基于GIS的平洛河流域降水量时空变化特征及趋势研究OA

To better understand the spatiotemporal characteristics of precipitation in the Pingluo River Basin and provide data support for disaster prevention,mitigation,and hydrological forecasting,precipitation observations from eight representative stations were collected.Based on GIS,multiple hydrometeorological statistical methods-including the hydrological statistics method,cumulative departure curve,linear trend analysis,Spearman's rank correlation,non-parametric Z-test,cumulative sequence method,and Mann-Whitney-Pettitt test-were applied to analyze precipitation variability and long-term trends.Results show that the multi-year average precipitation in the basin is 676.4 mm,exhibiting relatively stable interannual variation.From 1977 to 1993,precipitation displayed an increasing trend;from 1994 to 2015,a decreasing trend;and from 2016 to 2021,a renewed increasing trend,with approximate cycles of 17,20,and 6 years,although no clear periodicity was observed.Spatially,precipitation decreases from upstream to downstream and from southwest to northeast.Overall,precipitation shows a non-significant increasing trend,with abrupt changes detected in 1993 and 2016.The results provide essential support for hydrological forecasting and flood-drought mitigation in the basin.