Multiobjective management of a contaminated aquifer for agricultural use

Planned utilization of groundwater from a contaminated aquifer requires development of management strategies that determine the spatial distribution of withdrawal for allocation, as well as for control of water quality. Minimization of groundwater allocation for different purposes, and the control of contamination in the aquifer by a specified pumping strategy constitute a management problem with two conflicting objectives. In order to demonstrate possible tradeoffs between water quality control objective and minimum groundwater withdrawal objective, a multiobjective optimization model is formulated. The solution of the model specifies a strategy to control pollution distribution in the aquifer as per agricultural needs, and also evolve an optimal allocation policy to statisfy agricultural demands. Pareto-optimal solutions representing the tradeoff between the two noncommensurate objectives are established. The formulated model uses the embedding technique for simulating the flow and the transport processes in the aquifer. The constraint method is used to transform the multiobjective optimization model into a single objective optimization model. The resulting model is solved using the exterior penalty function method in conjunction with the Hooke-Jeeves method. The proposed model is easily adoptable for various agroclimatic regions and cropping patterns. For illustrative purposes, the model is applied to a specified study area. Although solutions of the model are presented and discussed as per agricultural requirements in terms of both quality and quantity, solutions for other kinds of water demands can be obtained using the same model with minor modifications. Results show that an optimal pumping strategy can be effectively utilized for controlling contamination in the aquifer.     

A dimensionless analysis in the optimal management of groundwater pollutant sources

The impact of optimal waste disposal patterns upon the maximum assimilative capacity of groundwater systems is investigated in cases where the simultaneous utilization of the same aquifer for water supply as well as for waste disposal is required. A groundwater quality management model that combines analytic solutions off the dimensionless advective-dispersive transport equation with linear programming is developed. Three different patterns of waste disposal are considered: a constant rate, a pulsing-type, and a continuously varying rate. Optimal schedules for all the patterns are determined for a wide range of the problem's parameters, and a critical evaluation of their benefits leads, eventually, to a complete series of useful guidelines. These guidelines can serve as a-priori criteria for the selection of the most suitable waste disposal patterns.     

Pre-posterior analysis as a tool for data evaluation: Application to aquifer contamination

This paper deals with the frequently encountered problem of pre-posterior data evaluation, i.e., assessment of the value of data before they become available. The role of data is to reduced the risk associated with decisions taken under conditions of uncertainty. However, while the inclusion of relevant data reduces risk, data acquisition involves cost, and there is thus an optimal level beyond which any addition of data has a negative net benefit. The Bayesian approach is applied to construct a method for updating decisions and evaluating the anticipated reduction in risk following consideration of additional data. The methodology is demonstrated on a problem of management of an aquifer under threat of contamination.Notation L matrix of losses for all combinations of states and decisions - l, m, h possible salinity levels from the proposed borehole - N, M, F possible decisions - P(·) vector of prior probabilities of states - P(.|l), P(.|m), P(.|h) conditional (updated) probability vectors of the different states given the salinity levels - P(.|), P(.|), P(.|) probability vectors of the different salinity levels given the true states (likelihood function) - P(l), P(m), P(h) probabilities of the salinity levels, irrespective of the true state - R(.|l), R(.|m), R(.|h) posterior risk vectors of the different decisions given the salinity levels - R(N), R(M), R(F) prior risk associated with different decisions - , , possible true states     

Management of a multilayered Coastal aquifer — An Israeli case study

Intensive use of the Coastal Plain aquifer in Israel, as well as its ongoing contamination by agrochemicals and domestic and industrial waste, has resulted in the deterioration of its water quality. As a result, suggestions of abandoning this aquifer, which is a major source of potable water, have been seriously considered. The Coastal Plain aquifer is divided into a number of calcareous sandstone units separated by continental and marine lenses composed of silt and shale. Whereas the uppermost units are unconfined and are recharged directly from land suface by precipitation, wastewater, and runoff, the lower aquifers are partly confined. Although the presence of subaquifers is geologically well documented, the aquifer has been traditionally managed as a single water reservoir. The prevailing notion has been that the separation into subunits exists only up to 5 km from the shoreline, whereas, in the east, the aquifer is considered unlayered and uniform. However, hydraulic data, isotopic age determinations and variations in chemical composition, suggest that the clay lenses form an effective hydraulic partition between the different sand units, both in the western and eastern parts of the aquifer. The results of this study indicate that the prevailing conceptualization of the aquifer as one homogeneous water body is incorrect.     

参数化绘图在渡槽结构优化设计中的应用

在大型预应力U型渡槽结构优化设计中,需要将优化设计结果实现自动化绘图. 为解决这一问题,提出了将高级程序语言与AutoLISP相结合以实现参数化绘图的方法,开发了FORTRAN与AutoLISP混合编程程序设计系统.并将此程序设计系统运用于大型预应力U型渡槽槽身断面的优化设计过程中,把优化设计结果方便地转变成了形象直观的图形(文件),从而实现了自动化绘图.     

