Spatiotemporal Variability Characteristics of Precipitation Pattern in Weihe River Basin
CAI Xinling;CAI Yixuan;YE Dianxiu;QIAO Qiuwen;LU Cenzhi;ZHAO Xiaomeng;LI Qian;Shaanxi Provincial Climate Center;Zhouzhi county Water Authority;National Climate Center;Northwest Electric Power Dispatching and Control Sub-center of State Grig;
In order to study the temporal and spatial variation of precipitation pattern in Weihe River Basin under the background of climate change,the change trend of precipitation pattern and the spatial variation characteristics of different precipitation durations and different precipitation grades were discussed by using the incidence rate,contribution rate of precipitation and the method of linear tendency rate and non-parametric Mann-Kendall test.The data included hourly precipitation covering 1981—2012 in 71 meteorological stations in the Weihe River basin.The results show that:(1)the precipitation occurrence rate decreases rapidly with the increase of precipitation time;the contribution rate of precipitation increases rapidly with the increase of precipitation time,and then decreases in Weihe River Basin;the short duration precipitation has a high occurrence rate and the contribution rate in the upper reaches of the river basin,and the duration precipitation occurrence rate and contribution rate are higher in the middle and lower reaches of the river basin;(2)the long duration precipitation rate and contribution rate show the decreasing trend from 1 to 6 hof short duration and more than 48 hours in Weihe River Basin,and the increasing trend in 7 to 24 h,This trend is more significant in the middle and lower reaches of the basin;(3)the precipitation rate decreases exponentially with the increase of precipitation grades,the occurrence rate of sprinkle is the highest,and the rainstorm is the lowest in Weihe River Basin;the occurrence rate and contribution rate of sprinkle and moderate rain are higher in upstream,and heavy rain and rainstorm are higher in the middle and lower basin,especially in the mainstream of Weihe River,the rainstorm contribution rate is more than 25%;(4)the occurrence rate andcontribution rate of sprinkle show a significant downward trend and the rainstorm performs an increasing trend in Weihe River Basin,this trend will likely make the watershed flood control situation tends severe.
【Fund】： 陕西省自然科学基础研究计划项目“基于相似理论的渭河致洪秋雨短期气候预测方法研究”(2012JM5012);“陕西省环境气象影响评估及霾预测研究”(2014JM2-4038);; 陕西省社发攻关项目“陕西气象干旱事件监测预警及评估技术研究”(2016SF-419)
【CateGory Index】： P426.6
【CateGory Index】： P426.6