GIS技术在三峡库区滑坡灾害研究中的应用

APPLICATION OF GIS TECHNOLOGY IN THE PRIMARY STUDY ON LANDSLIDE HAZARDS IN THE THREE GORGES RESERVOIR AREA, CHINA

对三峡库区选定的研究区域,建立地质、地形等滑坡因子空间数据库和滑坡空间分布数据库(比例尺均为1:10000),利用GIS技术对滑坡和各影响因子相关性进行了统计分析。计算得出滑坡发生的主要影响因子类属:Q4、J1x,J1z、S岩性岩组;90m以下、90～135m和135～175m三个高程带;15～20m局部高差;10°～15°、15°～20°和20°～25°坡度;北向、南向和西北向方向和1～1曲率范围。研究的结果是进行滑坡易发性评价的基础,可以帮助指导库区滑坡灾害管理、土地利用等。

Geographical Information System(GIS)has been widely used in the field of landslide studies because of its powerful spatial analysis and spatial database management. The authors review statistical relationship between landslide occurrence and static and dynamic variables using powerful function of GIS. To apply the statistical method, a spatial database with consideration of static factors was designed and constructed. These data are available either as a paper map or as a digital map. A digitized map of landslide location and boundaries was produced from the catalogue about regional landslides and 1:10 000 distribution maps; topographical and geological data (1:10 000-scale paper maps) are collected, digitized and manipulated into a spatial database using ArcGis GIS. We used 7 landslide triggering factors to analyze the relation landslide spatial distribution and their contributing factors. The influence of pertinent factors on the occurrence of landslides is Q-4、J-{1x}、J-{1z}、S Lithology formation; 90m, 90～135 m and 135～175 m elevations; 15～20 m local relief; 10°～15°、15°～20° and 20°～25° slope; N,S and WN aspect and -1～1 curvature. The GIS was used to analyze efficiently the vast amount of data, and statistical programs were used to maintain specificity and accuracy. The results can be used to reduce associated hazards, and to plan land use and construction.