1961-2016年渭河流域极端降水事件研究

基于1961-2016年渭河流域26个气象站点的逐日降水数据,选取与极端降水事件密切相关的9个指数,利用线性趋势法、Mann-Kendall突变点检验和方差分析等方法,揭示渭河流域极端降水事件的变化趋势、突变情况以及渭河流域上、中、下游降水情况的差异特征,对研究区未来极端降水事件提供科学预测和理论参考。结果表明:①渭河流域上、中、下游地区及整个流域的年总降水量分别以16.588 mm/10a、8.319 mm/10a、6.703 mm/10a和9.544 mm/10a的速率下降,表明渭河流域56 a来降水总量存在逐年减少的趋势,整个渭河流域地区呈现变干的趋势。②降水强度(SDII)、强降水总量(R95PTOT)和极端降水总量(R99PTOT)在整体上均呈现上升趋势,极端降水总量的上升趋势高于强降水总量,上游地区的上升趋势高于中下游地区,表明渭河流域极端降水强度有所增强,极端降水事件发生频率有所增大。③渭河流域出现极端降水事件的年份集中在20世纪90年代和21世纪初期,且降水情况的年际差异较大,中游地区的变化更为明显。④相关分析显示中下游地区对整个流域极端降水事件的发生情况起到较大的贡献...

Extreme Precipitation Events in the Weihe River Basin from 1961 to 2016

Based on 26 of the Weihe River Basin from 1961 to 2016 in the daily precipitation data of weather stations, the selection is closely related to the extreme precipitation events 9 index, using the method of linear trend, Mann Kendall mutation point test and variance analysis, reveals the tendency of the extreme precipitation events, mutation of the Weihe River Basin and on, the precipitation of the middle and lower reaches of Weihe River Basin the differences of characteristics of extreme precipitation events for the study area in the future to provide scientific prediction and theory reference. The results showed that: 1) The annual total precipitation in the upper, middle and lower reaches of the Weihe River Basin and the whole basin decreased at the rates of 16.588 mm/10a, 8.319 mm/10a, 6.703 mm/10a and 9.544 mm/10a, respectively, indicating that the total precipitation in the Weihe River Basin has been decreasing year by year in the past 56 years, and the whole Weihe river Basin has been drying up. 2) Precipitation intensity (SDII), heavy rain amount (R95PTOT) and extreme precipitation amount (R99PTOT) tend to rise on the whole, extreme precipitation amount rise higher than the strong precipitation, rise higher than the middle and lower reaches area of the upstream region, shows that the strength of the Weihe River Basin in extreme precipitation increased, the extreme precipitation event frequency is increased. 3) The years of extreme precipitation events in the Weihe River Basin were concentrated in the 1990s and the early 21st century, and the inter-annual differences in precipitation were large, with more obvious changes in the middle reaches. 4) According to the results of relevant analysis, it is concluded that the middle and lower reaches of the basin to the occurrence of extreme precipitation events play a greater role.