modelling coastal ground and surface water interactions using an integrated approach beach water table fluctuations have an impact on the transport of beach sediments and the exchange of solute and mass between coastal aquifer and nearby water bodies details are given of the refinement of a dynamically integrated ground and surface water model and its application to study ground and surface water interactions in coastal regions the depth integrated shallow water equations are used to represent the surface water flow and the extended darcy s equation is used to represent the groundwater flow with a hydrostatic pressure distribution being assumed to apply for both these two types of flows at the intertidal region the model has two layers with the surface water layer being located on the top of the groundwater layer the governing equations for these two types of flows are discretized in a similar manner and they are combined to give one set of linear algebraic equations that can be solved efficiently the model is used to predict water level distributions across sloping beaches where the water table in the aquifer may or may not decouple from the free water surface five cases are used to test the model for simulating beach water table fluctuations induced by tides with the model predictions being compared with existing analytical solutions and laboratory and field data published in the literature the numerical model results show that the integrated model is capable of simulating the combined ground and surface water flows in coastal areas detailed analysis is undertaken to investigate the capability of the model

effects of geology and human activity on the dynamics of salt water intrusion in three coastal aquifers in southern spain mathematical modelling of salt water intrusion processes in three aquifers on the southern coast of spain rio verde rio velez and castell de ferro reveals that although all three systems are subject to the same climate and seasonal over exploitation geological and human factors have very different effects on the dynamics of contamination in the rio verde aquifer the most important influence is the high volume of extractions occurring during the dry season in rio velez the intrusion is strongly controlled by infiltration of water from the river to the aquifer and in the castell de ferro system an intensely karstified carbonate massif lying in contact with both the sea water and the detrital aquifer represents the main entrance point for influx of sea water and subsequent washing of the aquifer we have undertaken a mathematical simulation of various possible measures to counteract intrusion according to the specific characteristics of the process in each aquifer these measures include artificial recharge use of natural recharge from the river as a hydraulic barrier and the construction of a low permeability barrier

numerical simulation and evaluation of groundwater resources in a fractured chalk aquifer a case study in zinder well field niger groundwater is often a unique water source for agriculture industry and domestic use for local inhabitants in semi arid african continent owing to shortage of surface water and rainfall it is of significance to quantify and assess the groundwater resources for local sustainable development in order to correctly evaluate groundwater resources of zinder well field with fractured media in zinder niger a conceptual model of hydrogeology was set up by a geological and hydrogeological survey for simulating the real conditions a large multi well pumping test with designed pumping rate was conducted in addition a two dimensional finite element transient flow model was developed to simulate groundwater flow at the site results show that generally good agreements have been found between the simulated and observed hydrogeology heads for the test the hydraulic parameters were obtained from the pumping test a 11 year prediction of groundwater resources has been made under three exploitation schemes respectively and it indicates that the well field can offer 7 000 m3 day when the aquifer remains confined an optimal scheme of exploitation is provided

relict caves as evidence of landscape and aquifer evolution in a deeply dissected carbonate terrain southwest edwards plateau texas u s a abstract caves lying well above valley floors and within narrow ridges of carbonate rocks in the deeply dissected southwest edwards plateau texas provide considerable information about the geomorphic history of the region and the evolution of the edwards trinity aquifer in the sonora area horizontally extensive cave passages occur at three distinct levels along massive burrowed dolomitic beds in the cretaceous segovia formation passages lying beneath a resistant caprock consist of long corridors barren of speleothems however in the vicinity of the caprock edge passages are modified by collapse and stoping mazework and speleothem deposition conduits are generally oriented down the regional dip and guided by dominant ne trending fractures upper cave levels developed first but lower passages were excavated as piezometric surfaces dropped in response to valley cutting cavern collapses blocked flowpaths in places and ensuing floodwaters enlarged passages formed maze sections and promoted development of diversion routes around these constrictions collapse at the caprock edge has enhanced retreat of valley slopes and headward erosion of streams in the langtry area caves developed in the cretaceous devils river formation are up to 113 m deep the devils river formation is a stratigraphically homogeneous high purity limestone in which fractures are few but vertically extensive incision of the rio grande and nearby streams has locally exposed up to 70 m of the devils river formation inducing steep hydraulic gradients that have promoted bathyphreatic circulation and development of deep cave systems horizontal passages are relatively short and are connected by vertical shafts and steeply inclined corridors the two localities have experienced similar climates and dissection in topography but the relationship of stream incision to geologic structure stratigraphy and lithology has differed significantly enough to produce long horizontal caves within the shallow phreatic zone around sonora and deep vertical caves in the deep phreatic zone around langtry

