GIS-Based Assessment for the Development of a Groundwater Quality Index Towards Sustainable Aquifer Management

This study aims at developing Groundwater Quality Indices (GQIs) that constitute a reliable tool in defining aquifer vulnerability. For this purpose, water quality sampling campaigns were conducted on 60 groundwater wells during most vulnerable periods of early and late summer to ensure the representativeness of the targeted GQI under worst case conditions. The samples were tested for various water quality indicators, which were then used to develop the GQIs through GIS-based mapping with spatial geostatistical analysis. The results contribute in filling a gap in GQI definition and form a basis for planning effective water quality management towards sustainable exploitation of groundwater resources particularly during summer periods when recharge is limited.     

Aquifers Overexploitation in SE Spain: A Proposal for the Integrated Analysis of Water Management

Integrated water resources management is a paradigm that incorporates technical, scientific, political, legislative and organizational aspects of a water system. This study presents a methodology for undertaking an integrated analysis of water systems supplied by groundwater. This methodology is here applied to examine the water system of the Altiplano region in Murcia, where the water extraction from the aquifers greatly exceeds recharge and the irrigated areas supplied by those aquifers have a very high agrarian profitability. First, the hydrological problematic of the case study was conceptualized. Then, a sectorial study on each aspect related to the water management of the system was developed. As Bayesian Networks was the chosen technique for the integrated analysis, the information obtained by the sectorial studies was translated into specific variables, which together with the relations among them, modelled the real situation. As from a hydrogeological point of view the water system is comprised of four autonomous aquifers, a Bayesian Network for every aquifer was designed. This decision-support system enables us to evaluate the impacts generated under diverse water management scenarios.     

An Artificial Intelligence Approach for the Stochastic Management of Coastal Aquifers

Aquifer recharge rates and patterns are often uncertain, especially in arid areas due to sporadic and erratic rainfall. Therefore, determining the optimal groundwater abstraction using classical approaches such as Monte Carlo Simulation (MCS) requires a large number of groundwater simulations and exorbitant computational efforts. The problem becomes even more complex and time consuming for regional coastal aquifers whose domains must be discretized using high-resolution meshes. In fact, even fast evolutionary multi-objective optimization techniques generally require a large number of simulations to determine the Pareto-front among the objectives. This study explores the performance of a Decision Tree (DT) approach for the generation of the Pareto optimal solutions of groundwater extraction. This paper applies the DTs for the optimal management of the Al-Khoud coastal aquifer in Oman. The learning process of the developed DT-based model uses the output of a numerical simulation model to assess the aquifer response based on different abstraction policies. The trained DT network then utilizes the NSGA-II to determine the Pareto-optimal solutions. The simulation show that the general flux pattern in the study area is toward the sea and the hydraulic head following a similar pattern in both best and worst recharging scenarios downstream of the studied recharging dam. Statistical tests showed a good correlation between the DT-based and simulation-based results and demonstrate the capability of the DT approach to obtain high-quality solutions by incorporating a large number of recharge scenarios. Moreover, the required runtime of the DT-based approach is extremely low (5 min) compared to that of the simulation-based method (several days). This means that including additional Monte-Carlo simulations can be readily done in few minutes using the obtained DTs, instead of the long computational time needed by the simulation-based approach.     

An Integrated DSS for Groundwater Management Based on Remote Sensing. The Case of a Semi-arid Aquifer in Morocco

A Decision Support System has been set up as the result of a fruitful cooperation between several public and research institutions in the framework of a large cooperation program. The DSS aims to compare spatially and temporally sectorial water demands of the Haouz-Mejjate plain (Morocco) in regard to available surface and groundwater resources. It is composed of a tool for satellite estimation of Agricultural Water Demand (SAMIR), a tool for integrated water resources planning (WEAP) and a groundwater model (MODFLOW) each of them relying on a common Geographical Information System not described here. The DSS is operating on a monthly time scale. Agricultural water demand accounts for about 80?% of the total demand. In areas where groundwater abstraction is difficult to quantify by direct methods, multitemporal remote sensing associated to the FAO methodology is a simple and efficient alternative to estimate Evapotranspiration (ET). In this work, a monthly estimate of ET from irrigated areas is derived from freely available MODIS NDVI for the 2001?C2009 period. An important part of the paper deals with the validation of these estimates with eddy covariance flux measurements installed on different irrigated crops of the region. Results are satisfactory with a minus 6.5?% error per year on the monthly time scale. This preprocessing allows to dichotomize irrigated versus non-irrigated areas, and then, to estimate groundwater abstraction in subareas distinguishing by their operating modes: traditional, dam or privately irrigated. A dynamic linkage between MODFLOW and WEAP transfers the results of one model as input data to the other. The model restitutes both spatial and temporal variations in head charges and allows the calculation of the ground water balance. After calibration, piezometric validation is acceptable for the majority of the 21 head control points.     

