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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2010.02.025 Byline: J. Vias (a), B. Andreo (b), N. Ravbar (c), H. Hotzl (d) Abstract: The vulnerability of four European aquifers with different hydrogeological and climatic characteristics was evaluated using the COP method. The results obtained were statistically analyzed by determination coefficients to measure which factor has greater importance in the vulnerability index. Furthermore, a new parameter has been designed to measure the vulnerability for the whole of the aquifer. The results demonstrate that COP is a useful method to assess the vulnerability of the test sites under consideration. The results obtained are coherent with the conceptual model of each pilot aquifer and the available hydrogeological information (hydrographs, isotopic data, tracer tests). Fissured carbonate aquifers (diffuse flow systems) are less vulnerable than karst aquifers (conduit flow systems) and the vulnerability index is more positively correlated with the O factor (unsaturated zone protection capacity) in the first case. The karst aquifers are more vulnerable than fissured aquifers and they show a higher correlation between the C factor (karst features) and the vulnerability index. Climatic variation (precipitation for example) influences the final vulnerability index of the aquifers according to the weight in the index and the spatial distribution. Author Affiliation: (a) Department of Geography, University of Malaga, E-29071 Malaga, Spain (b) Department of Geology and Centre of Hydrogeology, University of Malaga, E-29071 Malaga, Spain (c) Karst Research Institute, Postojna, Slovenia (d) Department of Applied Geology, University of Karlsruhe, KaiserstraAe 12, D-76128 Karlsruhe, Germany Article History: Received 7 October 2008; Revised 2 February 2010; Accepted 15 February 2010

Protection zoning of karst springs and wells used for water supply is a key aspect in many countries, calling for specific methodologies adapted to the particular characteristics of karst media. This work presents a new approach, in view of the present state of the art and based on experiences with contamination vulnerability mapping at the pilot site of the Villanueva del Rosario karst system (southern Spain). Source (intrinsic) vulnerability maps were prepared and compared using three European procedures for karst aquifers. The vulnerability maps were then tested using dye tracers. The COP + K method and Slovene Approach appear to provide reliable results in terms of intrinsic vulnerability mapping. Nevertheless, all the methods have a margin of error. The COP + K map is adopted as the baseline to delineate the protection zones, through the conversion from vulnerability classes to degrees of protection. [ABSTRACT FROM AUTHOR]

Abstract: From analysis of spectrophotometric properties of dissolved organic matter (OM) and the hydrochemical responses of some karst springs under different hydrologic conditions, an assessment of the origin and transfer pathway of OM present in karst spring waters, from soil and epikarst toward the spring, has been conducted for three karst aquifers in southern Spain: Alta Cadena, Sierra de Enmedio and Los Tajos. Intrinsic fluorescence (excitation–emission matrices or EEMs), together with major water chemistry (electrical conductivity, temperature, alkalinity, Cl−, Mg+2) and PCO2 along with natural hydrochemical tracers (TOC and NO3 −), have been monitored in 19 springs which drain the three karst aquifers examined in this study. The spring water EEM spectra indicate that fulvic acid-like substances, produced in the soil as a consequence of the decomposition of OM, are the dominant fluorophores, although some of the OM appears to originate from in situ microbiological activity but could be indicative of contamination present in recharge waters from livestock. During each recharge event, TOC and NO3 − concentrations increased and variations in fluorescence intensities of peaks attributed to fulvic acid-like compounds were observed. In areas with minimal soil development, spatial and temporal variations in the fluorescence intensity of fulvic acid-like substances and other fluorophores derived from microbiological activity, together with other hydrochemical parameters, provide insights into the hydrogeological functioning of karst aquifers and the infiltration velocity of water from soil and facilitate assessment of contamination vulnerability in these aquifers. [Copyright &y& Elsevier]

The isotopic composition (18O and 2H) of rainwater and groundwater was determined in the Yunquera-Nieves hydrogeological unit, a karstic massif in S Spain with complex orography and hydrogeology. The aims were to identify: (1) the source of the water, (2) the main factors determining the isotopic content, (3) the catchment area of the springs and (4) the aquifer behaviour. The isotopic content of the sampled waters is of mixed Atlantic–Mediterranean origin and is opposite to the quantity of rainwater distribution, both in space and time. Spatially, water is isotopically less depleted toward the eastern sector, where rainwater quantity is lower (which is locally affected by the orography): thus, it is possible to differentiate the catchment areas of the main springs. Aquifer recharge is produced by winter precipitation, when rainfall water is isotopically more negative and evaporation is lower. The decrease in rainfall quantity during the study period provoked an increase in δ18O and δ2H values, both in rainwater and in groundwater. The recorded variations of the isotopic content of the rainfall are rapidly evident in the spring waters, which demonstrates a well developed karst network inside the carbonate aquifers, and thus the existence of conduit flow systems. [Copyright &y& Elsevier]