simulation of groundwater flow and environmental effects resulting from pumping in coastal lowland plains increased water demand on a limited water resource has resulted in declining groundwater levels land subsidence and saltwater encroachment in southwestern kyushu japan a sinking of the land surface due to over pumping of groundwater has long been recognized as a problem in the shiroishi lowland plain in this paper an integrated model was established for the shiroishi site using the modular finite difference groundwater flow model modflow by mcdonald and harbaugh 1988 and the modular three dimensional finite difference groundwater solute transport model mt3d by zheng 1990 to simulate groundwater flow hydraulics land subsidence and solute transport in the alluvial lowland plain firstly problems associated with these groundwater resources were discussed and then the established model was applied the simulated results show that subsidence rapidly occurs throughout the area with the central prone in the center part of the plain moreover seawater intrusion would be expected along the coast if the current rates of groundwater exploitation continue sensitivity analysis indicates that certain hydrogeologic parameters such as an inelastic storage coefficient of soil layers significantly contribute effects to both the rate and magnitude of consolidation monitoring the present salinization process is useful in determining possible threats to fresh groundwater supplies in the near future in addition the integrated numerical model is capable of simulating the regional trend of potentiometric levels land subsidence and salt concentration the study also suggests that during years of reduced surface water availability reduction of demand increase in irrigation efficiency and the utilization of water exported from nearby basins are thought to be necessary for future development of the region to alleviate the effects due to pumping

hydrogeology of karst aquifer systems in sw turkey and an assessment of water quality and contamination problems the aim of this research is to determine the relationship between groundwater flow and water quality of different ground and surface water basins in the southwest turkey in addition groundwater vulnerability is assessed taking into consideration groundwater flow and quality the autochthonous beydaglari limestone is the major karstic aquifer in the region according to the groundwater level map of alluvium aquifers in the basins groundwater discharge toward the carbonate aquifer is direct and indirect the hydrogeological connection between ground and surface water basins occurs via the karstic aquifer located at the bottom of the alluvium bottom in egirdir lake water also discharges in the karstic aquifer via karstic sinkholes at the western border of the lake in the research area general groundwater discharge is toward the mediterranean sea by means of autochthonous carbonate system according to hydrogeological investigations research of lineament and hydraulic conductivities this result is supported by the locations of lineaments and shore springs discharging from the limestone in addition spreading of contaminants via karstic aquifer to great distance has been clearly identified

application of galdit index to assess the intrinsic vulnerability to seawater intrusion of coastal granular aquifers groundwater within coastal aquifers is considered a very sensitive natural resource since its quantity and quality is threatened by anthropogenic activities as well as global and climate changes the major environmental hazard with respect to coastal aquifers is the phenomenon of seawater intrusion and is more pronounced in the mediterranean basin in the light of smart management of such hydrogeological systems galdit index was introduced in the form of a numerical ranking system that aims to assess the vulnerability of such aquifers to seawater intrusion this paper provides an application of galdit vulnerability index for a typical mediterranean alluvial aquifer under variable hydrogeological conditions in different research periods 1992 and 2004 the results proved the significance of the piezometric conditions of the aquifer with respect to its vulnerability to seawater intrusion

exploring the use of alternative groundwater models to understand the hydrogeological flow processes in an alluvial context tiber river rome italy the first step of the application of a groundwater model to a specific site is the identification of the conceptual model in this paper a methodology to compare different conceptual models is proposed such a method consists in the parallel run of simple groundwater models based on different conceptual models and in the evaluation of each model fitting the case study proposed to illustrate this approach belongs to the alluvial series of the tiber river rome italy