An Indicator Based Assessment for Water Resources Management in Gediz River Basin,Turkey

In this study, a water resources management model that facilitates indicator-based decisions with respect to environmental, social and economic dimensions is developed for the Gediz River Basin in Turkey. The basic input of the proposed model is the quantity of surface water that is greatly allocated to irrigation purposes; therefore, supply and demand interrelations in agricultural water use constitute the main focus of the study. The model has been applied under three different hydro-meteorological scenarios that reflect baseline as well as better and worse conditions of water supply and demand, not only to reach an assessment of water budget, but also to evaluate the impacts of proposed management alternatives under different conditions. The Water Evaluation and Planning (WEAP) software is used as a simulation and evaluation tool to assess the performance of possible management alternatives, which is measured by nine proposed indicators. The results of the study have indicated that the Gediz River Basin is quite sensitive to drought conditions, and the agricultural sector is significantly affected by irrigation deficits that increase sharply in drought periods. Even if the optimistic scenario is assumed to occur, it is not possible to observe a significant improvement in the water budget; however, the negative impacts of climate change can possibly exacerbate the water crisis. The indicators also verified that, efficient water management is crucial to ensure the sustainable use of water resources with respect to environmental, social and economic dimensions.     

Rapid Sediment Assessment: Indicator Analysis and Screening Analysis Approaches

Efficiently characterizing the distribution of contaminated and toxic sediments in rivers and harbors is usually limited by the expense of conventional chemical and toxicological analyses. Two approaches were developed to address this problem; the indicator analysis approach, used in the ARCS project, and the screening analysis approach, here applied to a sediment assessment project on the Ottawa River (Toledo, Ohio). The indicator analysis approach utilized two suites of analyses; 23 conventional toxicological and chemical analyses performed on a subset of samples, and 11 rapid, inexpensive chemical and toxicological assays performed on many samples, including those analyzed using the conventional analyses. Predictive correlation equations were generated using step-wise linear regression, and these equations were used to calculate values for the conventional analyses for samples on which they were not performed. This approach generated statistically strong predictive equations, as well as a “weight of evidence” data set useful for evaluating relative sediment contamination. The equations, however, were very site-specific, and sometimes contained terms which were counter-intuitive, and the approach failed if the data sets contained too many “non-detect” or 100% mortality values. The screening analysis approach measured total PCBs by enzyme immunoassay (EIA) and 18 elements by x-ray fluorescence spectroscopy (XRF). These analyses correlated very strongly with gas chromatography (GC) and atomic absorption spectroscopy (AA), respectively, and their production rates and costs were far superior. A low bias was observed in the EIA data, compared to the GC data, possibly due to inefficient EIA extraction of the oily sediments, or to a mismatch between the PCB mixtures in the sediment and used as a calibrator for the EIA. XRF data for Cr, Cu, Mn, Ni, Sb, and Zn exhibited a positive bias compared to AA, while Cd and Pb did not. This was probably due to metal-specific variations in the contribution of mineral matrix-associated metal to the acid-digestible metal quantified by AA. Both EIA and XRF can be performed in the field, to produce near-real time data to guide sampling. Detection limits of the PCB EIA (0.12 μg/g DW) and of XRF (typically 5 to 15 μg/g DW) are adequate for most sediment assessment projects. Of the two approaches, screening analyses are recommended for the rapid, cost-effective characterization of contaminated sediments.     

Integrated Assessment of the European WFD Implementation in Extremely Overexploited Aquifers Through Participatory Modelling

Participatory methods provide an increasingly accepted path to integrated water assessment. This research describes an interdisciplinary exercise of scenario design and modelling, which provides a methodology to couple hard science numerical modelling approaches with the involvement of key water actors and socioeconomic issues. A decision support system based on probabilistic methods (Bayesian networks) is the tool chosen for dealing with the interdisciplinary issues involved in this aquifer. Given the long-standing conflicts in the area, modelling work largely focuses on carrying out an impact assessment produced by different scenarios established under the light of the mandatory objectives established by the European Union Water Framework Directive. This methodology is applied to a semi-arid aquifer located in SE Spain (Serral-Salinas) that represents an extreme case of intensive groundwater use. Irrigation has been a catalyst for welfare in the area for the past 40?years, despite the resulting large groundwater drawdown and continuous rise of groundwater pumping energy costs. Modelling results suggest that only a drastic change in the abstraction regime can produce a solution to long term sustainability of the aquifers. In addition, the impact assessment advises that such objectives are unlikely to be met due to the high economic costs of this action.     

