【摘要】 基于黄土丘陵沟壑区1979和1993年两期航片和地形图数据,采用数字影像测量方法生成数字正射影像图和数字高程模型,以地理信息系统为手段,研究了黄土丘陵沟壑区的一条沟谷在中尺度时间上的面积及深度变化,并对该变化的空间差异以及关键影响因子进行了分析.结果表明:1979—1993年间,研究区沟头前进了8.5m,沟谷内的侵蚀模数为481.28t.hm-2.a-1;沟谷中部的新侵蚀面积和侵蚀率最高,侵蚀过程活跃,存在的侵蚀风险最高;沟头前进活跃,坡度变陡,存在较高的侵蚀风险;出水口以沉积过程为主,其侵蚀面积小于沉积面积,沟的深度和沟谷坡度变小,侵蚀风险较低.更多还原

【Abstract】 Based on the aerial photographs in 1979 and 1993,and by using geographical information system(GIS)techniques,the digital elevation models(DEM)and digital orthophoto map(DOM)were constructed from the geomorphic changes in a chosen gully in the Loess hilly-gully area,and the spatial difference of the changes and their key affecting factors were analyzed.The results indicated that from 1979 to 1993,the gully head advanced actively(with a length of 8.5 meters and an erosion rate of 481.28 t·hm-2·a-1),and the slope tended to become steeper,exhibiting a high erosion risk.The middle part of the gully had the largest newly eroded area and the highest erosion rate,and the erosion process was quite active,with the highest erosion risk.The water outlet was primarily endowed with deposition formation,whose eroded area was smaller than its deposition area,and the gully depth and slope were becoming less,with a lower erosion risk.更多还原