滑坡和泥石流灾害与环境因子的关系

明确滑坡和泥石流灾害发生百分率与地学因子间的关系，对相关预报和危险度评价研究具有重要意义.基于全国18431个滑坡和泥石流灾害点的定位信息，结合1 km×1 km栅格内6个环境因子（高程、高差、坡度、坡向、植被类型、植被覆盖度）的空间分布数据，利用频率比数分析方法分析了这些环境因子与滑坡和泥石流灾害的关系.结果表明：滑坡和泥石流更多地分布于我国三大自然阶梯的第1和第2过渡带中海拔较低的地区；1 km×1 km栅格内高程差为300 m时，滑坡和泥石流灾害发生的可能性最大；当坡度为30°时，滑坡和泥石流灾害爆发的可能性最大；山区林地和坡耕地是最易发生滑坡和泥石流的两个地类；植被覆盖度在80%～90%时，滑坡和泥石流灾害的发生频率最高.

Relations of landslide and debris flow hazards to environmental factors.

To clarify the relations of landslide and debris flow hazards to envir onmental factors is of significance to the prediction and evaluation of landslid e and debris flow hazards. Base on the latitudinal and longitudinal information of 18431 landslide and debris flow hazards in China, and the 1 km×1 km grid dat a of elevation, elevation difference, slope, slope aspect, vegetation type, and vegetation coverage, this paper analyzed the relations of landslide and debris f low hazards in this country to above-mentioned environmental factors by the ana lysis method of frequency ratio. The results showed that the landslide and debri s flow hazards in China more occurred in lower elevation areas of the first and second transitional zones. When the elevation difference within a 1 km×1 km gri d cell was about 300 m and the slope was around 30 degree, there was the greates t possibility of the occurrence of landslide and debris hazards. Mountain forest land and slope cropland were the two land types the hazards most easily occurre d. The occurrence frequency of the hazards was the highest when the vegetation c overage was about 80%〖KG-*2〗-〖KG-*7〗90%.