking place on the upstream side as a consequence of exceptional rainfalls is frequently underestimated. These failure events result from a combination of three main factors, i.e. the flooding event, the hydraulic weakness and the geotechnical weakness of the embankment. Based on the case study of a railway embankment in Southern Italy that collapsed in 2005 due to an upstream impoundment that occurred after few hours of a very intense rainfall, the paper describes a methodological approach aimed at assessing hazard of failure of transportation embankments induced by flooding and seepage. In particular, ccording to hydrological, hydraulic and geotechnical studies performed to define the factors affecting the process of the embankment failure, three subsequent activities are proposed: the historical analysis of flood damages at the watershed scale; and the assessment of the upstream peak impoundment based on hydrological analysis and the embankment stability analysis, these latter to be carried out at the site specific scale. The approach here proposed is planned to be further validated and improved by means of the application to other case studies, characterised by different contexts and embankment structures.
Abstract: The study discusses the large karstic coastal aquifer of Vlora Bay. This case is peculiar, as the submarine groundwater discharge has a relevant rate of terrestrial inflow in an almost closed bay that is located in an environmentally valuable area.
The study is based on four methodological activities: geological and hydrogeological conceptualisation, climatic study and hydrological balance, numerical modelling, and monitoring.
A geodatabase was created considering hundreds of data points (wells, springs, rivers, lagoons, and seas) and monthly time series of rainfall, temperature, and river discharge.
Monitoring activity was realised over a hydrological year, installing a rainfall network tool and using a network of tens of sampling points, including springs, wells, lagoons and sea. Chemical-physical and stable isotope determinations were realised.
Two main groups of aerial springs are fed by the aquifer, one of which is of a coastal type. The total spring discharge is roughly 4 m3/s. The GSD was assessed as being equal to 1.4 m3/s on the basis of the current rate of anthropic discharge and climatic conditions. The study showed the peculiarities of this carbonate coastal aquifer and the importance of its groundwater, which is the chief water source for the third-largest Albanian town.
The groundwater quality was generally high, mainly due to the negligible presence of contamination sources on the relief in which the aquifer outcrops. The rate of seawater intrusion effects was also low, thanks to favourable aquifer 3-D geometry and high recharge levels.
The increasing anthropic activities constitute a relevant risk in the absence of the introduction of rigorous land and water management criteria.
Abstract: A methodological approach based on analysing landslides that occurred over a long period and climatic data characterizing that period is presented. The method investigates whether there are any effects of climate on landslide triggering. The approach has been tested in Calabria (Italy). Both landslide and climatic data have been obtained from available databases that have been expanded. Landslide data came from historical archives and newspapers, whereas the climatic analysis is based on daily and monthly series of rainfall and temperature. The method simplifies the comparative analysis of several time series by defining some indices (the monthly, bi-monthly ... m-monthly indices of precipitation, temperature, wet days and precipitation, and the monthly landslide number) that can be used to study phenomena, such as landslides, that are characterized by spatial and temporal variability. For Calabria, the number of landslides is correlated to monthly precipitation, wet days and precipitation intensity. Thus, landslide occurrence could be roughly forecast using these climatic data. Despite the favourable climatic trend, landslides are not decreasing because the recent utilization of landslide-prone areas increases the vulnerability.
Abstract: In karstic areas, the mean annual stream flow is low in terms of mean annual net rainfall percentage, and, in many cases, stream flow is so rare to be considered an exceptional independent of the peak flow value. Nevertheless, many types of flooding processes can be identified in karsts. We consider the recharge-related flooding of a bare karst, with a case study of a Mediterranean area dominated by semi-arid climate. In these cases floods are rare, short, and sudden but the effects are often very dramatic. Three types of analyses were used. The historical analysis focused on the series of past or historical flood events, which provided a means to define the flood recurrence period and damage levels, and the main steps of anthropogenic development expressed by the population number and needs. The hydrological analysis considered long time series of annual maximum short rainfalls, in order to assess the return period of high intensity rainfall that caused the studied flood event. The geomorphological analysis considered rainfall, the hydrogeological characteristics of outcropping rocks and soils and the geomorphological data of the drainage basin to calculate net rainfall and peak flow characteristics. We explored historical flood events for the study area, characterising the role of human effects on damages, and used a recent flood event to test our capability to estimate ephemeral river flow on the basis of rainfall measurements. The historical analysis of floods and damages highlighted four flood periods, distinguished on the basis of the recurrence period and the level of damages. It is clear that the lessons of past flood events are quickly forgotten.
The hydro-geomorphological analyses showed the peculiarities of the 2005 flood event. The maximum rainfall return period for the 2005 event was due to exceptional three-hour cumulative rainfall. This study shows that we can estimate peak flow characteristics even when time series of river flows are not available, thereby allowing us to improve our capability to forecast the flooding effects of severe storms in karstic areas.
Abstract: The availability of good quality water is worldwide a basic condition to pursue the socioeconomic development. The agriculture water demand can be damaged by contamination of groundwater resources. This paper proposes a tool to preserve the groundwater quality by using groundwater vulnerability assessment methods and a decision support system (DSS). Vulnerability map could be used for planning, policy, management, and contamination assessment. The mapping of intrinsic groundwater vulnerability was based on reliable methods, i.e., the DRASTIC and the SINTACS methods. A vulnerability map could be used for planning, policy, management, and contamination assessment. A DSS was developed in order to assess the groundwater vulnerability and pollution risk due to agricultural activities and land use changes. The proposed DSS software package was designed using the Matlab language. The software is a friendly application for everyone ranging from the novice user, e.g., a student, to an operations research scientist. It quickly and efficiently performs the task that is scheduled to carry out, and it can incorporate new maps in order to cover new areas. The tool was tested using two study areas located in the Mediterranean area. The test sites are dominated by different prevalent hydrogeological features, i.e., the typical porous features of alluvial deposits in the Greek study area and the typical fissured and karstic features of limestones and dolostones in the Italian study area.
Abstract: Approximately 70% of the population of the earth lives in coastal areas and the majority of these people depend on coastal aquifers for freshwater. For this reason the coastal aquifers are vulnerable to pollution and are now recognized as a crucial arena for future progress towards sustainability in world. This paper deals with the assessment of groundwater vulnerability of Kiti aquifer, South Cyprus. The Kiti aquifer, covering an area of about of 30 Km2, is situated in the southern part of Cyprus with a mean elevation of 20 m above sea level. The area is characterized by semi-arid climatic conditions. The groundwater resources are related to the Pleistocene coastal plain and the recent Tremithos river valley deposits. The concept of the groundwater vulnerability is based on the assumption that the physical environment may provide some degree of protection to groundwater against human activities. The DRASTIC method is applied to evaluate aquifer vulnerability. The method was developed by the United State Environmental Protection Agency (EPA), as a technique for assessing groundwater pollution potential, and is based on seven (7) parameters: Depth (D), Recharge (R), Aquifer media (A), Soil media (S), Topography (T), Impact of the vadose zone media (I), hydraulic Conductivity of the aquifer (C). Determination of the DRASTIC index (DI) involves multiplying each parameter weight by its site rating and summing the total. Based on DI values a groundwater vulnerability map was illustrated, using a Geographical Information System (GIS). The highest vulnerability values in the Kiti area, covering a large part, are associated with shallow aquifers without great depth of the vadose zone. The results provide important information and the vulnerability map could be used from local authorities and decision makers who are responsible for groundwater resources management and protection zoning.
Abstract: Damaging Hydro-geologic Events (DHEs), de- fined as landslides and floods caused by heavy or prolonged rainfall, represent an important source of economic damages. We propose an approach to classify DHEs, considering 1) meteorological antecedent conditions, 2) the season during which the event occurs, 3) the return period of maximum daily rainfall triggering the event, 4) geographic sectors hit, 5) types of triggered damaging phenomena; and 6) induced damage. We applied this approach to a case study of time series of DHEs that occurred over 85 years in Calabria (southern Italy). We analysed 13 DHEs that, between 1921 and 2005, triggered landslides, floods and secondary floods, causing severe damage and tens of causalities all over the Calabria region. During the analysed events, 64% of Calabriaâs municipalities suffered many types of damage. The most relevant rain phenomena and the largest damages were caused by the persistent effects of perturbations on Calabria, which were preceded by the appearance of low-pressure fields in two different areas located westwards. We sorted the events into three types based on geographic damage distribution and types of triggered phenomena and induced damage. The first two types are characterised by similar severity levels, while the third shows the highest severity, in terms of both damage and victims. Independent of the type of event, the S-SE and E sectors of the region are the most frequently affected by DHEs. As regards human life, floods are the most dangerous type of phenomenon, causing the highest number of fatalities. Our analysis indicates a decreasing frequency of DHEs during the study period, and an absence of the most severe type for more than 50 years. The number of victims is also decreasing over time.
