Sub-Watersheds Classification Based on Morphometric Parameters Using Cluster Analysis in Pol-Doab Shazand Watershed

Morphometric analysis provides a quantitative description of geometric characteristics in a watershed to understand its morphologic conditions. These characteristics play an important role to estimate hydrologic variables in ungauged watersheds. In such watersheds, determination of morphometric similarities among sub-watersheds helps to prioritize soil and water conservation measures. In this study multi-averaging clustering technique or K-means Cluster Analysis (KCA) and Hierarchical Cluster Analysis (HCA) have been used to classify 24 sub-watersheds in Pol-Doab Shazand watershed using 10 morphometric parameters. After extracting morphometric parameters data were standardized. To determine proper numbers of clusters, Davis-Bouldin Index was used. Considering this index, 5 clusters have been chosen to do final classification of the sub-watersheds. The Results show that number of sub-watersheds based on KCA technique is 3, 7, 3, 7 and 4 for clusters 1, 2, 3, 4 and 5, respectively. The results indicate that number of sub-watersheds based on HCA technique is 3, 7, 2, 8 and 4 for clusters 1, 2, 3, 4 and 5, respectively. Comparison of the results reveals that 23 sub-watersheds (95%) out of 24 can be classified based on both techniques of KCA and HCA.