Abstract：Landslide hazard assessment is necessary for disaster management and planning in dam projects. This paper presents a geographical information systems/remote sensing-aided procedure for landslide hazard mapping at a regional scale around the Qinggan River of the Three Gorges，China，where most of landslides are active in dip slopes. A landslide inventory is carried out based on field investigations and aerial photo interpretation，while another data set of environmental factors is constructed，such as geological and topographic thematic maps，lithology and vegetation maps. The factors contributing to landslide occurrence such as altitude，slope and flow accumulation，are derived from Digital Elevation Models，and rock strata is also extracted from geological map，vegetation index from satellite images of Landsat TM bands 2/3/4. Quantitative geometric alignment relationships between strikes of slopes and strata are established by TOBIA index，and a method of generalized likelihood ratio is then utilized to analyze the relationships between landslide occurrence and environmental factors，such as lithology，slope angle，aspect，flow accumulation and vegetation，etc. Based on the database，the casual factors，which make possible contribution to landslide occurrence，are combined into a binary logistic regression model，and then the landslide probabilities are calculated by cell to cell. The results from the logistical regression model coincides well with the previous landslide occurrence.