Sustainable Management for Minimizing Land Subsidence of an Over-Pumped Volcanic Aquifer System: Tools for Policy Design

Groundwater management scenarios for the Toluca Valley, Mexico, are examined with a three dimensional groundwater flow model coupled to a one dimensional compaction module. The objective of this study is to establish a management policy for the sustainable development and management of the Toluca aquifer system for minimizing land subsidence. Several scenarios are tested by varying 4 main parameters: recharge, exports to other basins, local consumption, and relocating pumping centers. It is apparent that continuing at current rates of water consumption will lead to subsidence of more than 1.6 m over a 40 year period (2010–2050). Completely stopping exports to Mexico City is not the most important factor in controlling subsidence because the pumping system is mostly located in regions with low clay content, where subsidence is lower. However, decreasing exports by half and relocating the pumping centres to low-clay-content areas does have a positive effect on the overall water budget and subsidence. Based on simulation results, it appears that much of the land subsidence could have been avoided had water policies been applied to restrict pumping in regions with compressible materials. The approach taken in this study could be applied to other locations with similar problems in order to determine the most viable option for water supply.     

水资源统一管理与可持续利用

水资源的资源特性、流域特性、功能特性，服务特性决定了水资源必须进行统一管理，水资源统一管理的实质是为了在保障水资源可持续利用的基础上，实现水资源综合开发、优化配置，高效利用和有效保护的科学组合和最佳的经济、社会和生态效益，统筹安排好生活、生产、生态三的用水，保障人口、资源、环境和经济的协调发展，为国民经济和社会发展的各项项目标和任务提供支撑和保障。     

An Economic Analysis of Integrated Fisheries Management: The Case of the Lake Michigan Alewife and Salmonid Fisheries

Intense predator-prey relationships exist between stocks of alewives and salmonids in Lake Michigan. In this paper, the economic implications of these biological interactions are explored and suggestions regarding efficient fisheries management options are made. A theoretical optimal control model is developed which delineates conditions for optimizing alewife and salmonid harvest rates. Model results indicate that the indirect effects which harvesting in one fishery have on harvest costs and returns in the other must be considered if economic efficiency in alewife/salmonid management is to be achieved. Furthermore, marginal net social values associated with alewife and salmonid harvests must be equated. It is estimated that alewives currently have a marginal net social value close to zero compared to $4.10 per salmonid. These findings strongly suggest that utilization of alewife biomass as a forage base for predatory salmonids is more efficient than direct harvesting of alewives in a commercial fishery.     

Development a Novel Integrated Distributed Multi-objective Simulation-optimization Model for Coastal Aquifers Management Using NSGA-II and GMS Models

Water Resources Management - Groundwater is one of the most valuable water resources in the world in terms of quantity and quality. Therefore, their protection as an important issue should be...     

Modelling the Effects of Groundwater-Based Urban Supply in Low-Permeability Aquifers: Application to the Madrid Aquifer, Spain

The European Union Water Framework Directive establishes the obligation to all Member States to develop and implement catchment-scale management plans. These aim at reaching a good status of all water bodies in Member States by 2015 or, at the latest, by 2027. Numerical models provide a suitable approach to evaluate the possibilities of achieving this goal by enabling users to deal with complex hydrological interrelations in a dynamic manner. This paper presents a modelling-based approach to examine the past and future effects of groundwater-based urban supply in Metropolitan Madrid, Spain. Monthly scale model calibration is based on 32 years of water table observations. Care is taken to address the effect of intensive pumping on groundwater levels and streamflows, as well as the role of groundwater resources in meeting urban demands during dry spells. The paper concludes by reflecting on the implications and probabilities of meeting the aforementioned deadlines, as well as on the sustainability of past and future pumping trends. Policy considerations aside, modelling results suggest that groundwater extractions could be augmented considerably without causing a significant decrease in streamflows.     