analysis of surface black carbon distributions during ace asia using a regional scale aerosol model 1 the regional scale aerosol transport model cfors is used in the analysis of black carbon bc observed at five remote japanese islands during the ace asia experiment bc is modeled online in the regional scale meteorological model using emissions estimates for 2000 two model experiments are conducted 1 a control run that includes all the bc emission and 2 a sensitivity run without open biomass burning emissions to clarify the impact of biomass burning on the bc levels in the western pacific the regional aerosol model cfors is shown to accurately reproduce many of the important features observed model analysis shows that the spatial and temporal distributions of black carbon between the northern sites rishiri and sado located in the japan sea and the southern stations hachijo chichijima and amami oshima in the western pacific ocean are under different flow regimes it is shown that the major synoptic features controlling bc levels are associated with outflow in the warm conveyor belt of traveling cold fronts and the subsequent postfrontal transport at the northern stations rishiri and sado elevated bc concentrations are calculated to be mainly below the heights of 2000 m and the biomass burning fraction is estimated to be below 20 at the southern sites e g chichijima the contribution due to biomass burning reaches 32 at the surface and 52 in the free atmosphere cfors results indicate that the major black carbon source and transport height are different between the northern and southern sites

management of coastal aquifers based on nonlinear optimization and evolutionary algorithms abstract a method of assessing the optimum pumping rates of coastal aquifers based on nonlinear optimization and evolutionary algorithms ea is developed the objective is to maximize the total pumping rate while protecting the wells from sea water intrusion the formulation of the constraints is based on numerical simulation of the freshwater flow equations the simulation model is based on the sharp interface and the ghyben herzberg approximation and is applicable to unconfined aquifers and steady state flow the single potential formulation of water resour res 12 1976 1165 is followed and the governing equations are solved numerically using finite differences the numerical model can handle aquifers of complex shapes nonuniform hydraulic conductivity nonuniform distribution of surface recharge etc the constraints are nonlinear with respect to the decision variables resulting in a nonlinear optimization problem two optimization methods are investigated specifically sequential quadratic programming sqp and evolutionary algorithms ea sqp requires less computer time than ea but can get stuck on local optimum solutions the simulation and optimization methodology is applied to a real unconfined coastal aquifer in the greek island of kalymnos for determining the optimal pumping rates while protecting the wells from sea water intrusion

groundwater quality of porous aquifers in greece a synoptic review greece is dependent on groundwater resources for its water supply the main aquifers are within carbonate rocks karstic aquifers and coarse grained neogene and quaternary deposits porous aquifers the use of groundwater resources has become particularly intensive in coastal areas during the last decades with the intense urbanization tourist development and irrigated land expansion sources of groundwater pollution are the seawater intrusion due to over exploitation of coastal aquifers the fertilizers from agricultural activities and the disposal of untreated wastewater in torrents or in old pumping wells in the last decades the total abstractions from coastal aquifers exceed the natural recharge so the aquifer systems are not used safely over exploitation causes a negative water balance triggering seawater intrusion seawater intrusion phenomena are recorded in coastal aquifer systems nitrate pollution is the second major source of groundwater degradation in many areas in greece the high levels of nitrate are probably the result of over fertilization and the lack of sewage systems in some urban areas

modelling hydrostratigraphy and groundwater flow of a fractured and karst aquifer in a mediterranean basin salento peninsula southeastern italy the control exerted by the hydrostratigraphic structure on aquifer recharge groundwater flow and discharge along the coastal areas of a mediterranean basin salento peninsula about 5 000 km2 wide southern italy is assessed through the development and application of a groundwater flow model based on the reconstruction of the hydrostratigraphic architecture at the regional scale the hydrostratigraphic model obtained by processing surface and subsurface data is applied to map the top of the main aquifer which is hosted in the deep hydrostratigraphic unit corresponding to cretaceous and oligocene limestones with complex geometrical relationships with the sea it is also used to estimate the aquifer recharge which occurs by percolation through overlying younger sediments with low permeability these data are completed with information about the soil use to estimate water abstraction for irrigation and with literature data to estimate the water abstraction for drinking and industrial purposes the above sketched conceptual model is the basis for a finite difference groundwater 2d pseudo stationary flow model which assumes the following fundamental approximations the fractured and karst limestone hydrostratigraphic unit can be approximated at the model scale as a continuous medium for which the discrete darcy s law is valid the transition zone between salt and fresh water is so small with respect to the grid spacing that the ghyben herzberg s approximation for a sharp interface can be applied along the coastline different boundary conditions are assigned if the top of the limestone hydrostratigraphic unit lies either above the sea level the aquifer has a free surface and fresh water is drained or below the sea level the aquifer is under pressure and the contact with sea occurs off shore the groundwater flow model correctly predicts the areas where the aquifer is fully saturated with salt water

