Journal of Water Resources Planning and Management

A decision support system for reservoir water management conflict resolution (RWM-CRSS) in a multipurpose single reservoir system has been developed. The system consists of a communication system, a database management system, and a model-base management system. A new approach is used in developing the communication system, in which the use of artificial intelligence markup language facilitates the task of developing human-like communication between the stakeholders and the system. Tools that are common to analyze a multipurpose single reservoir system are provided in the model-base management system. RWM-CRSS is designed to handle conflict between two groups who have on-demand water requirements for irrigation, drinking water, hydropower generation, or minimizing flood damage. A hypothetical scenario of irrigation versus drinking water supply is demonstrated.

Western Inner Mongolia is located in the downstream area of the Hei River Basin, the second largest inland basin in China. Since the 1960s, water depletion in the basin has increased very rapidly due to intensive irrigation development in the middle stream area of the Basin. As a result, the downstream Erjina Oasis gradually receded and the destination inland lake disappeared. In the late 1990s, the Chinese government initialized activities for the ecological restoration of the region, including annual flow releases to downstream by administrative order. These releases have contained further degradation of the ecosystem. The challenge that needs to be addressed now is how the short-term administered flow releases can be converted into sustainable water management practices. In particular, research on the determination of environmental flow requirement and livestock carrying capacity will be important for decision making support in the sustainable development of the region.

This paper develops a multicommodity flow model to optimize water distribution and water quality in a regional water supply system. Waters from different sources with different qualities are considered as distinct commodities that concurrently share a single water distribution system. The model can accommodate two-way flow pipes, represented by undirected arcs, and the perfect mixing condition. Additionally, blending requirements are specified at certain control nodes within the system to ensure that downstream users receive the desired water quality. The optimization model is highly nonlinear and solved by a hybrid genetic algorithm (GA). The GA is first used to globally search for the directions of all undirected arcs. Then a generalized reduced gradient (GRG) algorithm embedded in the GA is used to optimize the objective function for fitness evaluation. The proposed methodology was first tested and verified on a hypothetical system and then applied to the regional water distribution system of the Metropolitan Water District of Southern California. The results obtained indicate that the proposed hybrid GA is a viable way of converting an undirected network to a directed network by separating the complicating variables, and that the resulting directed network model can be solved iteratively and efficiently by a gradient-based algorithm.

A distributed hydrologic model of an urban watershed in the northeast United States was developed and combined with a genetic algorithm to determine the optimal location of infiltration-based best management practices (BMPs) for storm water management. The distributed, event-based hydrologic model integrates the curve number method with a distributed hydrologic network model of the catchment using a system of 4,533 hydrologic response units (HRUs). The infiltration-based BMP was conceptualized as an element that alters the infiltration/runoff partitioning of the HRUs in which it was applied. The results indicate that the optimal location and number of BMPs is a complex function of watershed network connectivity, flow travel time, land use, distance to channel, and contributing area, requiring an optimization approach of the type introduced here. A Pareto frontier describing the trade-off between the number of BMPs, representing project cost, and watershed flooding was developed.

The proactive approach to drought management is based on measures devised and implemented before, during, and after the drought event, according to a planning strategy rather than within an emergency framework. The measures taken before the initiation of a drought event consist of long-term measures oriented to improve the reliability of the water supply system to meet future demands under drought conditions. The measures taken after a drought is forecasted or starts are short-term measures that try to mitigate the impacts of the particular drought on the basis of a contingency plan. Selection of the preferable mix of long-term and short-term measures can be accomplished through multicriteria decision analysis (MCDA), which enables the comparison of alternatives on the basis of appropriate quantitative and/or qualitative assessment criteria. In this paper, a methodology for the assessment of drought mitigation measures based on a combined use of simulation models and MCDA is applied to a water supply system located in eastern Sicily, Italy. The system comprises two reservoirs and several diversion dams and hydropower plants, and its main uses are irrigation and municipal water supply. First, a simulation model is applied to evaluate the effects of several drought mitigation alternatives consisting of a mix of long- and short-term measures. Then, MCDA is applied to rank the different alternatives on the basis of economic, environmental, and social criteria, taking into account the process of coalition formation among stakeholders on the basis of their different point of view. The results confirm the applicability of the proposed multicriteria methodology for a transparent comparison of drought mitigation measures to be adopted as a support for the decision making process.

Presented herein is a methodology for evaluation of water losses based on discrimination of the two components of uncontrolled water in a water distribution network: physical losses in mains and service connections, and the volume of water consumed but not measured by meters. The water balance calculations consider that all nonmeasured consumption is uncontrolled water and consequently an apparent loss. The methodology is applicable to an entire network or portions thereof, and presumes that real losses in certain physical states of a network are a function of pressure, while apparent losses (defined as nonmetered consumed water) are a function of consumption patterns (i.e., domestic, industrial, institutional, etc.). An extended period simulation of a water distribution network is employed to accurately determine both terms.

An original approach to the optimal design of water distribution networks is presented in this paper. Multiobjective optimization is applied, i.e., minimizing costs and maximizing a benefit/quality function, the tradeoff curve being produced by a genetic algorithm. Fuzzy reasoning is introduced to the evaluation of benefits for each potential solution. A number of criteria are introduced, individually assessed by fuzzy membership functions and combined as a whole using fuzzy aggregation operators. Additionally the paper includes a novel approach for the simulation of tanks as network storage components within the genetic algorithm, taking into account the tank shape. The model is applied to a well-known example from the literature, the “Anytown” water distribution network, to benchmark the results. Comparison of results shows that the model manages to find a better solution than any other previous approach in terms of cost, despite the multiple criteria applied for the benefit function being more extensive and stricter.