1960-2020年黄河流域不同等级降水时空特征OA北大核心CSTPCD

The Yellow River Basin is an important ecologically fragile area in China.The clarification of the rela-tionship between different levels of precipitation,precipitation days,and precipitation intensity in the basin is im-portant to characterize the precipitation patterns in the basin.Using precipitation data collected from 96 meteoro-logical stations in the Yellow River Basin from 1960 to 2020,the spatial and temporal variation characteristics of different grades of precipitation in the basin were analyzed using mathematical statistics and Pearson correlation analysis,and the contribution and impact of different grades of precipitation on the total precipitation were dis-cussed.In the studied recent 61-year period,the annual precipitation and precipitation intensity in the Yellow Riv-er Basin followed increasing trends with rates of 0.008 mm·(10a)-1 and 0.12 mm·d-1·(10a)-1,respectively.The number of precipitation days followed a decreasing trend with a rate of-1.82 d·(10a)-1.The rainfall and days of light rain and moderate rain followed a downward trend;the amount and number of days of heavy rain,rain-storm,and heavy rainstorm followed an upward trend,and the precipitation intensity of each grade followed an increasing trend.Over the recent 61-year studied period,the highest occurrence rate of light rain was 84.32%,with the highest contribution rate from light rain(37.64%)followed by moderate rain(34.47%).The occurrence rate and contribution rate of light rain followed decreasing trends,whereas the occurrence rate and contribution rate of precipitation of heavy rain followed increasing trends.The areas with high values of light precipitation,light precipitation days,and light precipitation intensity were mainly concentrated in the southwest of the basin.As the precipitation level increased,the areas with high precipitation,precipitation days,and precipitation intensi-ty were mainly concentrated in the southeast of the basin.Correlation analysis revealed that the annual precipita-tion of the Yellow River Basin was strongly affected by moderate and heavy rainfall,the annual precipitation days were strongly affected by the light rain days,and the annual precipitation intensity was strongly affected by the amount of heavy rain,rainstorm,and precipitation days.These findings can support ecological protection in the basin.