a parsimonious model for simulating flow in a karst aquifer abstract this paper describes the hydrologic system associated with the barton springs portion of the edwards aquifer and presents a lumped parameter model capable of reproducing general historical trends for measured water levels and spring discharge recharge to the aquifer was calculated based on flow loss studies of the creeks crossing the recharge zone and on estimates of the rate of diffuse infiltration of rainfall flow measurements on each creek above and below the recharge zone were used to develop a relationship between flow above the recharge zone and the rate of recharge the five cell groundwater model each cell corresponding to one of the watersheds of the five main creeks crossing the recharge zone was developed to support the management objectives of the city of austin the model differs from previous models in that the aquifer properties within cells are allowed to vary vertically each cell was treated as a tank with an apparent area and the water level of a single well in each cell was used to characterize the conditions in that cell the simple representation of the hydrologic system produced results comparable to traditional groundwater models with fewer data requirements and calibration parameters 1997 elsevier science b v

stratigraphic and geophysical integrated methodologies for the interpretation of sulphur water formational environment in salento italy abstract the salento coal deposits south eastern italy are unutilized because these deposits are thin and nearly uneconomic but they have a high scientific and economic value due to their high organic sulphur content the studied area is located in the western salento peninsula where wells used by a fish farm ittica ugento have shown high concentrations of hydrogen sulphide data from surface and boreholes stratigraphic surveys integrated with electrical resistivity tomography ert allow us to define the structure depths and geometry of the aquifer and its relationship with saltwater intrusion induced polarization ip with pole dipole array survey has been carried out near the coastline the value measured was over 50 msec a direct relationship is shown to exist between ip values and the aquifer containing sulphur water the high resolution of the data obtained with the applied methods not only shows the validity of the methodology but is the key to evaluating the groundwater resources of the area the proposed mechanism is that of entrapment of sulphur water in a graben structure when sulphate enriched waters of marine origin come into contact with organic substances and lignite deposits galatone formation oligocene they are deprived not only of free oxygen but also generate hydrogen sulphide as a result of the reduction of sulphates

understanding and modelling spatial drain aquifer interactions in a low lying coastal aquifer the thurne catchment norfolk uk seawater intrusion into fresh groundwater formations generally results inadvertently from human activities such as over abstraction from coastal aquifers this article describes the data analysis to quantify drain aquifer interactions in a low lying pump drained coastal aquifer which is subject to saline intrusion due to widespread land drainage and the resulting development and application of a numerical groundwater model to understand the spatial groundwater system behaviour including groundwater salinity fluxes without measured flow data in this pump drained catchment a novel groundwater head dependent approach to hydrograph separation is described time variant and time invariant modflow analyses are utilised to examine the flow processes a new approach to calculate drain coefficients which represent the extensive network of drainage ditches in the regional model using field information is described the sum of the drainage coefficients are close to the values independently estimated from the head dependent hydrograph separation results show that 1 the groundwater flows into the drainage systems are well reproduced using the new drain coefficients 2 particle tracking of fresh and saline water can explain observed spatial salinity distribution within drainage networks and 3 the modelled flow of seawater across the coast is approximately 25 greater than that discharged by the pumps demonstrating the need for drainage management to be aware of the slow response of groundwater systems to past drainage system changes the article demonstrates that numerical groundwater modelling can produce the improved understanding needed to inform management decisions in such complex environments copyright 2010 john wiley sons ltd

