基于多期DEM数据的滑坡变形定量分析

摘要

Quantitative deformation analysis of the landslide is a difficult problem in landslide study.To reveal the deformation and evolution process of landslides in Heifangtai,the authors established the quantitative deformation analysis model of landslide based on multi-period DEM data by ArcGIS using four periods of topographic maps obtained respectively in 1977,1997,2001,and 2010.The deformation degree and rate of 32 landslides were calculated in stages at Heifangtai terrace in Yongjing,Gansu Province.Between 1977 and 1997,the average retrograde eroding velocity of landslide scarp was 4.47m/a.Between 1997 and 2001,the average retrograde eroding velocity of landslide scarp was 3.46m/a.Between 2001 to 2010,the average retrograde eroding velocity of landslide scarp was 1.10m/a.At the same time,the related formula for irrigation amount and landslide deformation degree was established,and the prediction of the development tendency of landslides was carried out.The calculation results show that the average retrograde distance of the landslide scarps will be 0.79m by 2015,and the retrograde distance will be reduced to 0.20m by 2020.%滑坡的定量变形分析是滑坡研究中的难点问题.为揭示黑方台灌区滑坡的变形演化过程,借助1977年、1997年、2001年和2010年4个时期测制的地形图资料,以ArcGIS为平台,建立了基于多期DEM数据的滑坡变形定量分析模型,并对黑方台塬边32处滑坡分阶段进行了变形量与变形速率计算.1977-1997年,滑坡后壁后移侵蚀速率平均为4.47m/a;1997-2001年,后移侵蚀率平均为3.46m/a;2001-2010年,后移侵蚀率平均为1.10m/a.同时建立了灌溉量与滑坡变形量的相关关系式,并对滑坡的变形演化趋势进行了预测,到2015年,滑坡后壁后移距离平均为0.79m,到2020年,滑坡后壁后移距离可减少到0.20m.