Daene C. McKinney

Genetic algorithm solution of groundwater management models

Groundwater simulation models have been incorporated into a genetic algorithm to solve three groundwater management problems: maximum pumping from an aquifer; minimum cost water supply development; and minimum cost aquifer remediation. The results show that genetic algorithms can effectively and efficiently be used to obtain globally (or, at least near globally) optimal solutions to these groundwater management problems. The formulation of the method is straightforward and provides solutions which are as good as or better than those obtained by linear and nonlinear programming. Constraints can be incorporated into the formulation and do not require derivatives with respect to decision variables as in nonlinear programming. More complicated problems, such as transient pumping and multiphase remediation, can be formulated and solved using this method. The computational time required for the solution of genetic algorithm groundwater management models increases with the complexity of the problem. The speedup attainable by solving genetic algorithm problems on massively parallel computers is significant for problems where the simulation time required to complete each generation is high. 47 refs., 9 figs., 5 tabs.

Integrated economic-hydrologic water modeling at the basin scale: the Maipo river basin

Increasing competition for water across sectors increases the importance of the river basin as the appropriate unit of analysis to address the challenges facing water resources management; and modeling at this scale can provide essential information for policymakers in their resource allocation decisions. This paper introduces an integrated economic-hydrologic modeling framework that accounts for the interactions between water allocation, farmer input choice, agricultural productivity, nonagricultural water demand, and resource degradation in order to estimate the social and economic gains from improvement in the allocation and efficiency of water use. The model is applied to the Maipo River Basin in Chile. Economic benefits to water use are evaluated for different demand management instruments, including markets in tradable water rights, based on production and benefit functions with respect to water for the agricultural and urban-industrial sectors.

Partitioning Tracer Test for Detection, Estimation, and Remediation Performance Assessment of Subsurface Nonaqueous Phase Liquids

In this paper we present a partitioning interwell tracer test (PITT) technique for the detection, estimation, and remediation performance assessment of the subsurface contaminated by nonaqueous phase liquids (NAPLs). We demonstrate the effectiveness of this technique by examples of experimental and simulation results. The experimental results are from partitioning tracer experiments in columns packed with Ottawa sand. Both the method of moments and inverse modeling techniques for estimating NAPL saturation in the sand packs are demonstrated. In the simulation examples we use UTCHEM, a comprehensive three-dimensional, chemical flood compositional simulator developed at the University of Texas, to simulate a hypothetical two-dimensional aquifer with properties similar to the Borden site contaminated by tetrachloroethylene (PCE), and we show how partitioning interwell tracer tests can be used to estimate the amount of PCE contaminant before remedial action and as the remediation process proceeds. Tracer tests results from different stages of remediation are compared to determine the quantity of PCE removed and the amount remaining. Both the experimental (small-scale) and simulation (large-scale) results demonstrate that PITT can be used as an innovative and effective technique to detect and estimate the amount of residual NAPL and for remediation performance assessment in subsurface formations.

Solving nonlinear water management models using a combined genetic algorithm and linear programming approach

Abstract Gradient-based nonlinear programming (NLP) methods can solve problems with smooth nonlinear objectives and constraints. However, in large and highly nonlinear models, these algorithms can fail to find feasible solutions, or converge to local solutions which are not global. Evolutionary search procedures in general, and genetic algorithms (GAs) specifically, are less susceptible to the presence of local solutions. However, they often exhibit slow convergence, especially when there are many variables, and have problems finding feasible solutions in constrained problems with “narrow” feasible regions. In this paper, we describe strategies for solving large nonlinear water resources models management, which combine GAs with linear programming. The key idea is to identify a set of complicating variables in the model which, when fixed, render the problem linear in the remaining variables. The complicating variables are then varied by a GA. This GA&LP approach is applied to two nonlinear models: a reservoir operation model with nonlinear hydropower generation equations and nonlinear reservoir topologic equations, and a long-term dynamic river basin planning model with a large number of nonlinear relationships. For smaller instances of the reservoir model, the CONOPT2 nonlinear solver is more accurate and faster, but for larger instances, the GA&LP approach finds solutions with significantly better objective values. The multiperiod river basin model is much too large to be solved in its entirety. The complicating variables are chosen here so that, when they are fixed, each periods model is linear, and these models can be solved sequentially. This approach allows sufficient model detail to be retained so that long-term sustainability issues can be explored.