An Integrated Indicator Based on Basin Hydrology,Environment, Life,and Policy: The Watershed Sustainability Index

Several issues impact the water sustainability of a river basin. Among them are the social, economic, and environmental aspects. However, they are often treated separately, and not as an integrated, dynamic process. In order to integrate the hydrologic, environmental, life and policy issues, as well as the existing pressures and policy responses in one quantitative, dynamic, and aggregated indicator, a watershed sustainability index (WSI), which uses a pressure–state–response function, was developed and is proposed in this paper. Applied to a 2,200 km² Unesco–HELP demonstration basin in Brazil (SF Verdadeiro), the value obtained for WSI was 0.65, which represents an intermediate level of basin sustainability.     

Integrated Approach for Supporting Sustainable Water Resources Management of Irrigation Based on the WEFN Framework

Irrigated agriculture plays a vital role for the socio-economic development of the Mediterranean area, although it has significant impacts on both water and energy resources. Therefore, in a context in which water resources are also experiencing increasing pressures, there is an urgent need for supporting their sustainable management. This may be an extremely challenging task, especially at the local scale, due to the several interconnected dynamics affecting the state of a complex irrigation system. In fact, multiple actors are involved in decision-making processes, and the use of natural resources (and their mutual interactions) strongly depends on their behaviors, which affect the system as a whole. In this context, the present study proposes an integrated methodology, based on the Water Energy Food Nexus (WEFN), specifically focused on the sustainable management of water resources for irrigation. Firstly, a model based on Causal Loop Diagrams (CLD) is developed in order to get a deep insight into the key dynamics behind a complex irrigation system. Secondly, three indices based on the “footprint” concept are identified, in order to synthesize such dynamics. The integration of these two approaches support investigating the whole system and, particularly, understanding the influence of multiple decisional actors on it, as well as the role of a set of key drivers and constraints. This might also allow drawing some relevant conclusions, useful for supporting effective decisions oriented to a sustainable water resources management. Specific reference is made to a case study, the Capitanata irrigation system, located in the Southern Italy.

     

A New Approach for Aquifer Vulnerability Assessment: the Case Study of Campania Plain

We are going to propose a new method for aquifer vulnerability assessment, named Susceptibility Index-Contamination Degree (SICODE). Starting from the assumption that soil chemistry impacts on infiltration water quality, geochemical tool such as the soil contamination degree index (CD) was combined with hydrogeological parameters in order to enhance previous well-known index (DRASTIC, Susceptibility Index). The study has been carried out at the Campania Plain (CP) aquifer, which mostly supplies the drinking water distribution system of Napoli (Southern Italy). The survey area extends from Mt. Vesuvius to the metropolitan area of Napoli and it can be considered an interesting field laboratory in order to test hydro-geochemical methods and models since both diffuse anthropogenic pollution and natural contamination sources (e.g. interaction processes between groundwater and rock) coexist. Three models have been compared. Our results have showed that DRASTIC is not the best model to be applied to urbanized environments since it does not account for the anthropogenic influence. Susceptibility Index (SI), which incorporates land use parameter, has showed a more detailed map of vulnerability degree and it better answers the local variability of human pressure. However, the proposed SICODE method completely meets the geochemical fingerprint of soil. Sensitivity analysis has revealed a high variability of the parameters due to the local heterogeneity of the analyzed system conditions. A comparison between the groundwater nitrates distribution and the predicted vulnerability has showed that. SICODE gave more accurate predictions than the other ones. This study has provided the evidence that combining hydrogeological and geochemical tools may enhance aquifer vulnerability assessment.

     

Integrated Hydro-Economic Modeling for Sustainable Water Resources Management in Data-Scarce Areas: The Case of Lake Karla Watershed in Greece

Water Resources Management - Hydro-economic models can serve as valuable tools to improve the understanding of system details, as well as to support decision-making and water resources management....     

An Operational Model for Support of Integrated Watershed Management

This paper presents a computer simulation-based methodology for operational support of integrated water resources management. The methodology is based on the systems approach, and use of feedback to capture physical and socio-economic processes occurring within a watershed. The approach integrates well established simulation models of physical processes with simulation models that describe socio-economic processes. The proposed methodology is illustrated by the evaluation of risk and vulnerability to changing climatic and socio-economic conditions in the Upper Thames watershed (south-western Ontario, Canada).The model results indicate that flooding in the watershed will be more severe as a result of climate change, while low flows are expected to remain at their current level. The most significant socio-economic factor in the Upper Thames watershed is water availability, shown to become under climate change a limiting factor for future growth and development.     