outflow patterns of pollutants from east asia to the north pacific in the winter monsoon outflow patterns of air pollutants and mechanisms associated with a monsoon condition that is peculiar to the east asian region in winter have been studied to capture the continental outflow airborne and shipboard measurements of aerosols and trace gases were conducted over the northern part of the east china sea and the western part of the sea of japan on january 17 26 1991 airborne january 28 29 1992 airborne january 22 31 1993 shipboard and january 29 30 1993 airborne at least two types of highly polluted air masses were found at different times of the monsoon type 1 polluted air mass which contained more than 10 g m 3 of non sea salt so 4 2 and more than 5 gc m 3 of black carbon aerosols typically appeared over the east china sea at the beginning of the monsoon period chemical and microphysical characteristics suggest that the type 1 polluted air mass is chemically aged type 2 air mass appeared in the later half of the monsoon period and had characteristics of freshly emitted pollutants it consisted of several high concentrations of so 2 10 ppbv confined in narrow horizontal width 10 to 30 km wide analyses using an eulerian chemical transport model and detailed backward trajectories indicate that the type 1 polluted air mass was subcontinental in extent and its formation and the transport were dominated by a synoptic scale weather cycle it was formed over the asian continent under anticyclonic conditions that persisted for 3 4 days and transported intermittently to the east over the pacific ocean by the passage and the development of traveling cyclones this study suggests that aerosols that flow out from east asia are enriched with carbonaceous materials and consequently have low single scattering albedo which may affect the direct radiative forcing by aerosols over the north pacific

karst geosites at risk of collapse the sinkholes at nociglia apulia se italy this paper focuses on the impacts of contemporary geomorphological processes on fruition activities in a karst area of salento apulia southeastern italy the work illustrates the results of studies in a sinkhole field at nociglia in the lecce province recently recognized as a geosite and where shallow phreatic speleogenesis operates close to the water table level with the formation of karst caves successive roof collapse formation of wide caverns and sinkhole development at the surface all these features threaten the nearby infrastructures including a province road salento has a great number of active sinkholes related to natural and anthropogenic cavities their presence is at the origin of several problems in the built up environment due to increasing population growth and development pressures in such a context the detection of cavities and the assessment of sinkhole hazards present numerous difficulties to assess the potential danger from sinkholes it is important to identify and monitor the main factors contributing to the formation process a multi disciplinary approach comprising geological geomorphological and geophysical analyses is necessary to obtain a comprehensive knowledge of these complex phenomena in karst areas geophysical methods can be of great help to monitor the processes and for identifying and mapping features related to the underground voids by detecting contrasts in physical properties such as density and electrical resistivity with the surrounding sediments at the same time recognition of the presence of sinkholes by geophysical methods has to adapt to the local geological conditions and take advantage of the integration of the several methodologies available the territory of nociglia demonstrates that monitoring is essential for the safe exploitation of these type of geomorphosites

groundwater flow modeling of quaternary aquifer ras sudr egypt recently ras sudr the delta of wadi sudr area received a great amount of attention due to different development expansion activities directed towards this area although quaternary aquifer is the most prospective aquifer in ras sudr area it has not yet completely evaluated the present work deals with the simulation of the quaternary groundwater system using a three dimensional groundwater flow model modflow code was applied for designing the model of the ras sudr area this is to recognize the groundwater potential as well as exploitation plan of the most prospective aquifer in the area the objectives were to determine the hydraulic parameters of the quaternary aquifer to estimate the recharge amount to the aquifer and to determine the hydrochemistry of groundwater in the aquifer during this work available data has been collected and some field investigation has been carried out groundwater flow model has been simulated using pilot points method seawat has been also applied to simulate the variable density flow and sea water intrusion from the west it can be concluded that 1 the direction of groundwater flow is from the east to the west 2 the aquifer system attains a small range of log transformed hydraulic conductivity it ranges between 3 05 and 3 35 m day 3 groundwater would be exploited by about 6 4 106 m3 year 4 the estimated recharge accounts for 3 106 m3 year 5 an estimated subsurface flow from the east accounts for 2 7 106 m3 year 6 the increase of total dissolved solids tds most likely due to dilution of salts along the movement way of groundwater from recharge area to discharge area in addition to a contribution of sea water intrusion from the west moreover it is worth to note that a part of tds increase might be through up coning from underlying more saline miocene sediments it is recommended that 1 any plan for increasing groundwater abstraction is unaffordable 2 reliable estimates of groundwater abstraction should be done and 3 automatic well control system should be made