Sustainability analysis for irrigation water management in the Aral Sea region

Sustainable irrigation water management should simultaneously achieve two objectives: sustaining irrigated agriculture for food security and preserving the associated natural environment. A stable relationship should be maintained between these two objectives now and in the future, while potential conflicts between these objectives should be mitigated through appropriate irrigation practices. The Aral Sea region in Central Asia is such a region that is most famous for its conflict between sustaining irrigated agriculture and preserving the environment. The current status of irrigation water management in the Aral Sea region demonstrates the Aral Sea disaster as a prime example for unsustainable irrigation development. This paper presents an integrated modeling framework for sustainable irrigation management analysis and applies it to analyze irrigation water management in the Aral Sea region. Based on the modeling outputs, alternative futures of the irrigation practice in the region are explored and it is found that to maintain current irrigation practices will lead to worsening environmental and economic consequences. Investments in infrastructure improvements (about annualized US

Sustainability Index for Water Resources Planning and Management

299 million) and crop pattern change will be necessary to sustain the irrigated agriculture and the associated environment in the region. Moreover, a penalty tax on salt discharge less than 50 US

Approximate Mixed‐Integer Nonlinear Programming Methods for Optimal Aquifer Remediation Design

per ton as an economic incentive may help address environmental problems, while having only a small effect on irrigation profit.

Bridges Over Water:Understanding Transboundary Water Conflict, Negotiation and Cooperation

This paper presents a water resources sustainability index that makes it possible to evaluate and compare different water management policies with respect to their sustainability. The sustainability index identifies policies that preserve or improve the desired water management characteristics of the basin in the future. This index is based on a previous sustainability index with improvements in its structure, scale, and content to make it more flexible and adjustable to the requirements of each water user, type of use, and basin. The Rio Grande transboundary basin is used as a case study demonstrating the use of the index. Tailor-made sustainability indexes are defined for water users in Mexico, the United States, the environment, and for meeting system requirements (international treaty obligations). Group sustainability indexes are calculated to summarize the results for groups of water users of each country, the environment, and the basin as a whole. Sustainability indexes by subbasins are calculated ...

Linking GIS and water resources management models: an object-oriented method

An optimal aquifer remediation design model employing a nonlinear programming algorithm was developed to find the minimum cost design of a pump-and-treat aquifer remediation system. The mixed-integer nonlinear programming model includes the discontinuous fixed costs of system construction and installation as well as operation and maintenance. The fixed cost terms in the objective function have been approximated by continuous functions of the decision variables using a polynomial penalty coefficient method resulting in a nonlinear programming formulation of an otherwise mixed-integer nonlinear programming model. Results of applying the new polynomial penalty coefficient method to an example design problem show that a combined well field and treatment process model hat includes fixed costs has a significant impact on the design and cost of aquifer remediation systems, reducing system costs by using fewer, larger flow rate wells. Previous pump-and-treat design formulations have resulted in systems with numerous, low flow rate wells due to the use of simplified cost functions that do not exhibit economies of scale or fixed costs. The polynomial penalty coefficient method results were compared to two alternative approximate mixed-integer nonlinear programming methods for solving optimal quifer remediation design problems, the pseudo-integer method and the exponential penalty coefficient method. The polynomial penalty coefficient method obtains the same solutions and performs as well as or better than the exponential penalty coefficient method. The polynomial penalty coefficient method almost always results in better, less expensive designs and requires significantly less computer time than the pseudo-integer method.

Network design for predicting groundwater contamination

Bridges over Water places the study of transboundary water conflicts, negotiation, and cooperation in the context of various disciplines, such as international relations, international law, international negotiations, and economics. It demonstrates their application, using various quantitative approaches, such as river basin modeling, quantitative negotiation theory, and game theory. Case-studies of particular transboundary river basins, lakes, and aquifers are also considered. This second edition updates the literature on international water and in-depth analyses on political developments and cooperation between riparian states. With an appended chapter on principles and practices of negotiation, and a new case study on the La Plata Basin, this edition is a timely update to the field of transboundary water studies. Contents: Introduction: State of Water and Interstate Water Relations Overview of Literature on Conflict Negotiation and Cooperation Over Shared Waters The Development and Application of International Water Law Principles and Practices of Cooperation in Managing International Water Cooperative Game Theory and Water Resources: Principles Cooperative Game Theory and Water Resources: Application of Solution Concepts Principles and Practices of Negotiation: A Quantitative Approach Hydropolitics and International Relations An Overview of Selected International Water Treaties in Their Geographic and Political Contexts Global Analysis of International Water Agreements The Use of River Basin Modeling as a Tool to Assess Conflict and Potential Cooperation Conclusion Case Studies: The Mekong River Basin The Ganges Basin (With Focus on India and Bangledesh) The Indus River Basin The Aral Sea Basin The La Plata River Basin Annexes: The Generica: An Outline for Preparing a Basin Case Study River Basin Cooperative Game Theory Example Readership: Graduates in economics, engineering, water law, international relations and practitioners in water resource management, international water law and water policies. Key Features: An original textbook that combines several disciplines that together allow understanding and analyzing of conflict, negotiation and cooperation in transboundary water A balanced set of conceptual approaches and case studies from all over the world Supplementary material include: a computer program that allows users to practice various concepts of cooperation, demonstrating them via quantitative examples and outcomes, various annexes of treaties Each chapter includes sections on chapter objectives; glossary of main terminology; summary; practice questions; and list of recommended readings