Abstract: A period of bad weather conditions due to prolonged intense rainfall and strong winds can trigger landslides, floods, secondary floods (accumulation of rain on surfaces with low permeability), and sea storms, causing damage to humans and infrastructure. As a whole, these periods of bad weather and triggered phenomena can be defined as damaging hydrogeological events (DHEs). We define a methodological approach based on seven simple indexes to analyze such events. The indexes describe the return period (T) and trend of rainfall, the extent of hit areas, and the level of damages; they can be considered attributes of georeferenced features and analyzed with GIS techniques. We tested our method in an Italian region frequently hit by DHEs. In a period of 10 years, 747 damaging phenomena (landslides, 43%; floods, 38%) and 94 DHEs have been classified. The road network and xD;housing areas are the most frequently damaged elements, threatened by all types of damaging phenomena. T classes are almost in accordance with the level of damage. These xD;results can be used to outline warning levels for civil protection purposes, to forecast the areas most likely to be hit and the potential ensuing damage, to disseminate xD;information concerning vulnerable areas, and to increase peopleâs awareness of risk.
Abstract: Karstic aquifers are well known for their vulnerability to groundwater contamination. This is due to characteristics such as thin soils and point recharge in dolines, shafts, and swallow holes. In karstic areas, groundwater is often the only freshwater source. This is the case of the Apulia region (south-eastern Italy), where a large and deep carbonate aquifer, affected by karstic and fracturing phenomena, is located. Several methods (GOD, DRASTIC, SINTACS, EPIK, PI, and COP) for the assessment of the intrinsic vulnerability (Iv) were selected and applied to an Apulian test site, for which a complete data set was set up. The intrinsic vulnerability maps, produced using a GIS approach, show vulnerability from low to very high. The maximum vulnerability is always due to karstic features. A comparison approach of the maps is proposed. The advantages and disadvantages of each method are discussed. In general terms, three groups can be distinguished. The GOD method is useful for mapping large areas with high vulnerability contrasts. DRASTIC and SINTACS are âanytype aquiferâ methods that have some limitations in applications to karstic aquifers, especially in the case of DRASTIC. EPIK, PI, and COP, which were designed to be applied to carbonate or karstic aquifers, supply affordable results, highly coherent with karstic and hydrogeological features, and reliable procedures, especially in the case of PI and COP. The latter appears simpler to apply and more flexible in considering the role of climatic parameters. If Iv of each method is considered, the highest variability is observed in cells in the neighbourhood of karstic features. In these spatial domains, additional efforts to define more reliable and global methods are required.
Abstract: A multi-methodological approach based on monitoring and spatio-temporal analysis of groundwater quality changes is proposed. The presented tools are simple, quick and cost-effective to give service to all sorts of users. The chief purpose of the monitoring network is the detection of the piezometric or potenziometric level in the aquifer. The spatial and multi-temporal analysis of usual chemical and physical data provides both an assessment of the spatial vulnerability of the aquifer to seawater intrusion, defining a salinity threshold between fresh groundwater and brackish groundwater and of the water quality trend in terms of salinity. The evaluation of the salinity trend or of salinity-correlated parameters highlights the effects of groundwater mismanagement. The multiparameter logging provides a rapid groundwater quality classification for each well. The whole approach allows evaluating the effects of current management criteria and designing more appropriate management targets. The Apulian karstic coastal aquifers have been selected as a case study (Southern Italy). Three types of aquifer zones can be distinguished: (1) areas with low vulnerability to seawater intrusion, (2) areas with high vulnerability and (3) areas with variable vulnerability in which the salt degradation largely depends on the ability to manage the well discharge. The water quality degradation caused by seawater intrusion appears to be a combined effect of an anomalous succession of drought periods observed from about 1980 onwards and increased groundwater pumping, particularly during drought periods. A management criterion based on aquifer zones is proposed.
Abstract: A study of the effects of human modification of a coastal plain mainly involving land reclamation and flood protection is proposed. The approach involves historical, geomorphological and hydrological data as a whole, taking into account the equilibrium of rivers, plains and coastal areas. The test area, a telling example of profound economic and social transformation of a coastal plain, is the Piana di Sibari (Calabria, southern Italy), subject to major human modifi- cations over the last 150 years. The study area, at most 300ma.s.l., is 450 km2 wide and comprises 24 hydrographic basins. The approach is based on the creation and analysis of four databases: 1) a historical series of geo-coded flood damage (DAMAGES database), concerning damaging floods which occurred over the past few centuries in the study area; 2) a geocoded series of protection works for land reclamation, protection from floods and improvement of soil stability in steep areas (WORKS database), gathered from the archives of the agencies that carried out the works, organized in a GISformat; 3) a historical series of maximum flood discharges and extreme rainy events (HYMAX database) aimed at defining the trends of occurrence and the intensity of flooding; 4) a coastal line position and migration over time (COASTAL database), created using mainly literature data based on discontinuous data such as historical maps and images. The work describes the complex succession of floods, protection and reclamation works, human transformation of the plain and major land use changes over the last two centuries in the test area. The new characteristics of the plain and its modifications, including major engineering works, land-use transformation and urbanisation, are illustrated. The damaging floods of the last 200 years, the modifications of runoff and flooding due to works built over the basins, hydrological data and the records concerning coastal modifications were Correspondence to: O. Petrucci (o.petrucci@irpi.cnr.it) used to create specific databases and a GIS in which these data can be analyzed by typology, location and extension. The proposed approach highlights the high degree of correlation between drainage basin management, mainly in terms of increasing protection from natural hazards, and anthropogenic development in a broad coastal plain.
Abstract: During the last century the land reclamation works, the built-up of dams and modern irrigation systems, the farm and industrial activities, and the overexploitation of the wells, associated to several periods of drought, have deeply modified the quantity and the chemical state of the groundwater resources of the Metaponto coastal plain (Southern xD;Italy). The degradation of the groundwater systems seems to be increased with the time as shown by the piezometric trends (1927-1990) and by the chemical-physical data (1990-2003). The chemical-physical state of the groundwater has been defined according to the hydrochemical classification proposed by an Italian legislative decree.
Abstract: The Apulian region is characterized by very low availability of surface water resources due to its karstic nature. Considerable groundwater resources are located in large and deep carbonate coastal aquifers. Groundwater is affected by two types of degradation risks: quality and quantity degradation. The withdrawn of groundwater resources produce a xD;massive degradation, along the coastal aquifers, for increasing salt contamination due to sea water intrusion. At the same time, various anthropogenic polluting sources have contributed to the qualitative degradation of the resource, also in the inner areas. To the aim to evidence the evolution in action of the groundwater resources quality degradation risks, are discussed data that it have been collected from numerous surveys that have interested coastal spring and wells in the entire region. In particular, the cognitive state is reported to the systematic surveying carried out from 1995 to 2003. In such survey the piezometric levels, the specific electrical conductivity, the pH, the Eh and the concentrations of main ions together with nitrogenous species have been determined for more than 100 wells. In adding, has been analyzed the waters of some coastal spring, selected between the more important of region, because the quality of coastal spring assumes great importance for the remarkable effects hydrological and ecological equilibriums of coastal and lakes environments. The enforced Italian law (D.L. 152/1999 e D.L. 258/2000) has been used as a comparative reference, defining a synthetic picture of the qualitative state of groundwater of the Apulia Region. It is found that the pollution of groundwater is absent in narrow inner areas, placed in the recharge areas of the aquifers. From such areas the groundwater flows towards the sea, along the way acquiring a polluting load coming from ground surface. Such pollutants are discharged into the sea or into lagoons, creating ecological risks also for coastal areas of particular interest.
Abstract: The results of the geochemical investigation of 54 springs flowing into the drainage basins of the river Abatemarco and of the stream Vaccuta (northern Calabnia) are reported in this paper. Considerations on the chemical composition of the waters, hydrogeological information and six thematic maps were made allowing to identify three main aquifers: a deep aquifer in equilibrium with carbonate rocks, a superficial metamorphic aquifer and a valley aquifer constituted by conglomerates and sands. The presence of sulphate waters, not related to the surface geological setting and their alignment along preferential lines, indicates the ascent of deep fluids derived by the dissolution of evaporite layers.
Abstract: The predisposing factors and the determining factors of seawater intrusion in wide carbonate aquifers of Apulia ( Southern Italy) are characterized. Main predisposing factors prove the sedimentation environment, the tectonic-karstic evolution, the geometry of the aquifers in relation to the coastline, the depth of the aquifers, the existence of underground outflows and their chemical nature. The effect of salinity pollution and its trend was characterized using data from a regional monitoring network, considering logs time series, and also from well loggings. The intensive and widespread use has led to a progressive deterioration in water quality, particularly in the Salento area, right where the aquifer is most susceptible to seawater intrusion.