coastal towers and historical sea level change along the salento coast southern apulia italy abstract the perimeter of salento peninsula southern apulia italy is studded by numerous coastal towers built in the xvi century aiming to create an early warning system against pirates attacks at present two of them fiumicelli tower on the adriatic coast and pali tower on the ionian one have bases a few decimeters below mean sea level the unusual position of both coastal towers can be explained by taking into account geomorphological features of the coastal area and the relative sea level change during the last 500 years geomorphological analysis reveals the occurrence directly in front of the two coastal towers of a wide rocky shore platform to about 1 m depth if a mean sea level about 0 6 1 0 m below present position is supposed at the time of coastal tower construction the wide shore platform would be slightly above sea level and would be able to protect the towers from sea storms furthermore by comparing these data with the results of available glacio hydro isostatic models for southern apulia during the late holocene it is possible to postulate tectonic subsidence of the salento coastal area during the last five centuries the collated data establish the quaternary tectonic history of salento peninsula it experienced a period of general subsidence during the lower pleistocene that was interrupted by rapid uplift during the middle pleistocene uplift stopped at mis 9 3 about 330 ka replaced by a phase of substantial stability which lasted until the late pleistocene holocene finally active tectonic subsidence has affected the coast of salento peninsula during the last four millennia probably in response to the recent doming of the region

a three dimensional miscible transport model for seawater intrusion in china a three dimensional miscible transport model for seawater intrusion in a phreatic aquifer with a transition zone is presented this model considers many important factors such as the effect of variable density on fluid flow the effect of precipitation infiltration and phreatic surface fluctuation on the process of seawater intrusion the existence of great discharge pumping wells etc the difficulty in solving this problem can be tackled by the presented numerical method and iteration technique this model is used to describe seawater intrusion in huangheying longkou people s republic of china the simulated values agree very well with the field data e g the total mean values of the absolute error of cl concentration are 46 13 mg l and 55 67 mg l respectively and those of the water head are 0 24 m and 0 08 m respectively

conceptualization and characterization of a coastal multi layered aquifer system in the taranto gulf southern italy in some mediterranean karst areas groundwater is often the only available supply for fresh water besides the contamination induced by human activities coastal aquifers often suffer from the saltwater intrusion phenomenon which can be enhanced by both extensive withdrawals and climatic changes establishing an effective set of regulatory and management measures to ensure the sustainability of coastal aquifers requires a deep knowledge about natural and anthropic stresses involved in groundwater dynamics in this regard a prior conceptualization of aquifer systems and a deeper characterization of balance terms through mathematical modeling are of paramount importance in this paper previous works on the three dimensional hydrostratigraphic characterization and two dimensional groundwater flow modeling at the regional scale for the salento peninsula southeastern italy are shown to provide a fundamental basis for an overall conceptualization of the multi layered aquifer system of the taranto gulf northwestern salento this is done by identifying source terms and providing a preliminary estimate of different balance terms based on available data and information then a further characterization will be provided using three dimensional groundwater flow models and calibration techniques based on the solution of an inverse problem as a result the hydraulic features of the deep karst aquifer can be mapped the stresses due to human water demanding activities and the occurrence of the saltwater intrusion phenomenon were analyzed and possible weaknesses of the conceptual and of the preliminary numerical model pointed out

karsys hydrogeological 3d modeling of alpine karst aquifers developed in geologically complex areas picos de europa national park spain karst aquifers are valuable groundwater resources whose management requires the use of functioning hydrogeological models the karsys approach provides an explicit 3d conceptual model of the geometry and the functioning of karst aquifers that has been successfully applied in swiss and slovenian aquifers in this work karsys is applied in a complex geological area the picos de europa national park spain the hydrogeological 3d model 500 km2 shows an alpine karst aquifer compartmentalized into 32 groundwater bodies dammed up by subvertical barriers creating elevated saturated zones water tables at 1153 m asl and lower ones water tables at 145 m asl the recharge is through 18 spring catchment areas the groundwater flows to the saturated zones pass through vertical to inclined trajectories and phreatic flows are oriented toward nw ne and n karsys can be applied to any geologically complex area at a regional scale although the geological structure should be simplified and the precision in some places is low nevertheless karsys helps to identify the hydrogeological behavior of karst areas and is a useful guide for future hydrogeological researches

sporadic transport and deposition of continental aerosols to the pacific ocean aerosol samples were collected in the surface air over the north pacific on board a vessel in may and june 1980 and were analyzed for na al fe mn and 210pb the results of the analysis of duplicate samples show good agreement the concentration ratios of fe al and mn al are similar to those of crustal material the concentration of al in the maritime surface air was usually observed to be 30 50 ng m3 on june 9 however an extremely high concentration of 670 ng m3 of al was observed at 30 n 161 e the al concentration is still insufficient to explain the accumulation rate of aluminosilicate in the pelagic sediment if the deposition velocity is 1 cm s but the nature of the kosa particles is possible to explain it even though the dust particles are sporadically transported although both al and 210pb are of continental origin the behavior of 210pb is somewhat different from that of al

