基于GIS的四川省区域性暴雨降水分布的空间插值方法与面积估测

暴雨是四川省主要的灾害性天气之一,每年由暴雨引发的次生灾害在全省造成严重的人员伤亡和经济损失。本研究利用四川省5006个气象站逐日降水量资料,采用距离权重反比法(IDW)和普通克里金插值法(Ordinary Kriging)法对2018年8次区域性暴雨过程降水分布进行计算,统计出不同降水等级的面积及面积比例,并对两种插值方法的的计算精度进行了评估。结果表明:(1)在8次区域性降水过程中的距离权重反比法(IDW)和普通克里金插值法(Ordinary Kriging)法的平均相对误差均低于7%,有较高的计算精度;(2)2018年区域性暴雨降水主要分布于盆地西北部、盆地南部和盆地东南部地区,川西高原与攀西地区降水量相对较小;(3)8次区域性暴雨过程中,过程累计降水量>50mm的面积在20247~158144km2,面积比率在4.17%~32.54%。分析发现,暴雨面积能更较好的反映出一场暴雨天气过程的影响范围,同时也可以作为区域暴雨的判别指标。 

Study of Spatial Interpolation Method and Area Estimation for Regional Rainstorm Precipitation Distribution in Sichuan

Heavy rainstorm is one of the main disastrous weather in Sichuan province,which can trigger secondary disasters and cause serious personnel casualty and economic loss.Based on the daily precipitation data of 5006 meteorological stations in Sichuan Province,this study adopts IDW method and ordinary kriging method to calculate the precipitation distribution for eight regional rainstorm processes,and calculate the area and area ratio of different precipitation grades.Meanwhile,the accuracy of calculation results are also assessed.The results show that:1) For eight regional rainstorm processes,the mean relative error of IDW and ordinary kriging method lower than 7%,so both methods have a satisfied accuracy for precipitation distribution calculation;2) In 2018,regional rainstorm mainly distributes in the northwest,south and southeast of the basin,while in the western Sichuan plateau and Panxi district the precipitation is relatively small.3) For eight regional rainstorm processes cumulative precipitation more than 50 mm,the area range from 20247km 2 to 158144 km2 and the area ratio range from 4.17%-32.54%.Through analysis,we find that the rainstorm area can better reflect the impact range of a rainstorm process,and can also be used as a discriminant index of regional rainstorm.