甘肃南部武都区滑坡危险性评价

Assessment of Landslide Hazard in Wudu of Southern Gansu Province

利用GIS技术分别与信息量模型和贡献权重模型结合,以甘肃南部武都区为研究区,选取高程、坡度、地质年代、河流缓冲区、土地利用和距离断层构造线距离6个评价因子进行滑坡危险性评价,得到基于2种评价模型的区划图。对比2种结果分析得出:从滑坡灾害点的分布情况看,2种模型均能较好地对研究区滑坡危险性进行分区,但基于贡献权重模型得出的结果显示,中、高和极高度危险区的面积占全区总面积的82.3%,略夸大了山区滑坡灾害的危险性。结合现场实际勘察结果表明:基于信息量模型得到的危险性评价结果更符合武都区的实际情况。因此,利用信息量模型与GIS技术结合对甘肃南部武都区滑坡灾害进行评价,相比贡献权重模型具有较高的准确性,为研究区滑坡的防灾减灾工作提供了参考价值。

GIS technology is combined with information value model and contribution weight model respectively to assess the landslide hazard in Wudu district of south Gansu Province. Elevation, slope gradient, stratum lithology, river buffer zone, land use, and distance to fault line arc selected as the assessment factors. Zoning maps are ob- tained based on the two models and comparison reveals that as shown from the distribution of landslide hazards, both models work well in landslide hazard zoning, but the results based on contribution weight model suggest that medium, high and very high risk zones together account for 82.3 % of the total area, which has slightly exaggerated the risk of landslides in mountainous areas. According to on-site investigation, the landslide hazard zoning based on information value model is more in line with the actual situation. Therefore it is accurate to combine information value model with GIS technology in landslide hazard assessment for South Gansu Province.