Abstract: Lo studio considera precipitazioni e temperature mensili in Italia meridionale tra il 1821 ed il 2001 utilizzando 126 stazioni del SIMN. Si individuano i trend termopluviometrici e si caratterizzano i periodi di maggiore siccità . Nel periodo 1921-2001 si osservano cali pluviometrici tendenziali in 114 stazioni. La tendenza negativa riguarda più del 95% dellâarea, ed è più evidente dove è maggiore la piovosità assoluta. In particolare, si risente di un consistente deficit di precipitazioni registratosi a partire dal 1980. Le medie mobili pluriennali evidenziano minimi storici nei periodi 1989-91 e 1999-2001. La media delle precipitazioni del 1981-2001 è significativamente minore dalla media 1921-1980. La tendenza negativa interessa soprattutto la stagione invernale. Lâanalisi dei dati di temperatura evidenzia la tendenza ad un lieve incremento termico negli ultimi decenni, che causa unâulteriore riduzione tendenziale delle piogge efficaci.
Abstract: Landslides, floods and secondary floods (hereinafter called phenomena) triggered by rainfall and causing extensive damage are reviewed in this paper. Damaging Hydrogeological Events (DHEs) are defined as the occurrence of one or more simultaneous aforementioned phenomena. A method for the characterisation of DHEs based upon xD;historic data is proposed. The method is aimed at assessing DHE-related hazard in terms of recurrence, severity, damage, and extent of the affected area. Using GIS, the DHEs historical and climatic data collection, the geomorphological and hydrogeological characterisation of the hit areas, the characterisation of induced damage, the evaluation of triggering rainfall return period and critical duration of each DHE were carried out. The approach was applied to a test site in Southern Italy (Calabria) for validation purposes. A database was set up including data from 24 events which have occurred during an 80-year period. The spatial distribution of phenomena was analysed together with the return period of cumulative rainfall. The trend of the occurred phenomena was also compared with the climatic trend. Four main types of Damaging Hydrogeological Events were identified in the study area.
Abstract: The considered study area is, subjected to a semiarid climate, lying in Southern Italy. Data coming from 1130 boreholes have been considered to define the geological and hydrogeological set-up of the study area and for estimating the groundwater use and the salt-related groundwater quality degradation. The aquifers are constituted by marine terraces deposits, river valley alluvial deposits and alluvial and coastal deposits. Groundwater flow is mainly unconfined in the marine terraces and in the river valleys while it becomes mostly confined in the coastal plain aquifer. Being the direct natural recharge extremely low, the recharge of this coastal aquifer is mainly guaranteed by the discharge from upward aquifers and from the river leakage. Two dominant types of groundwater have been distinguished: the HCO3-Ca type (in the marine terraces and in the alluvial deposits) and SO4-Cl-Na type (in the coastal plain deposits). The variability of major ions contents is related to many factors such as the different lithologies of the aquifers, the seawater intrusion, the mixing with river water and the impact of intensive farming. As regards the presence of the seawater intrusion in the study area, the analysis of the concentration maps of TDS, groundwater electrical conductivity and of the ions present in seawater, generally indicate that seawater contamination is relevant along a strip of land stretching for 2.5-3 km from the coastline inwards. The new acquired knowledge permits to delineate scenarios useful for an optimization of the groundwater resources tapping and for pursuing the safeguard of them.
Abstract: The study area falls within the lonian coastal plain (Southern Italy), bounded on the West by the Sinni River and on the East by Bradano River. It covers 40 km along the coast and 6 km inland. The geological and hydro geological features of the study area and the chemical-physical groundwater characterisation have been inferred from the data analysis of 1130 boreholes. Some aquifers, connected among them, constituted by soils of different geological origin, exist in the area also if the coastal plain aquifer is the most interesting for practical utilisation. Groundwater flow is mainly uncon fined inland, where the aquifer is constituted by terraced deposits and confined in the alluvial coastal plain. xD;An upper clayey layer overlies the sandy coastal aquifer characterised by a mean hydraulic conductivity value equal to 2.3 10 rn/s. Being the direct natural recharge extremely low, the recharge of this coastal aquifer is mainly guaranteed by the discharge from upward aquifers and from the river leakage. xD;The bottom of the aquifer is a siliy-clayey bed which lies under the sea level permitting so the seawater intrusion. This phenomenon involves the studied coastal plain fora width of]-1.5 km on average and it is less evident moving inwards where the altitude of the clayey bottom of the aquifer becomes progressively higher than the sea level. Other chemical-physical data, studied to determine the quality of the waters, showed that the pollution of the groundwater is considered a grave environmental problem for the studied area.
Abstract: Si descrivono le metodologie utilizzate e i risultati conseguiti con uno studio di dettaglio di unâarea campione dellâunità idrogeologica del Salento (Puglia), costituita da un vasto acquifero carbonatico mesozoico. xD;Tale area, rappresentativa sia degli aspetti idrogeologici tipici delle zone di alimentazione del Salento sia degli effetti dellantropizzazione, è sede di nurnerosi pozzi adibiti ad uso potabile. xD;Lo studio è stato finalizzato alla redazione della carta della vulnerabilità dellâacquifero con ii metodo SINTACS. La natura sperimentale dellâapplicazione è legata alle peculiarità dellâacquifero salentino e allâassenza di esperienze pregresse per tale contesto. xD;Sono stati effettuati rilievi diretti, prove idrogeologiche e piü cicli di campionarnento idrico ed analisi di laboratorio. xD;I centri di pericolo sono stati censiti sulla base delle banche dati disponibili ed ispezionando ii territorio. Lâinfiltrazione si è dirnostrata molto rapida, anche laddove lâacquifero non affiora. xD;La vulnerabilità è risultata notevole, da alta a molto elevata. La qualita delle acque, per quanto tuttora buona, si è dimostrata sensibile alla posizione e allâazione dei centri di pericolo. I rischi di degrado qualitativo sono risultati non trascurabili.
Abstract: The Vadoncello landslide was mobilized in December 1993 and is still active. It involves highly tectonized soils and is the reactivation of a landslide dragged by a larger landslide at the toe of the slope soon after the 1980 Irpinia (Southern Italy) earthquake. Investigations and monitoring of the Vadoncello landslide were carried out, between 1994 and 1996, within an EC funded research project. The slope has been found to be formed of chaotic successions of soil and rock strata which have been grouped into soil complexes. The soil mechanical properties are shown to be very poor, the deep soils being prone to large plastic straining even due to relatively small loading changes. The soil displacements show that a shallow fast rotational sliding has occurred at the top of the slope and a shallow earthflow has developed downslope, both lying above deeper soils involved in a mechanism of slow and long-lasting irrecoverable movements. These slow deep movements are considered to be consequent to the plastic flow of the clayey soils. They can be activated by the effects of seasonal rainfall, of low-medium intensity seismic events and by the effects of the morphological changes resulting from the slow movements themselves. The landslide reactivation in 1993 is seen to have been the combination effect of a low return-period rainfall event and the slow movements active at depth in the slope.
Abstract: This paper describes a methodological example of a data-integration procedure to improve the knowledge of landslide hazard related to a seismic area in the southern Apennine (Italy). Attention is focused on remote sensing data. The analysis is validated using detailed topographical, geophysical, geotechnical and hydrogeological data as ground truth. The investigated phenomenon, which started at the end of 1993, is an earthflow. The presented methodology recommends the combined use of DEM, multi-temporal panchromatic visible aerial photographs and thermal infrared images. The integration between these data and multidisciplinary monitoring data proved useful. The main hydrogeological pattern, the geological and geomorphological framework and the areas of latent instability can be clearly determined. Insight can be gained through the synoptic slope view in the relative short time needed to cany out the analysis. The proposed approach can be regarded as a useful contribution to the evaluation of landslide hazard, particularly during emergency periods. 0 2001 Elsevier Science Ltd. All rights reserved the 1980 earthquake. Interdisciplinary investigations and monitoring âwere carried out between 1994 and 1996, within an EC funded research project (EC, 1996) and partially continued by Authors. This area has been chosen as a case study owing both to the landslide dimensions, which are large enough to allow remote sensing, and the wealth of available data. The selection of the most suitable kind of data - mainly remotely sensed - and the proposal of the most appropriate processing is aimed at improving landslide knowledge. The availability of field data ensures the validation of the proposed work. The combined analysis of DEM, panchromatic visible aerial photographs and thermal infrared images has been carried out aiming to perform a study approach able to provide a multi-temporal and multi-spectral analysis of slope instability phenomena. This framework has then been merged to data coming from multidisciplinary monitoring of study area in order to both verify the results of image analysis and test the proposed methodology
Abstract: In order to assess the evolution of seawater intrusion and the resulting saline Contamination, the trends of the 0,5 g/l isohatine over three time lags (1981, 1989. and 1997) were compared, since, at First approximation, water whose salinity is equal or lower than the above value is salt contamination free. In large areas along the Adriatic and lonian shoreline groundwater saline contamination is resulted to be a long-standing phenomenon. Only the Murgia interior and a restricted strip in the middle of the salentine peninsula have not been contaminated so far. From 1981 to 1989, the reference isohaline was reported to recede gradually. Then, the phenomenon either stopped or was reversed, as was the case in some Murgia and salentine areas, where, however, sorn additional withdrawals of the isohaline have occurred. xD;The increasing saline Contamination in the salentine peninsula is confirmed by the evolution of the chlorine ion concentration (a parameter which indicates seawater contamination) over thirty years in eighteen wells. The analysis of data shows that the increased groundwater saline contamination is closely related to overdrafts. Before 1980. no significant concentration increase was reported in the majority of wells. The phenomenon became apparent in the late 80s after some dry years that result in a reduced recharge of aquifers and increased groundwater withdrawals. However, a less marked rise in salinity has been reported over the past thirty years.
