摘要
以金沙江干热河谷区典型冲沟为对象,基于野外实测数据构建0.5 m×0.5 m格网冲沟DEM,对比分析了最邻近(NEAR)、双线性(BIL)及三次卷积(CUB)重采样方法对高程中误差(Er)、冲沟表面积(S)和体积(V)的影响.结果表明,DEM重采样到5.0 m×5.0 m过程中,BIL及CUB重采样DEM的高程中误差略小于NEAR;重采样过程中表面积比体积随格网分辨率变化敏感,2.5 m×2.5 m DEM表达的冲沟表面积降低为初始表面积的90%,4.0 m×4.0 m DEM冲沟的体积降低为90%.结果显示,对于形态复杂的冲沟,DEM重采样方法以BIL为首选,侧重宏观特征,如地形表面积等分析时约2.0 m×2.0 m格网较为适宜.
Compared with the different resampling methods affected by the elevation RMSE and other terrainfactors such as surface area（S）and volume（V）,this paper taken a typical gully in dry-hot valley of Jinshajiangriver as the research object. After the field surveying,a 0.5 m×0.5 m of resolution DEM was produced with arelatively small RMSE of 0.48 meter. Three resampling methods were used to produce 1.0 m×1.0 m,1.5 m×1.5 m,2.0 m×2.0 m,…,5.0 m×5.0 m DEMs. Then the elevation RMSE,S and V were calculated. The results showed thatthe BIL resampling method was the most suitable one according to the RMSE. When the S and V were investigated,it could be found that S was more sensitive than V when the grid cellsize changes. According to the results about S,it showed that 2.0 m×2.0 m DEM was suitable when it used to depict the roughness of the gully,while 4.0 m×4.0 mDEM maybe could used to calculate the erosion volume if there was no more higher quality DEM used.
作者
谭壮
李晓锋
徐亚莉
罗明良
Tan Zhuang Li Xiaofeng Xu Yali Luo Mingliang(Land ＆ Resources School,China West Normal University,Nanchong 637009,Sichuan China Geography and Environment School,Northwest Normal University,Lanzhou 730070,China)
出处
《河南科学》
2016年第11期1899-1902,共4页
Henan Science
基金
国家自然科学基金项目(41101348)
四川省教育厅自然科学重点项目(16ZA0168)
关键词
高程中误差
DEM
重采样
地形表面积
格网大小
金沙江
干热河谷
elevation RMSE
DEM
resampling methods
surface area
DEM grid cellsize
Jinshajiang river
dry-hot valley
