重庆市地形起伏度的提取及其在水土流失评价中的应用 冉红+黎武+杨晓+徐珍+贺春明+蒋婷摘 要：该文基于90m分辨率的SRTM DEM数据，采用窗口分析法提取重庆市的地形起伏度，通过均值变点法确定提取重庆市地形起伏度的最佳统计单元为9090，基于最佳统计单元提取出地形起伏度，然后完成重庆市地形起伏度的分级和制图，最后利用地形起伏度对重庆市水土流失状况进行评价结果表明：重庆市地形起伏度整体上以大起伏为主，所占比例为42.66%，其次是极大起伏度，比例为30%地形起伏度与水土流失在空间分布上具有一致性，即水土流失程度随地形起伏度的增加而加重，北部大巴山、东部巫山以及南部大娄山区等整体起伏度较大，水力侵蚀以重度以及强烈侵蚀为主，水土流失最为严重西部平行岭谷区及盆周山地地形起伏度则很和缓，水土流失较轻微由此可见，地形起伏度的分析研究对于区域水土流失评价具有重要意义关键词：地形起伏度；水土流失；均值变点法；重庆市P283 A 1007-7731（2017）09-0092-04Abstract：Based on the 90m resolution SRTM DEM data，using the Windows analysis to extract the relief amplitude of Chongqing City. Through the mean of change-point method，it determines the optimum statistical unit is 9090 grid unit. Then extract the relief amplitude of Chongqing City which is basing on the optimum statistical unit. Next，the classification and mapping of Chongqing City relief amplitude grade was completed. Finally，assessing the situation of soil and water loss by using relief. The result show that，the relief amplitude of Chongqing City dominated by big relief，which is accounted for 42.66 percent. The next is great relief amplitude，which is accounted for about 30 percent. The space distribution of water and soil loss have much consistency in the relief amplitude，namely the degree of water and soil loss aggravate as the relief amplitude increase. The overall relief amplitude of the DaBa Mountain which is located in the North of Chongqing，the Wu Mountain which is located in the east of Chongqing，and the Daloushan Mountain is located in the South of Chongqing are larger. The water erosion is mainly made of severe erosion and violent erosion，the water and soil erosion is most seriously. The relief amplitude of the Paralleled Ridge-valley which is located in the west and the Mountain regions around Sichuan Basin is gentle. Thus，the analysis of relief amplitude have important meaning for assessing the water and soil loss.Key words：Relief amplitude；Water and soil loss；The mean of change-point method；Chongqing City水土流失是指由各種外营力（如水力、风力、重力、冻融等）引起的水土资源和土地生产力的破坏和损失，包括土地表层侵蚀和水的损失的现象，也称为水土损失[1]。
水土流失是导致土地退化的重要原因之一，而我国是世界上水土流失最严重的国家之一，截至20世纪末，我国水土流失面积达356万km2，占国土面积的37%，且目前仍呈增长趋势水土流失研究按照研究尺度的不同可划分为3个层次：区域、小流域和坡面研究，其中区域水土流失研究是土壤侵蚀研究的重要内容[2]但目前国内外关于水土流失的研究主要集中在小流域和坡面等小尺度范围，而对区域水土流失的研究相对较少重庆市是我国严重水土流失的地区之一，据统计，2014年重庆市水土流失总面积为3.08万km2，占重庆市土地总面积的37.34%，水土流失已成为重庆市经济发展和社会发展的重要的限制因素之一区域水土流失评价的重要基础工作就是对多种空间尺度上的地形因子进行选择、提取和应用地形起伏度作为重要的地形因子能够反映区域地表起伏特征地形的起伏是导致水土流失最直接的原因，使用地形起伏度来评价水土流失，不仅具有数学意义，还具备土壤侵蚀和地貌学意义[3]因此，对重庆市地形起伏度进行提取，然后用其评价水土流失，对重庆市水土流失宏观分析与趋势预测以及水土保持工作具有重要意义 -全文完-。