تعيين مناطق همگن براي تحليل فراواني جريان كمينه

Identification of Homogenous Regions for Low Flow Frequency Analysis

In this study, two methods of multivariate techniques and CV-Based test were employed for the identification of homogenous regions for low flow frequency analysis. First a group of 17 variables including climatologic, physiographic, geologic and hydrologic factors of 16 recording stations in Atrak river basin were analyzed using component analysis to find homogenous regions. The analysis indicated the high importance of 4 factors namely basin area, annual precipitation, percentage of pervious formation, and slope of the basin. Spatial variations of data were then interpreted with distance-grouping technique resulting in two homogenous regions. In addition, annual low flows of 7, 15, 30 and 60-day duration in each station were calculated and CV-Base test estimated based on the coefficient of variations. Results showed the non-homogeneity of the whole area, however two homogenous areas were determined using cluster analysis.