In order to treat and evaluate the available data of water quality and fully exploit monitoring results (e.g. characterize regional patterns, optimize monitoring networks, infer conditions at unmonitored locations, etc.), it is crucial to develop improved and efficient methodologies. Accordingly, estimation of water quality along fluvial ecosystems is a frequent task in environment studies. In this work, a particular case of this problem is examined, namely, the estimation of water quality along a main stem of a large basin (where most anthropic activity takes place), from observational data measured along this river channel. We adapted topological kriging to this case, where each watershed contains all the watersheds of the upstream observed data (“nested support effect”). Data analysis was additionally extended by taking into account the upstream distance to the closest contamination hotspot as an external drift. We propose choosing the best estimation method by cross-validation. The methodological approach in spatial variability modeling may be used for optimizing the water quality monitoring of a given watercourse. The methodology presented is applied to 28 water quality variables measured along the Santiago River in Western Mexico. [ABSTRACT FROM AUTHOR]

In detrital coastal aquifers, seawater and surface water may interact with groundwater in multiple ways. Understanding the interference of water fluxes in this type of environment is essential to effectively manage the groundwater resources in water-stressed regions, such as the Mediterranean coastal fringe. In this research, the characterization of the main hydrogeochemical processes and the interaction between surface water and groundwater in the Marbella-Estepona coastal aquifers (southern Spain) have been carried out by means of the combined use of different hydrogeochemical indicators along with isotope data. The results show that the diversity of source lithologies (peridotite, carbonate and/or metapelitic) substantially conditions the groundwater geochemistry. The analysis of ionic deltas made it possible a preliminary screening of the geochemical reactions that occur in the Marbella-Estepona aquifers, while the Discriminant Analysis allowed for a consistent classification of sampled groundwater types. The dissolution of calcite and dolomite determines the chemical composition of the groundwater from the eastern sector that are more conditioned by the rainwater infiltration. The dissolution of magnesium-bearing minerals (predominantly forming peridotite rocks) is observed in groundwater samples from the western and central sectors, whose chemical composition showed a greater influence of surface water. The spatial analysis of rCl − /Br − in groundwater has permitted to corroborate that saline intrusion is negligible, hardly affecting to its original water quality. The irregularly distributed recharge by precipitation (seasonal effect) and the atmospheric circulation of cloud fronts (coastal/continental effect) explains why most of groundwater sampled is isotopically impoverished with respect to the rainfall signature. The isotope approach also suggests the hydraulic relationship between surface water and groundwater in the study site. A deeper knowledge of spatial hydrogeochemical variations in coastal groundwater and the influence of water sources over them are crucial for a sustainable groundwater management and global change adaptation in equivalent Mediterranean water-stressed regions. [ABSTRACT FROM AUTHOR]

• Hydro-environmental changes in an anthropized river mouth (S Spain) were studied. • Surface water and groundwater dynamics have been modified after river channelization. • Land use change has an important influence on hydrologic regime. • Wetlands salinization has been driven by the diversion of groundwater flows. • Bird species abundance and diversity vary depending on the water quality. The Guadalhorce River mouth (Málaga, Southern Spain) was channelized between 1997 and 2003 to reduce flooding potential in adjacent densely populated sections of Málaga. The channel was bifurcated near the Mediterranean Sea, surrounding an isolated wetland complex composed of eight different ponds. Groundwater-level and wetland-stage data, combined with water-chemistry data from wells and wetlands, collected since 1977, have documented the hydrological and ecological responses to channelization. The results show that channelization has extended the tidal influence inland from the Mediterranean Sea through the Guadalhorce River and the subjacent coastal aquifers, producing a change in groundwater hydrodynamics. The isolation of the wetlands resulting from channelization has provoked a significant salinization of both surface water and groundwater, the extent of which varies among wetlands. These decadal-scale changes in water chemistry have promoted the appearance or increase of halophilic vegetation and have caused a shift from diving birds to predominantly shorebirds in some wetlands. Documentation of these unexpected ecosystem responses is a necessary first step for land managers who need to consider groundwater and surface water as a single resource, particularly in groundwater-dependent ecosystems along the densely populated and ecologically sensitive Mediterranean coastal areas. [ABSTRACT FROM AUTHOR]