monitoring and methods to analyse the groundwater quality degradation risk in coastal karstic aquifers apulia southern italy 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

speleogenesis in highly geodynamic contexts the quaternary evolution of monte corchia multi level karst system alpi apuane italy abstract the mt corchia karst system is one of the most important and famous caves in the world different from many other large caves here the geological structure has had only a minor role on the vertical multi level pattern of the cave a detailed geomorphic and morphometric analysis of the cave and a preliminary study of cave sediments along with new datings of speleothems allow us now to depict the multistage evolution of this cave which produced at least three major paleo phreatic levels related to different base level stages the analysis of the directions of cave passages shows that the three main phases have different orientations which can be attributed to the different surface morphology during speleogenesis in former times chronological constraints and geomorphic features suggest that the upper part of mt corchia cave developed during the end of pliocene in a stage of favourable climatic conditions and with a moderate tectonic uplift rate the morphological features and the nature of sediments in the upper paleo phreatic level at 1350 1450 m above present sea level apsl imply the occurrence of a wide allogenic catchment area this drainage pattern persisted also in the following stage during a significant but slow lowering of the base level which allowed the formation and the intense vadose rearrangement of the epi phreatic network around 1100 1250 m apsl an uplift stage in the early pleistocene caused the capture of the basins and the loss of allogenic feeding a third epi phreatic level was formed at around 900 m apsl when the catchment area was reduced to the present extent of carbonate rock more than 1 ma ago the recent evolution is due to rapid uplift and to the progressive incision of surrounding basins which led to the lowering of the local base level and to a readjustment of the cave system in order to adapt to a new equilibrium with the present elevation of the springs

karst groundwater resources in the countries of eastern mediterranean the example of lebanon the hydrogeological study of some karst systems in lebanon shows important storage capacity up to 27 billions m3 for zarka system the spring of orontes river their geological and morphological settings as well as their hydrodynamic function show structures developed below the level of present springs probably up to several hundreds meters at depth since miocene those carbonate formations were subject to a remarkable instability of their base levels variations of sea level of which the messinian salinity crisis is the major phase and effects of the alpine orogenesis combined with climate variations to develop complex multiphased karst systems karstification occurs frequently in the whole formation often deeply below sea level or underneath sediment filling of continental basins the surface karst landscape is often intensely eroded those multiple superimposed karst phases give the carbonate aquifers their large extension and storage capacity these karst aquifers show the typical easy restoration of storage they have the ability to bear large interannual recharge variations and support exploitation under high pumping rates however these aquifers have some disadvantages for sustainable management in some regions successful boreholes which allow high pumping rates also induce uncontrolled exploitation another consequence is natural seawater intrusion as well as the submarine discharge of fresh groundwater in coastal aquifers those carbonate aquifers are subject to important economical stress which jeopardizes their durability the systematic study and understanding of carbonate aquifers in eastern mediterranean is a preliminary condition to any integrated and sustainable management of water resources studies in progress in lebanon may serve as examples to the whole region

inverse modelling of seawater intrusion in the llobregat delta deep aquifer abstract a flow and mass transport mathematical model has been calibrated to simulate piezometric head and chloride evolution in the llobregat delta confined aquifer a twenty year period 1965 1985 is simulated with monthly time steps automatic estimation of flow and transport parameters are obtained by means of a code that simulates flow and mass transport of constant density fluids in this case density differences owing to groundwater salinity changes by marine intrusion can be neglected because the aquifer thickness is relatively small and because both the horizontal density gradient and the aquifer dip are small calibration of the flow problem leads to an excellent fit between measured and computed heads which however can be obtained with different transmissivity patterns when switching to the transport problem best results in terms of concentration fits are obtained by associating the seawater intrusion plumes with high transmissivity zones that can be attributed to palaeochannels in short transient head and concentration data have been used jointly for automatic calibration of a regional model which has proven advantageous both because it facilitates model selection and because it has led to a model with an improved conceptual basis