基于随机森林模型的云南元阳梯田地形因子分析  

Analysis on topographic factors of the Yuanyang terrace in Yunnan Province based on random forest model

作　　者：赖自力[1] 向杰[1] 陈建平[1,2] 王文杰[1] 田夏一 胡彬[1] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]北京市国土资源信息研究开发重点实验室,北京100083

出　　处：《地质学刊》2016年第3期518-525,共8页Journal of Geology

基　　金：中国地质调查局项目"矿山环境变化自动监测示范研究"(1212011120029)

摘　　要：为探究地形因子对梯田空间分布的影响,以云南元阳梯田坝达流域为研究区,运用GeoEye-1遥感卫星数据(2010年,1 m分辨率)和数字高程模型(20 m分辨率),提取梯田空间分布信息以及海拔高程、地形坡度、地形坡向、地面曲率、高程变异系数、地形起伏度、地面粗糙度、地表切割度、到水系距离9个地形因子。采用随机森林(Random Forest)方法建模,结合ROC曲线和AUC值对模型进行精度评价,根据随机置换残差均方减少量和因子作用曲线,探讨地形因子对梯田分布的影响规律。研究结果表明:该流域内梯田总面积1 158395 hm2,模型AUC值为0.947,海拔高度因子的随机置换残差均方减少量为38814,到水系距离因子为199.77,地面坡向因子为80.26,三者占总值的73.45%。由此可见,元阳梯田的空间分布主要受海拔高度、到水系距离、地面坡向3类地形因子的影响,其因子曲线表明梯田分布与地形因子间呈非线性关系。To explore the impact of topography on the spatial distribution of the Yuanyang terrace, this study used the GeoEye-1 （ year of 2010, 20 m resolution） remote sensing data to extract the spatial distribution of this terrace, and acquired the terrain features based on the digital elevation model（ 20 m resolution）. These terrain features include altitude, slope, aspect, surface curvature, variance coefficient of elevation, undulating terrain, surface roughness, surface cutting degree and the distance to the water system. This research used the factor curves to display the relationship between the terrain factors and terrace based on the random forest modelling. In addition, we employed the ROC curves and AUC to evaluate the accuracy of the model. The result shows that the terraced area is 1 158. 395 hm^2 acres in the study area and the value of AUC is 0.947. It shows that the random forest model is suitable for the terrace research. Furthermore, the value of random permutation residual mean square reduce is 388.14 in altitude and 199.77 in the distance to the water system and 80.26 in slope; these three terrain factors account for 73.45% of the total terrain factors. Thus, the spatial distribution of the Yuanyang terrace is mainly affected by the altitude, the distance to the water system, and the slope. Moreover, the terrain factor has a non-linear relationship with the terrace according to the factor curve based on random forest model.

关 键 词：地形因子 元阳梯田 随机森林 因子评价 云南 

分 类 号：P237[天文地球—摄影测量与遥感] F301.2[天文地球—测绘科学与技术]