Abstract: II presente lavoro intende caratterizzare ii rapporto tra alimentazione della falda idrica sotterranea del Gargano e ii prelievo dai pozzi, gli efflussi dalle sorgenti e lâesistenza di risorse idriche sotterranee ulteriormente utilizzabili. Lâarea, di circa 2.000 km2, è stata discretizzata in un reticolo a maglie quadrate di 4 km2, per ciascuna delle quali è stata stimata la litologia affiorante prevalente, la quota e la pendenza media. xD;Caratterizzato nel dettaglio ii regime termopluviometrico vigente nel Gargano, si è proceduto, per ogni celia, al calcolo delle grandezze termopluviometriche e alla definizione del bilancio idrologico. xD;Sono state raccolte tutte le informazioni disponibili relative alle portate sorgive e ai pozzi al fine di una stima, ad oggi possibile soltanto in difetto, degli efflussi sorgivi e degli emungimenti. xD;Al fine di meglio quantificare le portate sorgive, è stato definito un bilancio idrologico semplificato del lago di Varano. xD;Ii metodo utilizzato è stato positivamente validato su un piccolo acquifero campione del Gargano, lâacquifero carbonatico e superficiale di Vico-Ischitella. xD;In termini medi, dei circa 37 m3/s di precipitazioni meteoriche si stima che non meno di 8,12 m3/s finiscano per alimentare lâunità idrogeologica del Gargano. xD;Si è stimato che non meno di 3,4 m3/s alimentino sorgenti, pan al 42 % dellâinfiltrazione, mentre almeno 0,53 m3/s, pan al 7%, viene prelevato dai pozzi. xD;Ii 50 % dellâalimentazione del Gargano dà vita ad una risorsa idrica sotterranea ii cui recapito finale non è ad oggi noto. Trattasi di non meno di 4 m3/s che si versa- no a mare senza che si abbiano notizie certe sullâubicazione e la reale portata, anche approssimata, di tali sorgenti. xD;La notevole entità delle portate in gioco e la buona qualità delle acque sotterranee del Gargano impongono di considerare tale acquifero profondo come una fonte per lâutilizzazione razionale e sostenibile di risorse idriche integrative e di emergenza.
Abstract: The use of a deserted clay quarry to collect iron manufacturing-derived special wastes has been carefully assessed with a view to protecting ground water resources. The shallower ground water is of low quantity and poor quality. It is encompassed by a calcarenite aquifer, the bottom of which consists of clays. A limited calcarenite layer is found below, transgressively lying over the main Apulian carbonate shelf. The aquifer carbonate rocks enclose large ground water resources which ultimately flows into the Ionian Sea. A plastic waterproof diaphragm inert to percolation products has been installed to protect ground water against pollution hazards resulting from the disposal of industrial wastes. The dump is actually located in the vicinity of major industrial plants, the basements of which corresponds to the shallow aquifer. Both the basements and the railway cuttings greatly affect the ground water flow. Hydrogeological applied numerical calculation techniques have been used to evaluate the impact of a drainage trench on the ground water flow together with any noticeable influence of the latter on construction works and industrial plants in place.
Abstract: Mass movements varying in type and size, some of which are periodically reactivated, affect the urban area of Avigliano. The disturbed and remoulded masses consist of sandyâsilty or siltyâclayey plastic material interbedded with stone fragments and conglomerate blocks. Five landslides that were markedly liable to rainfall-associated instability phenomena were selected. The relationships between landslides and rainfall were investigated using a hydrological and statistical model based on long-term series of daily rainfall data. The model was used to determine the return period of cumulative daily rainfall over 1â180 days. The resulting hydrological and statistical findings are discussed with the aim of identifying xD;the rainfall duration most critical to landslides. The concept of a precipitation threshold was generalized by defining some probability classes of cumulative rainfall. These classes indicate the thresholds beyond which reactivation is likely to occur. The probability classes are defined according to the return period of the cumulative rainfall concomitant with landslide reactivation.
Abstract: The paper outlines the sequence of hydrogeological catastrophic events, mainly landslides and floods, recorded in the (3erace territory (SE Calabria). The instability hazard of the historical heritage due to main hydrogeological factors is characterised. The analysis of both past catastrophic events and present stability conditions of the town area allows to draw some predictive indications about the expected type of instability phenomena that can be activate during extreme rainfall events.
Abstract: This work is based on data acquisition and analysis of chronology sequences of piezometric, rainfall, thermometric and runoff data of Apulian Tableland aquifer. Methods of time series analysis are used. This approach has allowed characterising the piezometric regime and trend related to the natural recharge variation. The historical character of measurement period, last sixty years, is very important to evaluate the human effect.
Abstract: This work is based on data acquisition and analysis of chronology sequences of piezometric, rainfall and thermometric data of Apulian aquifers. Methods of time series analysis are used. This approach has allowed characterising the piezometric regime and trend related to the natural recharge variation.
Abstract: The SINTACS method for the aquifer vulnerability evaluation is experimented in a selected area of the Murgia hydrogeological unit (southern Italy). The test area is representative for the large and deep carbonate Murgia aquifer and for anthropic effects on groundwater. The experience of mapping elaboration, based a complex monitoring activity, is described.
Abstract: Si descrivono alcune tecniche di studio basate sullâimpiego di traccianti, con particolare riferimento alle esperienze maturate dalla comunità scientifica studiando le quattro unità idrogeologiche pugliesi, prevalentemente costituite da acquiferi rocciosi di natura carbonatica. La sintetica descrizione delle procedure utilizzate è integrata dall'analisi dei principali risultati conseguite in alcune esperienze. Le metodologie di studio basate sull'uso dei traccianti si sono dimostrate utili al fine di caratterizzare lâetà delle acque sotterranee e la mobilità delle stesse, le modalità di circolazione idrica sotterranea e il moto degli inquinanti. In particolare, le misure relative al contenuto in radon delle acque di falda hanno evidenziato che negli acquiferi pugliesi a maggiori concentrazioni di radon nelle acque sotterranee corrisponde una maggiore mobilità delle stesse. I traccianti radioattivi utili per lo studio delle correnti verticali sono risultati lo iodio-131 ed il bromo-82, mentre tra i traccianti stabili è stato utilizzato il cloruro di cadmio in soluzione alcolica, anche se, di recente, lâimpiego dello ioduro di potassio come tracciante ha mostrato anchâesso buoni risultati. La misura della direzione dei deflussi sotterranei in un pozzo singolo ha consentito di accertare sia lâinversione della direzione di deflusso delle acque dolci di falda in prossimità della costa, a causa delle oscillazioni del livello del mare, sia la direzione del moto delle acque di mare di invasione continentale, che in condizioni di alta marea è orientato verso il continente e che si inverte con la bassa marea.
Abstract: A free shallow aquifer is present in the Pleistocene marine terrace deposits that widely outcrops in the Brindisi district. These deposits overlay impermeable clay and calcarenite of 'Fossa bradanica' sedimentary cycle, and Mesozoic carbonate rocks of 'Calcare di Altamura' formation. In the latter a regional karsic aquifer is present. The geological analysis was carried out also using stratigraphic data from drilled holes. Those data highlight a local high variability of aquifer and impermeable clay thickness, with a mean value of 14 m and 22 m respectively. On line with the results of hydrologic accounting, particular attention was paid to the recognition of local water loss toward the karsic aquifer. A hydrogeologic study of a sample area southward with respect to Brindisi, based on detailed field survey, highlights low values of aquifer permeability, with mean value of 7,5 x 10-5 m/s. The permeability of the clay deposits underlying the aquifer is too high to avoid any water infiltration (mean value of 3 x 10-7 m/s). The water table is locally influenced by hydrographic pattern. If we consider piezometric regimen it has a month minimum in the summer end and a month maximum in March or April, with a delay of 2-3 months with respect to month extreme rainfall. The analysis of a multitemporal satellite radar image provided useful information about the water content changes of the shallow aquifer. The color hue differences shown in the color composite image of three images acquired in different season, are strictly correlated to the changes in soil moisture content. Besides, structural lineaments were recognized in that image, along which water infiltration is likely. The applicability of remotely sensed data in this kind of study is also proved by the analysis of images acquired by an infra-red videocamera.
Abstract: Sandy levels bearing bicarbonate-sodium waters, having hydraulic heads sometimes higher than ground level, have been observed during drillings in the Pliocene-Pleistocene clayey formation of the Tavoliere area. Hypotheses on origin and renewal capability of groundwater of these levels have been put forward considering usual hydrogeological parameters from discharge tests and geochemical and isotopic data.
