An optimization model for treatment and allocation of water resources -

Abstract

Increasing population, diminishing supplies, and climate changes may cause difficulty in meeting water demands. Scarcity in water resources is a major concern for water resources planners all over the world. Water requirements are exceeding the availability of fresh water resources, so desalination and water reuse are becoming increasingly popular in sustainable water management. The objective of this thesis is to introduce an optimization-based decision support system for the treatment and allocation of water resources. The developed approach targets the minimization of the overall economic cost of the water treatment and distribution system, as well as the associated environmental cost of the employed treatment processes, transportation, construction and maintenance, etc… The system considers the available sources of water, the locations of treatment plants and applicable technologies, and the demand for water and provides an optimal solution on the volume of water from each source to be transported to each plant and treated by an appropriate technology in order to satisfy certain demand at the lowest possible overall economic and environmental cost. We propose an integer program as a mathematical formulation of the problem addressed. To achieve this formulation, we gather data on economic and environmental costs of different water treatment options from a variety of sources, and model the cost functions based on the gathered data. We also propose an alternate decision support system based on multi-criteria decision analysis to incorporate the qualitative criteria (such as social criteria) that may affect the decision maker’s choice in addition to quantitative criteria. This allows the comparison among all possible treatment alternatives, and considers the key criteria involved in the selection of alternatives, giving each criterion a weight based on its importance in the decision. The use of the proposed decision tools, instead of intuitive judgments, could assist in improving the quality of th