Flow and transport modelling of a highly stressed aquifer to refine management strategies

Overexploitation of groundwater in the eastern part of San Jacinto Watershed Basin in conjunction with reservoir leakage in the western part has reversed the groundwater flow direction and has caused migration of groundwater with high total dissolved solids (TDS) into an area of better-quality groundwater. The regional groundwater flow and transport model presented here shows how decreased pumping and artificial recharge in the east and extraction of high-TDS groundwater in the west can impact the area.     

青岛市地下水源地水质评价及污染原因分析

在对青岛市18处地下饮用水源地调查资料研究的基础上,分析了地下水源地的水质状况。结果显示,有9处水源地水质达到地下水Ⅲ类标准,9处水源地水质超出地下水Ⅲ类标准,表明了青岛市地下饮用水源地的污染已经相当严重。调查水源地普遍存在硝酸盐、总硬度、溶解性总固体的污染,部分水源地存在氟化物超标区和海水入侵区。结合调查数据和水源地的情况,查明了水源地污染的原因主要是农业、工业及农村非点源污染所致。     

物元分析方法在地下水质量综合评判中的应用

鉴于目前地下水质量评判方法中存在人为影响因素过多、权值计算的不确定性等不足，提出了一种基于物元分析理论的新评判方法，采用地下水质量综合评判的各种指标，根据计算出的综合关联度，实现对地下水质量等级的综合评判。实例表明该方法是可靠的，在地下水质量评判领域具有进一步的研究与应用价值。     

地下水取水总量控制管理技术研究

在对现有的地下水取水总量控制管理相关理念、制度、法律法规和技术方案等进行调查研究的基础上,以实现人类可持续发展为最终目标,秉承＂以人为本＂和＂统一管理＂的理念,制定出了一套以＂将地下水水位控制在合理水平＂为直接目的的地下水取水总量控制管理技术方案,以期为超采区内的地下水资源管理提供理论依据和技术参考。     

Impact of agriculture activities on a coastal aquifer in Tunisia and options for a better water management

The quality of a coastal aquifer (Korba, Tunisia) in a semi-arid agricultural region was studied by the collection and analysis of groundwater samples for their main chemical and biological parameters in relation to the SEQ evaluation system for groundwater quality. Results indicate important anthropogenic deterioration. Most of the samples were unsuitable for drinking-water production; animal drinking and irrigation with these waters will require caution. The high contamination is mainly due to the local intensive agriculture. Based on the objectives-oriented project planning method, regulatory and socio-economic instruments were extensively developed to encourage sustainable agriculture through a participatory exercise.     

Impacts of urban areas and urban growth on groundwater in the Great Lakes Basin of North America

The Great Lakes Basin (GLB) holds vast reserves of groundwater, the great majority of which eventually drains to the lakes. Urban growth significantly affects both the quality and quantity of this groundwater and thereby represents a potential threat to the long-term viability of the Great Lakes hydrologic system. Urban areas import, manufacture, store, transport, and utilise large volumes of chemicals, a proportion of which inevitably finds its way to the shallow sub-surface. In many cases, potentially polluting chemicals are applied directly to urban surfaces (e.g. as road salts, fertilizers and pesticides), are stored in the subsurface (e.g. gasoline tanks) or are released to the subsurface (e.g. septic systems). Because most of the basin's larger urban areas rely almost exclusively on lake-based supplies, very little attention is given to the accumulation of contaminants in shallow urban groundwaters and the serious risks they pose. Assessment of the problem is complicated by the widespread use of urban fill and a complex network of drains, pipes and tunnels that create “urban karst”, a shallow artificial aquifer, unique to urban settings, that exerts a major, yet often unpredictable influence on groundwater flow and contaminant transport. Management of ground water pollution, and its impact on the receiving Great Lakes, will require rigorous audits of all urban sources of contamination together with the development and calibration of groundwater flow and transport models that will enable the fate of urban pollutants to be reliably predicted even when groundwater is not used for supply.     

地下水资源管理工作评价方法及应用研究

在充分认识地下水资源管理工作的基础上,针对管理工作中的重点和定量评价中的难点,提出了一套地下水资源管理工作评价方法,包括评价指标体系、评价标准和计算方法,并将该评价体系应用于江苏省地下水资源管理工作的评价计算.结果表明,该评价方法科学、可行,可为指导地下水资源管理工作开展、强化监督管理提供技术支撑.     