Abstract: The main aim of study is the evaluation of water resuorces, the vulnerability and the definition of groundwater flow outline of carbonate aquifer of Volturino arid Calvelluzzo Mounts (Basilicata, Southern Italy). The aquifer vulnerability map is presented and discussed. Many parameters, as defined for SINTACS method, were used (lithology, fracture density, effective rainfall, slope, â¦).
Abstract: In the course of time the ancient Agrigento - a superb Greek city - and later urban settlements have been expanding unti1 these days over a vast area - the one described in this study. This is un area of extreme archeological interest which is characterized by the presence of a regressive type of Pliopleistocenic succession, essentially consisting of clay, sand and calcarenite. From below upwards, one can distinguish a basement from the Miocene and Pliocene epoch followed, in transgressionm by the Trubi Formation and, further up, by the Mt. Narbone and Agrigento formations. Closing the lithostratigraphic succession, the terraced marine deposits of the Sicilian and Thyrrenian, and current debris, xD;alluvial and coastal deposits can be observed. xD;In the San Leone river valley, a series of morphostructural evidences suggest that here geomorphologic dynamics is very likely controlled by ~Canberry and Valley building~ type phenomena due to complete erosion of the calcarenite plaque. Among the most outstanding evidences are: a marked westward and eastward rotation of the structural axes, on the right and left side of the torrent respectively, the presence of remoulded clay stripes and levels, also at considerable depth, and sub-horizontal discontinuities. The calcarenites are marked by a thick mesh of cracks made more pronounced by erosion and dissolution processes. Eventually, this kind of dynamics results into the separation and i subsequent detachment and collapse of calcarenite blocks from the top of the huge plaque upon which the Greek city's famous Temples were built. Some remarkable mass movements that occurred during this last century should be viewed in the light of the complex dynamics just described. Especially important are three landslides: two of them inside the area of today's Agrigento, in 1944 and 1966 respectively, and one that occurred in 1976 along the eastem side of the Hill of Temples. The 1976 slide was caused by a remobilization that followed xD;heavy rainfall: this conclusion was reached at the end of un empirical hydrological-statistica1 study based upon un origina1 method [15]. Daily cumulated rains (1 to. 180 days) were studied to cover the whole century, and this approach enables the recurrence interval of each rainfall event associated to the three investigated landslides to be determined. The results of the hydrological-statistica1 analysis were fully confirmed in the case of the 1976 slide, where it was found that rains are the main causative agent: these results were obtained by means of the physical and hydrological characterization of the soils in the landslide body and some simple calculations concerning the flow of infiltration water.
Abstract: The Niella spring is located on north Mount Sirino slope. The spring aquifer is characterized by the presence of localized fissures in carbonatic rock. The spring is the highest of the aquifer end is placed at half slope. Flinty limestone outcrops along the whole slope; the spring area is characterized by debris outcrops. Spring water comes out in these conditions for described tectonic influence on aquifer permeability. Geological-structural conditions end the effects on groundwater flow are described.
Abstract: The study Area lies on the border between Calabria and Lucania, close by the carbonate massifs of the Lauria Mountains. Like these, it is characterized by outcrops of carbonate rocks belonging to units forming part of the Campanian-Lucanian Platform. Three groups of springs located on the NW and SE sides of the carbonate massifs have been investigated. The study was conducted by means of geological and structural ground surveys accompanied by hydrogeological measurements on the springs and existing boreholes. The detailed knowledge thus acquired was then interpreted within the context of information available on the Calabrian-Lucanian Apennines. The average potential of the aquifer was determined, together with the principal methods of water flow therein, emphasis being placed on the role played by the individual groups of springs. In particular, the way fracturing influences water flow was ascertained, the hydrodynamic properties of the aquifer being quantified. The effect of karstification associated with the activity of the old Pleistocene lakes of Mercure and Noce was also established.
Abstract: A regional study has provided a preliminary outline of the resurgence characteristics of the most important springs in the Basilicata Region.
The major aquifers occur in mainly carbonate formations, generally stratigraphic-structural units deriving from the Campanian-Lucanian Platform or the Lagonero Basin. The aquicludes and local impervious plugs are of a limited variety; in most cases they consist of complex flysch formations of an essentially clayey-marly nature. Within the context of the sample of springs examined, the commonest causes of resurgence are permeability thresholds, followed by the outcropping of the piezometric surface or given permeability limits. After having classified the resurgences on the basis of the structural and lithological characteristics of the parent aquifers, the regime of the Apennine carbonate springs was reviewed and their potential was ascertained, as was the variability of flows over the observation period.
Abstract: A long and intense international research activity has by now confirmed the basic role of atmospheric precipitations on the dynamics of landslides. This paper is within the framework of such an activity and describes how solid and liquid meteoric precipitations really affect landslides. A detailed study of the empirical hydrological methods aimed at the determination of exceptional meteoric events to be correlated with landslide is performed. Finally, based on the analysis of real cases occurred in the Mediterranean environment, the opportunities offered by such an approach are discussed.
Abstract: An analysis is made of the evolutionary features of the Basento Plain landform in the stretch between Ferrandina Scalo and the sea, in context of the knowledge of the geomorphological and hydrological peculiarities of the whole catchment basin. The stretch in question lies in the south eastern portion of the Fossa bradanica where there are extensive outcrops of Plio-Pleistocene sedimentary deposits, represented mainly by blue-grey marly clays and, subordinately, sands and gravels. Between Ferrandina Scalo and Pisticci Scalo the Bradano is a braided river, while the reach between there and its mouth on the Ionian Sea is characterized by a meander belt. A detailed geomorphological examination, supported by air-photo interpretation (1953, 1973 and 1989 flights), has been made to ascertain the changes which have occurred on the plain in the last forty years. Knowledge of recent bed changes has been augmented by data derived from old maps. This has provided a picture of midifications over a hundred years or so. The principal hydrogeomorphological factors throughout the entire stretch studied can be correlated with the various fluvial trends identified. It ensues that there is substantial diversity in the relative stability conditions of the fluvial trends. More precisely, the potential instability within the meander belt can be tied in with the progressive increase in the sinuosity during the last hundred years. The in-depth hydrological study was made to highlight the main changes in use of the water resources available in the catchment, so as to establish possible relationships between man-made alterations and recent geomorphological conditions throughout the stretch concerned. It is also evident that during recent times man has been very active right up to the very banks of the river, modifying the original countryside by planting trees, growing crops and setting up industrial enterprises, once inexistent or at least located well away from the channel. On the basis of the factual picture acquired in this manner an evaluation has been made of the relationships between the recent variations in the natural geomorphological trends of the Basento in this reach, the direct and indirect upset of hydrodynamic parameters caused by man and the modifications in the landform of the flood-plain, triggered by human intervention. As the economic plan provides for a further increase in economic activities and for new hydraulic works throughout the catchment, various guidelines have been framed to optimize development.
Abstract: This work deals with the results obtained from geomorphological and hydrological investigation conducted in order to point out the complex geomorphological evolution related to a large part of the Castronuovo S. Andrea (Pz) territory, to identify the landslide typology of two different mass movements under investigation, as well as the influence caused by the rainfall. The landslide under study occurred on two opposite slopes of the low valley of torrent Mastro Ciardi, characterized by the same stratigraphic-structural, hydrogeological and geotechnical environment. The first slope e can be ascribed to a displacement of a first detachment, while the other one brat least 700io can be referred to a rimobilization phenomenon; both landslides, to a variable extent, have been influenced by tectonic joints following two different directions: NE - SW and WNW - ESE. xD;As far as the last 40 years are concerned, the morphological evolution of the areas under study has been obtained resorting to analyses, even comparative, of aerial photos at different generation; the relationship between rainfall and landslide has been identified in an empirical way through special models.
Abstract: Il contributo si basa sullâanalisi di diversi tipi di dati, elaborati fino a costituire serie storiche mensili inerenti il clima (pioggia, temperatura, giorni piovosi e intensità di pioggia) dal 1918 al 2006. Nonostante la tendenza al calo della piovosità e dellâintensità di pioggia e allâincremento della temperatura e dei giorni piovosi, si osserva la crescente ricorrenza di piene e frane, a conferma della crescente antropizzazione di aree a pericolosità idrogeologica. La discussione delle relazioni clima-frane ha evidenziato delle limitazioni ragionevolmente dovute al concentrarsi delle frane in parte del territorio e alla minore qualità del dato storico.
Abstract: La variabilità climatica spazio-temporale è stata riprodotta considerando un ampio settore dellâItalia meridionale mediante una griglia di 1 km di lato dal 1900 al 2009, ricostruendo piovosità e temperature mensili. Sono stati selezionati un bacino idrogeologico e uno idrografico in base alla disponibilità di dati di portata e al basso impatto antropico sul ciclo idrologico. Una volta definiti i modelli di trasformazione degli afflussi meteorici in deflussi superficiali o sotterranei, sono stati stimati i valori di piovosità e temperatura utilizzando uno scenario previsionale applicato a ciascun nodo della griglia. I risultati mostrano che il calo in atto della disponibilità idrica proseguirà nel periodo di previsione.
