نوع مقاله : پژوهشی
نویسندگان
1 استادیار دانشکدۀ کشاورزی و منابع طبیعی، دانشگاه تربت حیدریه
2 کارشناسی ارشد آبخیزداری، دانشکدۀ کشاورزی و منابع طبیعی، دانشگاه تربت حیدریه
3 استادیار پژوهشکدۀ حفاظت خاک و آبخیزداری کشور، تهران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Regional analysis is one of the important methods for estimating the low flow in ungagged regions. Investigation of the relations between effective factors of hydrological drought is the most important strategy to contrast and reduction of drought losses. In this study to analyze of low flow, the daily discharge data from 20 gauging stations with 25 years period (1988-2012) in the Kashafroud basin have been used. Low flow series with durations of 7 and 15 days have been calculated and by using frequency analysis, Log Pearson type III distribution was recognized as the most appropriate distribution. Then, low flows with return periods of 2, 5, 10, 25, 50 and 100 years were calculated. After calculating the physical characteristics of basins effective parameters on low flow have been detected in two steps by factor analysis. Based on cluster analysis, studied basins divided to two homogenous regions and the low flow regional models were determined in each homogenous region by using the linear multivariate regression. Results showed the first and second factors indicated 66.1% and 24.2 % of variance. Basin area, mean of slope and drainage density are the most effective physiographical parameters to estimation of low flow discharge and respectively in 100%, 79% and 79% of significant regression models are known as effective parameters in estimation of low flow in both A and B homogenous regions. In addition,with regards to high coefficient of determination and low standard error of relationships, models for homogeneous regions compared with the whole area models are more accurate.
کلیدواژهها [English]