Analysis of the Characteristics of Runoff in Manasi River Basin in the Past 50 Years.

Abstract: Runoff generated in the upper Manasi River Basin is water resource supplied for the middle and lower reaches. Based on the monthly runoff series (1957-2006) of the two hydrological gauging stations, Kensiwate, Hongshanzui and precipitation series at 4 precipitation stations of the upper Manasi River Basin, multiple indexes and a series of methods and wavelet methods are adopted to analyze the inter-annual, annual and periodic variation characteristics of the streamflows in the watershed for the last 50 years. The results show that: showed that: (1) Distribution of annual runoff was uneven, and mainly focuses on June and july and August. The inter-annual variations were great, with significant difference between the wet year and dry year; (2) annual runoff changes had obvious stages and the tendency of annual runoff increasing was significant; and (3) annual runoff changes had a main period of about30 years and 15 years, with an abrupt point happening in 1995. The increasing of precipitation and Climate warming are the key factors influencing the runoff. [Copyright &y& Elsevier]