Assessment of the Contributions of Traditional Qanats in Sustainable Water Resources Management

Qanats (Kanats) have been an ancient, sustainable system facilitating the harvesting of water for centuries in Iran, and more than 34 additional countries of the world. These subterranean channels have been used for the transference of snowmelt water from the mountainous terrain for thousands of years. Agricultural, industrial and urban demands for fresh water have brought about increasing demands for water, the elixir of life. In response, the harvesting of water via deep groundwater wells throughout arid zones has disturbed the aquifers, and resulted in the abandonment of some qanats. Qanats in the province of Yazd City are witnessing this depletion. This paper introduces qanats, objectives causing their creation, construction materials, locations and their importance in different times, as well as their present role in Iran. Further, current qualitative and quantitative analyses of the qanats in Tehran are identified.     

Analysis and Assessment of Hydrochemical Characteristics of Maragheh-Bonab Plain Aquifer,Northwest of Iran

The present study aims at assessing the hydrochemistry of the groundwater system of the Maragheh-Bonab Plain located in the East Azarbaijan Province, northwest of Iran. The groundwater is used mainly for drinking, agriculture and industry. The study also discusses the issue of the industrial untreated wastewater discharge to the Plain aquifer that is a high Ca-Cl water type with TDS value of about 150 g/L. The hydrogeochemical study is conducted by collecting and analyzing the groundwater samples from July and September of 2013. The studied system contains three major groundwater types, namely Ca–Mg–HCO₃, Na–Cl, and non-dominant water, based on the analysis of the major ions. The main processes contributing to chemical compositions in the groundwater are the dissolution along the flow path, dedolomitisation, ion exchange reactions, and the mixing with wastewater. According to the computed water quality index (WQI) ranging from 25.45 to 194.35, the groundwater in the plain can be categorized into “excellent water”, “good water”, and “poor water”. There is a resemblance between the spatial distribution of the WQI and hydrochemical water types in the Piper diagram. The “excellent” quality water broadly coincides with the Ca-Mg-HCO₃ water type. The “poor” water matches with the Na–Cl water type, and the “good” quality water coincides with blended water. The results indicate that this aquifer suffers from intense human activities which are forcing the aquifer into a critical condition.     

Management of Alluvial Aquifers in Two Southern African Ephemeral Rivers: Implications for IWRM

This paper summarises innovative research into the assessment of long-term groundwater recharge from flood events in dryland environments of the Kuiseb (Namibia) and the Buffels (South Africa) rivers. The integrated water resource management (IWRM) policies and institutions affecting the exploitation of groundwater resources in each of these developing countries are compared. The relatively large alluvial aquifer of the Kuiseb River (～240 Mm³) is recharged from irregular floods originating in the upper catchment. Reported abstraction of 4.6 Mm³ per year is primarily consumed in the town of Walvis Bay, although the groundwater decay (pumping and natural losses along the period 1983–2005) was estimated in 14.8 Mm³ per year. Recharge is variable, occurring in 11 out of 13 years in the middle Kuiseb River, but only in 11 out of 28 years in the middle-lower reaches. In contrast, the Buffels River has relatively minor alluvial aquifers (～11 Mm³) and recharge sources derive from both lateral subsurface flow and floodwater infiltration, the latter limited to a recharge maximum of 1.3 Mm³ during floods occurring once every four years. Current abstractions to supply the adjacent rural population and a few small-scale, irrigated commercial farms are 0.15 Mm³ yr^???1, well within the long-term sustainable yield estimated to be 0.7 Mm³ yr^???1. Since independence in 1990, Namibia’s water resource management approach has focussed on ephemeral river basin management of which the Kuiseb Basin Management Committee (KBMC) is a model. Here, some water points are managed independently by rural communities through committees while the national bulk water supplier provides for Walvis Bay Municipality from the lower aquifers. This provides a sense of local ownership through local participation between government, NGOs and CBOs (community-based organisations) in the planning and implementation of IWRM. Despite the potential for water resource development in the lower Buffels River, the scope for implementing IWRM is limited not only by the small aquifer size, but also because basin management in South Africa is considered only in the context of perennial rivers. Since 2001, water service delivery in the Buffels River catchment has become the responsibility of two newly created local municipalities. As municipal government gains experience, skills and capacity, its ability to respond to local needs related to water service delivery will be accomplished through local participation in the design and implementation of annual ‘integrated development plans’. These two case studies demonstrate that a variety of IWRM strategies in the drylands of developing countries are appropriate depending on scales of governance, evolving policy frameworks, scales of need and limitations inherent in the hydrological processes of groundwater resources.