地源热泵系统地下水热量运移模拟参数敏感性分析

基于敏感性分析理论,以某地下水源热泵系统夏季运行为例,选取典型观测点温度值及回灌水热量影响范围作为模型输出结果,从局部和全局定性、定量地讨论了热泵系统特定水流和热源条件下地下水热量运移模拟中参数的敏感性问题。结果表明:模型输出结果对所选参数的局部敏感性程度和趋势差别明显;全局敏感性分析中其他参数不同取值对待分析参数敏感性各参数间共同作用对模型均存在影响,各参数组合全局敏感性趋势变化基本一致,模型稳定性较好。     

A Stochastic Optimization Approach in the Design of an Aquifer Remediation under Hydrogeologic Uncertainty

A stochastic optimization approach is presented for the remediation design of a contaminated aquifer with limited hydrogeologic information. Stochastic simulation using the Monte Carlo technique, produces a series of equally probable realisations of the spatially varying random hydraulic conductivity field. The stochastic flow and transport simulation model is coupled, using the response matrix approach, with a nonlinear optimization algorithm. The whole process is integrated into an algorithm which is effectively applied in the case study of the Kalamaria aquifer, Chalkidiki, Greece. The stochastic optimization procedure is followed by a reliability analysis, giving useful information to the decision makers concerning the effectiveness of the optimal results.     

Groundwater Utilization and Management in the State of Kuwait

Abstract

The main brackish groundwater resources in the State of Kuwait are the groundwater located in the Kuwait Group and the Dammam limestone aquifers. Most of the groundwater used in the State of Kuwait is for irrigation, some part of it is used for domestic purposes and for small scale industries. Since rainfall is seasonal and is less than the annual evaporation, the recharge from rainfall is negligible. Water levels in both the aquifers are highly affected by the pumping rate from each well. The groundwater is extracted heavily resulting in decline of water levels and the deterioration of groundwater quality though there is underflow from Saudi Arabia. Improvement of the groundwater management is essential for maintaining long-term productivity of the aquifers in the State of Kuwait.     

Multi-parametric sensitivity analysis of CCHE2D for channel flow simulations in Nile River

Multi-Parametric Sensitivity Analysis (MPSA) is proposed to determine the relative importance of the different empirical parameters controlling flow field. CCHE2D which is one of the famous public unsteady-flow simulation software is applied to simulate the flow field at Elbogdady reach, at the south of Luxor staff gauge, 712.80 km upstream of Roda’s staff gauge on the Nile River. The main purpose of the paper is to apply the model in the considered river reach and to assess the capabilities of CCHE2D. Moreover, the paper presents findings of the authors in determining the model’s sensitivity analysis. Multi-Parametric Sensitivity Analysis results show that flow field in Nile River is controlled mainly by the bed roughness coefficient. In addition, the empirical formula of Van Rijn (1984) is found to be more efficient to calculate bed roughness.     

混凝土坝施工过程管理与控制研究

在施工项目控制理论基础上,提出了以反馈控制与前馈控制相结合的混凝土坝施工过程管理与控制模型,根据混凝土坝施工特性和施工过程管理与控制的客观需要,提出了施工进度影响因素辨识,施工条件敏感性分析,施工效果评估与趋势预测,施工进度纠偏调节等混凝土坝施工管理与控制方法,这些方法对混凝土坝施工管理与控制有很大的辅助作用。     

Risk-Based Decision Analysis in the Design of Water Supply Projects

The application of a decision analysis methodology to a small-scale water-supply/aquifer-contamination problem is presented. The main characteristic of the study is the development of a series of alternative strategies to ensure a continuous water supply to a village under variable risk conditions. It is assumed that the risks involved in the analysis reflect the uncertainty as to the hydraulic conductivity. Thus, a stochastic simulation model for groundwater flow and contaminant transport is employed in order to evaluate the implications of uncertainty in the system's behaviour upon the overall design decisions. Alternative decision strategies are formulated by considering both actual and probabilistic costs, and they are finally compared using a risk–cost–benefit objective function.     

石匣小流域综合治理试验示范研究项目综述

“北京市北部山区石闸小流域综合治理试验示范研究”项目是北京市科委“八五”期间立项研究的科研攻关项目。该项目将流域作为一个生态系统来研究,在资源综合调查评价的基础上,以改善生态环境、保护饮用水资源和提高当地群众生活水平为目的。以小流域为单元,开展流域水土保持生态环境建设治理模式、治理应用技术、水土流失及的流失的监测预报、流域治理管理、效益分析等研究。该项目完成后,已成为集水土保持综合治理、试验研究、户外教室展开、对外交流合作、环境保护为一体的水土保持综合示范区。     

延吉市地下水资源开发利用分析评价

分析了延吉市地下水资源开发利用中产生的环境地质问题,并对其进行了评价认为,延吉市地下水资源并不丰富,但可作为城市供水的重要补充水源。同时提出了城市地下水开采的保护规划和控制性措施。