Turkey Assessment of the watershed yield of the Sakarya river basin

The purpose of this study is to classify watershed yields into homogeneous regions and identify the regional membership of watersheds. Monthly river yields of 118 gauging stations in the Sakarya River basin, which is located in northwestern Turkey, were classified by cluster analysis on the basis of hydrological homogeneity. An agglomerative hierarchical clustering algorithm is used so that stations from different geographical locations are considered in the same cluster independently of their geographical location. The study uses Ward's minimum variance linkage method together with the Euclidean distance similarity measures in order to determine the number of homogeneous regions. The Sakarya River basin is clustered into three homogeneous regions and the yield distribution map of the basin is obtained. Out of 118 stations used in this study, 74 gauging stations were grouped into cluster 1, 32 into cluster 2, and 12 into cluster 3. The average watershed yields for each cluster are 0.001966, 0.007336 and 0.01826, respectively, and the average watershed yield of all the basins is 0.005066. Correlation between modelled specific yield and observed yield from gauging stations within each cluster varied from 0.77 to 0.99. Copyright 2007 IAHS Press.

Assessment of the watershed yield of the Sakarya river basin, Turkey Conference Paper