APPLICATION OF GIS AND MULTICRITERIA DECISION MAKING IN SUPPORT OF EARTH-FILL DAM DESIGN

Abstract

Scarcity of water due to drought cycles on the globe makes the construction of dams across rivers or valleys very important. There is a large number of dams in worldwide, completed or under construction. Embankment dams are the predominant type followed by gravity and arch dams. Generally, site conditions may lead to selection dam type. Where the first step of dam design is the selection of the most suitable site for dam construction. The dam site selection is considered as a multi-faceted challenge. Dam site selection does not only involve numerous technical requirements, but also, may include economic, social, environmental, and political dimensions that may have conflicting values. Geographic information systems (GIS) and multi-criteria decision-making techniques (MCDM) are the most common tools employed to solve dam site selection problems. The main objective of this study is to develop a multi-criteria decision algorithm capable of selecting the optimum dam site and its main specifications when planning to design dams, taking into consideration all available data in short time and high flexibility. The algorithm is composed of three stages of analysis. The first stage is to generate a suitability map for dam site inside the entire study area, while the second stage is designed to select the most suitable location of the proposed dam among the highly suitable sites found in the first stage. The third stage is design of the cross section of suggested dam.