摘要
梯田地表作为一种特殊的经人工深度影响的地貌形态,目前已成为在山丘地区具有经济效益和生态效益的土地资源。但是在当前强化推进土地资源管理数字化,信息化的今天,对梯田的数字化表达以及分析还存在欠缺。本研究通过对数据的改造,构建出顾及梯田的DEM,并从原始DEM与梯田DEM的剖面结构特征、高程特征以及地形因子特征等方面进行了对比分析。结果表明:(1)基于真实田坎构建的梯田DEM,可较为准确且直观地反映梯田地形的特征。(2)与原始DEM相比,加入梯田信息后,梯田DEM高程剖面图总体呈阶梯式分布,转折部位明显,且基于梯田DEM提取的坡度、坡长、LS因子值明显减小,反映修建梯田后地形因子的变化,对进一步定量分析土壤侵蚀以及水土流失具有重大意义。
As the special and artiticial micro topograpny, terlelceb Ha j economic and ecological benefits in the Loess Plateau. However, most existing DEMs hardly satisfy the reali- zation of terrace terrain, and partial artificial landform in{ormation is lost. In this paper, we choose terraces in a basin in Ansai County as the case study area, the materials include DEM of Ansai （its scale is 1 ： 10 000, resolution is 5 m） and a remotely sensed image with a resolution of 2. 5 m. Based on the improved rapid modeling method for terrace digital elevation model, we adopt the actual ridge-based method to construct the DEM with terraces information （T-DEM） by integrating with high resolution remote sensing image. Using Spatial Analyst Module of ArcGIS and LS-TOOL, topographic features and terrain factors （slope, slope length and LS factor） were extracted from Original DEM and T-DEM, respectively. The results show that： （1） T-DEM reflects terrace terrain accurately and intuitively; （2） in comparison with the Original DEM in sample region, profile features of elevation extracted by T-DEM distribute like a ladder were more consistent with the real topographic features; meanwhile, slope, slope length and LS factor extracted by T-DEM are smaller; more precisely, the average of slope decreased by almost a half and its range increased; the range of slope length reduced obviously and the average of slope decreased; LS is reduced by 90%. In conclusion, terraces play an important role in DEM-based terrain analysis. This research has the significant meaning for evaluating soil erosion.
出处
《水土保持研究》
CSCD
北大核心
2017年第4期32-37,45,共7页
Research of Soil and Water Conservation
基金
国家自然科学基金"梯田对坡度坡长因子的扰动特征研究"(41271284)