Abstract: In the present work, for a study area located in the southernmost province of continental Italy, data concerning the historical series of floods which have occurred since XVII century have been collected. Damages caused by flood events were discussed together with rainfall regime and trend (for the period in which data are available) and with main modifications due to variations in population number. The aim was to assess if the frequency of damaging floods is changing and if there is a role of rainfall and/or of anthropic modifications of land use on these changes. 150 damaging floods were analysed; 4% of the total were floods which caused damages to people, and which mainly occurred in the past centuries. Notwithstanding, the trend of damaging floods is increasing due to the effects of floods observed in the last decades. At the same time, the rainfall trend is generally decreasing, as observed at regional scale, and not significant to justify the flood recurrence increase. The population trend is characterised by a huge increase observed in the last decades. On this basis, the progressive urban enlargement, realised careless of both drainage network characteristics and extreme floods, can be considered as the main source of increasing risks due to damaging floods.
Abstract: Population growth, urbanization and global climate change have increased urban and agricultural water demands, stressing aquifer systems where groundwater is a source of water supply. The availability and utility of groundwater may further be threatened by factors stressing the quality of groundwater, such as industrial and domestic wastes and agricultural intensification. Consequences include, for example, over-allocation of groundwater, groundwater overdraft, declining well yields and land subsidence; degraded groundwater quality due to mobilization of natural pollutants (arsenic), salt contamination caused by seawater intrusion; increased demand for conjunctively used surface water, and resulting conflicts with junior users; and streamflow capture and resulting damage to ecosystems. These consequences may occur incrementally and inequitably across an aquifer. Natural environmental problems can further complicate use of groundwater and increase strain on the aquifer system; for example, underground structures, geothermal heating (such as heat islands), and geochemical evolution (such as karst formation, excessive salinity, acidity, fluoride, radioactivity, hardness, or turbidity).
To address this issue, a joint symposium on the Trends and Sustainability of Groundwater in Highly Stressed Aquifers was held during the 8th Scientific Assembly of the International Association of Hydrological Sciences, IAHS, and the 37th Congress of the International Association of Hydrogeology, IAH, in Hyderabad, India, September 2009. The symposium was organized by the IAHS International Commission on Groundwater (ICGW), supported IAH and by the IAHS International Commission on Water Quality (ICWQ).
This symposium brought together scientists, including modellers, geochemists and hydro-geologists, with water supply managers and policy makers to discuss scientific and management ideas and approaches for improving the sustainability of highly stressed aquifers. The importance of this topic was reflected in the large number of contributions to the symposium. Selected papers from this symposium have been compiled in this volume.
The editors gratefully acknowledge the assistance of the reviewers who made valuable contributions to this volume. We thank Penny Perrins and Cate Gardner from IAHS Press for their professional approach and help with the processing of the manuscripts.
Abstract: Data for the period 1821 to 2003 from 126 rain gauges, 41 temperature gauges, eight river discharge gauges and 239 wells, located in southern Italy, have been analysed to characterize the effect of recent climate change on availability of water resources, focusing on groundwater resources. Regular data are available from 1921 to 2001. Many analysis methods are used: principal component analysis, to divide the study area into homogenous portions; trend analysis, considering the MannâKendall, Student-t and Craddock tests, autocorrelation and cross-correlation analyses, and seasonal, annual and moving-average variables, applying the spatial analysis to each variable with a geographical information system approach. A widespread decreasing trend of annual rainfall is observed over 97% of the whole area. The decreasing trend of rainfall worsens or decreases as mean annual rainfall increases; the spatial mean of trend ranges from 20.8 mm/a in Apulia to 22.9 mm/a in Calabria. The decrease in rainfall is notable after 1980: the recent droughts of 1988â1992 and 1999â2001 appear to be exceptional. On a seasonal basis, the decreasing trend is concentrated in winter; a slight positive trend is observed in summer, the arid season in which the increase is useless as it is transformed into actual evapotranspiration. The temperature trend is not significant and homogeneous everywhere if the temperature increase seems to prevail, especially from about 1980. Net rainfall, calculated as a function of monthly rainfall and temperature, shows a huge and generalized negative trend. The trend of groundwater availability is so negative everywhere that the situation can be termed dramatic for water users, due not only to the natural drop in recharge but also to the increase of discharge by wells to compensate the non-availability of surface water tapped by dams, as a direct effect of droughts.
Abstract: Remarkably fast socio-economic development over the past few decades stressed the Region of Apuliaâs hydrogeology by originating different hazard sources. Massive groundwater withdrawal increased and aquifers were also increasingly bound to be a sort of ultimate receptacle for domestic and industrial wastewaters. The entire region underwent twofold human-origin pollution caused by saline seawater and chemical-physical intrusion. xD;The importance of impaired natural resources and situation severity called for an approach based on all scientific knowledge available, supplemented by up-to-date investigations on groundwater. The main objective was to identify quality trends availability degradation and groundwater resource risks, by using different GS integrated methodologies and developing management tools, the latter to be simple, quick, affordable and as low cost as possible. The proposed approach was based on groundwater vulnerability assessment and use of an automatic hydrogeology monitoring network, the analysis of rainfall, air temperature, river flow yield time series and, more importantly, piezometric level checks to quantify groundwater availability changes, salinity trend analysis to assess changing seawater intrusion effects, groundwater quality schematic mapping with available chemical- physical laboratory data and multi-parameter logging for fast groundwater quality classification. Each tool used is summarised with the main results ofapplications to Apuliaâs aquifers.
Abstract: Rainfall is the most common cause of landslides. The cost of Rainfall Triggered Landslides (RTL) is not well documented and often unobtainable. In areas where they do not pose a threat to life, great damage is caused to farmland and communication infrastructures and pasture bio-mass production is heavily reduced (Table 1). In Japan more than 10,000 RTL are reported every year which claim the lives of some 400 persons (Fukuoka, 1980); A single event has killed 100 persons and inflicted property damages estimated at 300 billion yen Shimizu (1988).
Given the importance of the topic, some 138 papers dealing with RTL were selected and key information was collected in a database. Nearly 82 % of all records are local investigations carried out in 23 countries. Italy provides the largest sample as for authors' nationality and widespread proneness to landslides; followed by United States (15 %), Hong Kong (8 %), Japan and United Kingdom. About 21 % of all selected papers are methodological research or syntheses and comparisons of different methodologies. Investigations refer to widespread landsliding (69 % of AD) (that is the Available Data number for each database field), the remainder corresponds to single or few landslides. A landslide classification proposed by Hutchinsons (1995) and based on the maximum depth of failure (Vm), is adopted in this work. About 40 % of AD are intermediate or deep-seated landslides (Vm > 10 m), that include all reactivations, the rest are shallow or superficial landslides, generally first-time movements. The most frequent types are: flows, translational and rotational slides, slips, avalanches and creep, decreasing order (Cruden & Varnes 1996) with soil or debris generally constituting the landslide bodies. Daily (54 % of AD), hourly (28 %), monthly (15 %) and yearly (4 %) rainfalls are used as input. Roughly 49 % consider cumulative rainfall (a rain water height obtained adding regularly monitored rainfall) of different duration. The prevalent approach is empirical, statistical or hydrological-qualitative; one out of four is partially physical and often uses numerical modelling. About 10 % combine rainfall effect characterisation with geotechnical stability analysis. The results of research in progress have been summarised.
Abstract: Damaging Hydrogeological Events (DHEs) are episodes of severe weather conditions characterised by strong winds, heavy rainfall, landslides, flooding, and sea storms. Each type of phenomenon developing during DHEs is characterized by a proper dynamic and, according to the social and economical framework in which develops, it can cause different impacts on people and properties. Despite during storms all these phenomena occur at the same time (or in a short while), often amplifying damage and hinting emergency management, studies available in literature tend to analyze each type of phenomenon separately, supplying a fragmentary framework of either causes (rainfall) and effects (damage).
A database concerning DHEs occurred in Calabria (southern Italy) since 1800 has been recently updated, by continuing a historical research which has been started since 2000. Basing on this huge amount of data (more than 10,000 records), an analysis of the series of DHEs occurred in a selected area/period is carried out. Both the methodological framework for DHEs analysis, based on damage classification and a classification of different DHEs types are presented.
Abstract: The quality of groundwater of Apulian carbonate aquifers is severely affected by salt quality degradation due to seawater intrusion which reduces the availability of high quality groundwater. To reduce these risks, some regional regulations were defined from seventies with the purpose to control the number of wells, the location and the authorised well discharge. The practical effects of these management criteria, the temporal and spatial trend of recharge, groundwater quality and seawater intrusion effects are discussed. Proposals for new management criteria are defined.
Abstract: The quality of groundwater of Apulian carbonate aquifers is severely affected by salt contamination due to seawater intrusion. Due the scarcity of surface water resources, the characterization of groundwater quality degradation risks and of spatial and temporal trend of degradation are particularly important in the region.
