Document Type : Research Paper

Authors

• Ali Reza Eslami ¹
• Abdol Rasoul Telvari ²

¹ MSc, Soil Conservation and Watershed Management Research Institute, Iran

² Associate Professor, Soil Conservation and Watershed Management Research Institute, Iran

Abstract

The hydrologic events and physical structure of a basin is related to governing climatic conditions. Basins have different hydrologic responses considering their various morphologic and climatic characteristics. It is recommended to separate basins with respect to their major factors into homogenous groups with the same hydrologic conditions. This grouping is effective so that models for estimating flood peak discharge in each homogenous group have higher performance than a single model for all basins. In this research, firstly different morphological characteristic of selected basins were derived using GIS. Based on factor analysis, major variables (factors) including; basin area, weighted-average slope, drainage density and annual mean precipitation were selected. Then, all basins were classified in homogenous groups with respect to major factors using cluster analysis and discriminate functions analysis, statistical methods, and Andrew’s curve as a graphical method. To investigate on the efficiency of grouping, two control basins were selected and their similarity to each homogenous group was carried out using above methods. By applying regression models developed for whole region and homogenous groups, flood peak discharges for two basins with different return periods were estimated. Simulated values compared with observed data and showed that models for homogenous groups have better performance than those for the whole region.

Keywords

• Homogenous groups
• Factorial analysis
• cluster analysis
• Discriminate Functions Analysis
• ‎Andrew’s curve
• Khazar basin