Vulnerability Analysis of Flood in Rangelands Using Multi Criteria Decision Analysis and Geographic Information System (Case Study: Gilard Basin, Damavand, Iran(

Abstract

Flood disaster is considered as a major natural hazard due to its devastating<br />effects on the affected areas. Determining the flood vulnerable areas is important for<br />decision makers in order to perform planning and management activities. Geographical<br />Information System (GIS) is integrated with Multi Criteria Decision Analysis (MCDA)<br />used to analyze the flood vulnerable areas. The aim of this research was to provide more<br />flexible and accurate decisions to evaluate the causative factors for planning and<br />management of rangelands of Gilard, Damavand. So, effective factors influencing flood<br />occurrence in the study area was first surveyed. Some of the causative factors for flood in<br />the watershed such as mean annual precipitation, basin area, basin slope, drainage density,<br />land uses and soil type were taken into account. Then, through assembling spatial and<br />descriptive information related to the study area and using Analytic Hierarchy Process<br />(AHP), the criteria have been grouped and weighted. At the end, as regards of ultimate<br />weight, the basin was classified into five classes. Results of this research show that mean<br />annual precipitation and Sedimentation Rate with the average values of 26.5% and 2.01%<br />had maximum and minimum effects on flood occurrence in rangeland of Gilard in<br />Damavand, respectively.