To pursue these results considering the risk of salt contamination due to seawater intrusion, a simple salinity threshold approach, based on the determination of a single value dividing fresh groundwater from seawater contaminated groundwater, is proposed for Apulian groundwater. The threshold can be considered equal to 0.5 g/l for the Apulian karstic and costal aquifers. The spatial trend of 0.5 g/l salinity contour line in the period 1981-2003 is characterized. Along the areas close to the Adriatic and Ionian shoreline groundwater saline contamination is resulted to be a long-standing phenomenon. Only the Murgia interior and a restricted strip in the middle of the Salentine Peninsula have not been contaminated so far.
The salt contamination is also characterized considering 17 time series of monthly chloride concentration, a parameter which can highlight the seawater contamination effects. Data from 1968 to 2001 are considered and compared with rainfall and temperature time series. The increased saline contamination is closely related to droughty years and to the increasing discharge by wells. Before 1980, no significant concentration increase was reported in the majority of wells. The phenomenon became apparent in the late 80s after some dry years that result in a reduced recharge of aquifers and increased groundwater withdrawals. Time series of mean annual values of specific electrical conductivity are also discussed.
It is confirmed the existence of areas considerable protected from the seawater intrusion, of areas exhibited in serious manner to the salt pollution and, finally, of an immense portion of territory in which the quality of the groundwater depends exclusively from our capacity to manage the water resources.
Abstract: The coastal karstic aquifer of Mt. Oyramanges (1864 m asl) is located in the Vlora Bay, along the Adriatic coast. The quality of the spring water there is so high that it is used to supply the drinking supply of the second largest Albanian town, Vlora. Starting from a geological and tectonic conceptualization of the area, a GIS approach based on long-term rainfall, temperature and river yield time series has been used to define hydrologic balance. The assessment of recharge and the measurement of sub-aerial spring discharge permit the rough assessment of submarine groundwater discharge. The definition of the flow domain and of groundwater chemical features is pursued with an on-going survey which includes chemical and isotopic analyses of rainfall, groundwater and sea water.
Abstract: Lo studio caratterizza le modfIcazioni tendenziali delle principali vat-lab iii che determinano la disponibilità di risorse idriche. Verficata la recente ed anomala incidenza di pet-lodE siccitosi, Si valutano gil effetti tendenziali sulla disponibilità di acque sotrerranee.
Si utilizzano datE mensili inerenri le precipitazioni meteoriche e le temperature atmosferiche di 126 stazioni collocate in Italia meridionale, tra il 1821 e ii 2001. Si osservano cali tendenziali della piovosità effettiva in 114 stazioni con trend negativi fino a -9 mm/anno. La tendenza negativa riguarda piI1 del 95% dell âarea; ii test di Mann-Kendall ne con fermo la sign,fIcativitâ su scala locale e regionale. hi particolare, emerge un consistente deficit di precipitazioni a partire dal 1980. La tendenza è negativa doll âautunno alla primavera ed è molto accentuata in inverno. Se le variazioni tendenziali di temperatura non sono risult ate evidenti ed omogenee, ii calcolo delia piovosità efficace ha segnalato una tendenza al calo ancora più grave di quanto osservato per la piovsità effettiva, stante la maggiore incidenza del calo pluviometrico nei mesi umidi.
Gil effetti suile acque sotterranee sono valutati mediante serie storiche mensili, dal 1965 al 2003, relative a 63 stazioni piezometriche ubicate nei principali acquferi della Puglia. Mediante metodi di statistica delle serie storiche si caratterizzano I rapporti intercorrenti tra piovosità , temperatura e variazioni piezornetriche. I trend piezometrici risuitano negativi:
equivalgono a cali piezomefrici considerevoli in tutte le unità idrogeologiche.
Abstract: The paper deals with the groundwater availability along the lonian coastal plain (Southern Italy), between the mouths of Sinni and Bradano Rivers. Subjected to intense agricultural and tourism activities, the availability of the tapped groundwater is seriously important for the economic growth ofthis coastal area, especially due to the increasing frequency of droughts. The stratigraphical and hydrogeological set-up of the area as the geochemical features of the groundwater arise from the data analysis of 1130 boreholes, widespread over the whole area and from 1.3 up to 423 meters deep. The aquifers of the area could be distinguished in two types. The former encloses aquifers constituted by marine terraced deposits and alluvial river valleys deposits. The latter includes that one of the coastal plain deposits. It is the most interesting for practical utilisation and it is considered in the paper. xD;The analysis of long time series is based on piezometric data (1927 to 1984), monitored by 60 wells, temperature, rainfall and river discharge data. The piezometric regimen and the maximum piezometric variation are characterised. The trend analysis, the autocorrelation and the crosscorrelation were applied to all variables. As a result, the modification of groundwater availability was characterised considering the spatial variation of the hydrogeological conditions. The relationships existing between rainfall, temperature, river discharge variations and piezometric surface height. xD;
Abstract: Computer techniques such as Geographic Information Systems are applied to the evaluation of the vulnerability of a deep carbonate aquifer. xD;The study area, of about 150 km2, is located in the low Murgia Plateau (Apulia) and characterized by Mesozoic limestone and dolomite rocks of several thousand meters thickness. A wide and thick aquifer resides in these carbonate rocks. Its groundwater flows toward the sea mainly under pressure and with maximum piezometric level of about 200 m a.s.l.. Due to their high quality, the water resources of this aquifer are particularly valuable for the local communities and therefore must be protected from pollution and inappropriate use. xD;The vulnerability map of the aquifer is an indispensable tool for the effective management of groundwater resources and to support environmental planning. Several approaches have been proposed by different authors to evaluate intrinsic vulnerability. Most of the methods for detailed vulnerability mapping are based on the integrated analysis of several variables using different algorithms. Geographic Information Systems are advanced computer tools for the analysis of georeferenced data in 2D and 3D and can be effectively applied to the implementation of evaluation models. In this study the SINTACS evaluation method was implemented in a GIS and a digital vulnerability map produced. xD;The different data taken into consideration in this analysis, such as depth to water, actual infiltration, pollution attenuation capacity of unsaturated zone, land cover, hydrogeological features of saturated aquifer, hydraulic conductivity, terrain slope, geology and geological structures, were georeferenced and converted into digital form. Each variable corresponds to a separate data layer made of graphic and attribute data. xD;The computerized multilayer analysis performed by the GIS is time effective and leads to more comprehensive and accurate results with better spatial resolution.
Abstract: The literature contains many examples, which demonstrates the importance of climatic conditions, particularly of rainfall but also temperature, on landslide activation. Normally landslides occur during specific hydrologic conditions; the relative importance of each factor will however vary with the landslide type.
Heavy rains are one of the main natural factors producing landslides as they may cause pore pressure to increase on slopes or can create adverse seepage conditions, modify the slope's geometry as a result of erosion and originate swelling and softening processes in clay soils.
According to their different behaviour, it is necessary to distinguish shallow or deep-seated landslides, first-time or reactivated landslides, the nature of landslide body (terrain or rock) as well as the hydrogeological nature of soils.
Shallow landslides in soils and weathered rocks are often generated on steep slopes during the most intense part of a storm (lasting from minutes to several hours). The higher permeability of the outermost portion of the slope, compared to the bedrock below, allows for the creation of a temporary perched water-table, inducing the progressive increase of pore-water pressure.
On the other hand, deep-seated landslides can be mobilised as a consequence of moderate intensity rainfalls lasting several days, owing to the longer recharging time required for ground-water level to rise and cause a significant build up in pore-water pressure.
Pioneer studies, concerning landslides triggered by rainfalls, go back to '30s. Were selected 138 papers and key information was collected in a database. Nearly 82 % of all records are local investigations carried out in 23 countries. Italy provides the largest sample as for authorâs nationality and widespread proneness to landslides; followed by United States (15 %), Hong Kong (8 %), Japan and United Kingdom.
Two main approaches have been used to investigate rainfall-induced landslides:
-empirical or semi-empirical relationships, using statistical correlation and forecasting techniques;
-deterministic modelling of groundwater recharge and pore-water pressure changes.
Studies concerning the first type of approach have reached interesting results about combination of antecedent rainfall and rainstorms intensity able to trigger widespread soilslip activation in specific geological, morphological and climatic settings.
Relationships between rainfall intensities and duration associated with shallow landslides and debris flows activation has also been found and they are often used for warning purposes.
For the activation of widespread mass movements, some authors underline the role of an effective rainfall period ended by a pronounced increased of rainfall intensity; in this situations hazard precursors may be considered as a combination of cumulate rainfall and rainfall intensity.
The second approach requires the development of a clear picture of the modes of water flow on and below the ground surface: where groundwater flow is concerned, attention is focused on both the saturated and the unsaturated zones and complete hydrological models of slopes must be defined.
The present paper is a critical overview of recent international research activity on this subject. Methods and experiences are compared and classified. Some author's direct experiences are utilised for these purposes.
Abstract: La nota ricostruisce la serie dei principali fenomeni di dissesto idrogeologico registrati in epoca storica nel territorio comunale di Gerace (Calabria sud-orientale) e analizza i rischi di degrado del patrimonio storico-artistico connessi allâinnesco di tali fenomeni. Lâanalisi degli eventi pregressi e delle attuali condizioni del centro abitato, effettuata considerando anche gli interventi realizzati a protezione dellâedificato, consente di trarre alcune indicazioni sulle più probabili tipologie di dissesti attesi, nei diversi settori dellâabitato, in occasione di eventi pluviali estremi.
