Variation and Trend Analysis of Rainfall in Qingshui River Basin of Ningxia in China

Abstract

The study on the variation law and trend of rainfall characteristics of Qingshui River, a typical tributary of the upper Yellow River in China, is of great significance to reveal the cause of runoff and sediment change in the Yellow River. According to the daily rainfall data on 93 rainfall stations in the Qingshui River Basin from 1958 to 2015, the rainfall characteristics of the basin, such as annual rainfall, flood season rainfall, and main flood season rainfall were calculated. Using time-domain analogy, Mann-Kendall trend and abrupt change point test, coefficient of variation, etc., the variation and trend of rainfall characteristic values in the past 60 years were analyzed. The results showed that the distribution of rainfall during the periods from 1970 to 1979 and 2010 to 2015 was significantly different from other periods. There is no significant trend change in rainfall characteristic values from 1958 to 2015. From 1958 to 2015, the intensity of discrete changes in the rainfall characteristics of different series from small to large is the annual rainfall, flood season rainfall, and main flood season rainfall. The intensity of the discrete changes in main flood season rainfall gradually decreased with time.