基于GPM数据的肃南地区降雨侵蚀力计算

Calculation of Rainfall Erosivity in Sunan Area Based on GPM Data

利用GPM逐日降雨资料结合随机森林非线性回归原理拟合降雨格点值与经度、纬度、DEM、坡度、坡向的关系从而建立肃南地区100m分辨率的降雨量降尺度模型,进而采用章文波公式得到区域精细尺度降雨侵蚀力。结果表明,肃南地区降雨侵蚀力介于48.24MJ·mm/(hm2·h·a)~187.56MJ•mm/(hm2·h•a),呈现自南向北减少格局。站点数据独立验证显示,该降尺度模型的R2达到0.83和0.95,降雨量和降雨侵蚀力的RMSE分别为51.02mm、35.17MJ·mm/(hm2·h·a),证明该方法具有较高准确性。

Use GPM daily rainfall data combined with random forest nonlinear regression principle to fit the relationship between rainfall grid value and longitude,latitude,DEM,slope,and aspect to establish a 100 m resolution rainfall downscaling model in Sunan area,and then adopt Zhang Wenbo formula Obtain the regional fine-scale rainfall erosivity.The results show that the rainfall erosivity in Sunan area ranges from 48.24 MJ•m m/(h m 2,h•a)to 187.56 MJ•m m/(h m 2•h•a),showing a pattern of decreasing from south to north.Independent verification of site data shows that the R 2 of the downscaling model reaches 0.83 and 0.95,and the RMSE of rainfall and rainfall erosivity are 51.02 m m and 35.17 M J•m m/(h m 2·h·a)respectively,which proves that the method is highly accuracy.