Analysis of precipitation changes in the upper basin of the Yellow River
The upper basin of the Yellow River is an important water source conservation area in the Yellow River Basin,with natural runoff accounting for 62％of the annual average(1956-2000)total runoff.Precipitation chan-ges are not only the main influencing factor on water sources,but also related to changes in conservation capacity.Based on wavelet analysis,this paper uses a series of daily precipitation data from 43 meteorological stations in the upper basin of the Yellow River from 1960 to 2021 to analyze the precipitation changes in the upper basin,u-sing Mann Kendall test,anomaly method,frequency curve method,etc.The results show that:(1)the precipi-tation in the upper basin of the Yellow River can be divided into three distinct periods:1963 to 1981,1981 to 1999,and 1999 to 2018;(2)The annual precipitation from 1960 to 2021 shows an increasing trend of 4.9 mm/10 a,and the trend rates of annual precipitation during the three periods are-0.9 mm/10 a,-1.0 mm/10 a,and 46 mm/10 a,respectively;(3)From 1960 to 2021,74％of normal years have an annual precipitation a-nomaly percentage of-15％to 15％,while light drought years with an anomaly percentage of-30％to-15％and light flood years with an anomaly percentage of 15％to 30％account for 15％and 8％,respectively;3％of flood prone years have a percentage of anomaly between 30％and 40％.Drought and flood years generally occur in two periods:1963-1981 and 1999-2018;(4)The main difference in daily precipitation during the three periods is the frequency of precipitation less than 10％,which varies with altitude.The precipitation at Maqin Station from 1999 to 2018 increases at a rate of 25-45.4 mm/d compared to the past.The precipitation at Linxia Station from 1999 to 2018 increases at a rate of 20-50 mm/d.From 1963 to 1981,the precipitation at Wushenzhao Station in-creases at a rate of 50-65 mm/d compared to the past.
the upper reaches of the Yellow Riverprecipitationperiodicitytrendcharacteristicfrequency
万方数据
维普