Abstract: The remarkable and rapid socio-economic development over the past few decades has further stressed the Apulian hydrogeological system. The whole Apulian groundwater has undergone a twofold pollution, all originated by human action: saline pollution evolves progressively as it affects increasingly large portions of land, biological and chemico-physical pollution is gaining importance and is mainly concentrated around urbanised areas. The latter is due to the circumstance that the aquifers are increasingly bound to become a kind of ultimate âreceptacleâ for domestic and industrial waste waters. In order to characterise the features of human-related pollution, data was gathered by a monitoring network-encompassing 157 wells, some of which hundred meters deep, and 19 coastal springs. Periodical water samples were taken from the network to be submitted to chemical, physical and bacteriological analyses. The effects of human activity on groundwater pollution and depletion are so characterised.
Abstract: Nel lavoro vengono illustrati ed interpretati i risultati degli studi geologici, geomorfologici ed idrologici condotti al fine di accertare i caratteri geomorfologici ed evolutivi di un complesso e profondo movimento di massa e, in particolare, ii ruolo svolto dalle piogge sulle sue periodiche rimobilitazioni prodottesi nd recente passato e che si sono rese responsabili di significativi daimi alla linea ferroviaria Potenza - Metaponto
Abstract: Apulia is affected by two types of human-related pollution: salt contamination and chemico-physical and biological pollution. The special severity of the situation calls for a rigorous approach based on available scientific knowledge and supplemented by up-to-date investigations of the evolution of groundwater quality. Particularly useful are to this end the multi-parameter logs which have been executed along the water column of the well, through the monitoring of temperature, salinity, pH, dissolved oxygen and oxidation-reduction potential of groundwater. This method, which has been tested in 120 wells over one year, has allowed to detect some typical trends of the parameters under study. These types, which are rather recurrent in space and time, allow an extensive use of the suggested method which can be easily applied to the preliminary detection of the hydrogeological conditions which determine the chemical and physical nature of groundwater and the occurrence of human- or salt-related contamination.
Abstract: In the past decades, major landslides have taken place after heavy and relentless rainfalls and caused severe damage to a number of urban centres and facilities.
The unexpected plentiful rain fallen over the course of the year contributed to the severe hydrogeological crisis which struck Basilicata (Southern Italy) in 1976. Large floods and extensive deep-seated landslides were repeatedly reported in the area. For the purpose of this paper, some major landslides that occurred late in 1976 were selected. The extremely heavy precipitation fallen over the region throughout the year was measured by some rain-gauge stations. Precipitation records were compared to average rainfalls measured at the same location. For one of the landslides under examination, a statistical and hydrologic model was used in order to assess the recurrence interval of cumulative rainfalls of varying duration.
The amount of precipitation in 1976 is particularly striking in terms of extent of the area covered and duration of heavy rainfall , both higher than average, and intensity of rainfall of a given duration.
Abstract: Throughout 1995 is most of the territory of Taranto, heavy rainfalls have followed dry years of infrequent precipitation. The trend has persisted for three more months in 1996, thus leading to multiple calamitous events. Between January and February 1996, many municipalities in the province of Taranto have been hit disasters due to such unprecedented rainfalls. Hydrologic events of various duration and intensity and altered climatic conditions have resulted in simultaneous disasters, namely river overflowing, water-logging, massive flooding, extensive landslides, intense erosions and severe damage to transport and water facilities. The hydrogeologic disasters were not triggered by the extraordinary amount of surface flowing water alone. Also underground water bodies, subject to significant recharge have increased spring water flows, somewhere acquiring an artesian attitude and thus steadily worsening the existing hydrogeologic emergency. A characterization of the newly arisen set of conditions has been atternpted by studying daily rainfall rates, peak annua1 precipitation lasting 1, 3, 6, 12 and 24 hours and temperature. The examination of the hydrogeologic disaster within an extended time frame has indicated the prominerzt role played by long lasting drought on the efficiency of the watercourse network and on the fragili01 of the territory. 1t follows that the drawbacks of different natura1 phenomena have overlapped in the Jirst three months of 1996 in the province of Taranto. Moreover; the effects of these phenomena have been occasionally enhanced by the irnpact of human activity unsuitable maintenance of the hydrographic network and poor contro1 over the territory. A true natura1 calamity has thus occurred which has brought about particularly severe situations in some areas where the risk of subsequent ydrogeologic disasters remains.
Abstract: Research carried out in recent years by CERIST operating unit has investigate Apulian hydrogeological unit groundwater. Different technologies have been applied by researchers, such as: multiparameter hydrogeochemical studies of the evolution of groundwater chemism; thermal infrared survey of coasts where springs were found; studies of varied space distribution of piezometric heads, salinity and water temperature; studies of hydrogeological relationships existing between various underground and sometimes very deep "mains d'eau" studies of protection methods of groundwater against saline pollution. xD;Recently, research has also focused on human-related pollution of Apulian aquifers. This subject has aroused great topical interest following the continuous and senseless use-of the subsoil for waste water collection. Authors particularly refer to the health, environmental and economic emergency that hit our Region in 1994. The effects of human activity on groundwater pollution and depletion are described, alongside indirect effects connected with continental seawater intrusion. Therefore, the need is felt to protect regional groundwater resources and recycle water wasted so far. A more rigorous discharge of depurator waste water into the subsoil 15 strongly recommended.
Abstract: The aim of this work is to highlight the influence exerted by meteoric events on landslide triggering. Taking into account the main geomorphological and hydrogeological features at the mass movements, simple hydrological/statistical methods are suggested. Cumulative daily rainfalls over 1 to 180 days are studied to determine probability distribution functions. Hence the critica1 rainfall period is determined for a specific landslide and the return period of the hydrological event associated with the landslide is quantified.
Abstract: This contribution characterizes some remarkable cases of saline contarnination of the groundwater. It is known that the causes of the saline contamination are manifold, the principal causes are: the continental intrusion of the marine waters; the upcoming, along the hydrographic network, of marine waters, the leaching of soils and rocks and, finally, the human activity. The effects of this are complex and not easly to describe in a schematic way. The conmbution concludes describing the main methods to prevent, remedy and stop the salinitazion.
Abstract: Gli ipogei di Agrigento, dell'antica città greca Altragas, costituiscono una grandiosa opera di ingegneria idraulica e di captazione idrogeologica. Gli ipogei costituivano una rete di acquedotto che serviva, nei momenti di massimo splendore, una città abitata da circa duecentomila persone, permettendo lo sviluppo economico e sociale della più fulgida delle città della Magna Grecia. Un insieme di pozzi, cunicoli e serbatoi, scavati in una tenera roccia calcarenitica, correva con continuità lungo le pendici della valle dei Templi, a profondità dal piano campagna variabili e non superiori a 30 m.
Abstract: La falda idrica sotterranea che si esamina interessa un acquifero poroso e costiero disposto lungo la costa ionica lucana, tra le foci dei fiumi Bradano a Nord e Sinni a Sud. In particolare, viene caratterizzato il complesso di relazioni esistenti tra i corpi idrici superficiali e sotterranei in un'area che si estende per oltre 20 Km lungo la costa e per 6 Km verso l'interno. In tale area affiorano estesamente, costituendo l'acquifero per la falda idrica in studio, depositi detritici, sia marini che continentali, di natura ciottolosa, sabbiosa e argillosa. L'ambiente in cui si muovono le acque sotterranee in studio è condizionato dalla modesta soggiacenza della stessa, dalle profonde incisioni fluviali con foce sullo Ionio e dai relativi deflussi idrici, dall'infiltrazione naturale e non, dovuta quest'ultima all'intensa irrigazione, dagli afflussi provenienti da altri corpi idrici sotterranei, dalla presenza del mare nonchè dall'uso intenso nei mesi estivi della risorsa idrica sotterranea esaminata. Per caratterizzare il regime della falda in tali complesse condizioni sono stati raccolte numerose serie di dati idrologiche. I dati pluviometrici e termometrici, relativi a un periodo di tempo pari a oltre 60 anni, hanno permesso di caratterizzare il clima e studiare l'infiltazione. I dati idrometrici, disponibili per circa 40 anni, hanno permesso di caratterizzare il regime fluviale dei principali corsi idrici. La raccolta, infine, di dati piezometrici relativi a una rete attiva per circa 30 anni ha permesso di perseguire le finalità di studio che il lavoro illustra. Alcune metodologie statistiche sono state applicate al fine di caratterizzare il regime della falda e per evidenziare l'influenza che su di essa hanno i corpi idrici superficiali e l'azione dell'uomo. Lo studio ha considerato l'evoluzione temporale dei fenomeni, utilizzando anche l'analisi spettrale e di correlazione, nonchè spaziale, mediante approcci tipici della Geostatistica.
