基于SINMAP模型的延安市滑坡危险性区划

目的]对陕西省延安市开展滑坡危险性区划研究,为延安地区乃至黄土高原区滑坡危险性区划以及监测预警提供科学依据。方法]在野外调查的基础上以滑坡触发因素为切入点,建立了基于SINMAP滑坡危险性评价模型,定量评价了不同降雨级别下滑坡区域面积的迁移与转化规律。结果]降雨雨强从5 mm/h升至200 mm/h,不稳定性区域内比例分别增加6.48%和6.44%,极稳定区域面积所占比例和所占滑比例均值高达46.79%和51.33%;同时潜在不稳定区面积所占比例在5.04%～17.31%之间浮动,所占滑坡比例在5.14%～15.43%之间浮动。结论]斜坡表层土壤水分、湿度区域面积随着降雨量的增大逐渐增加,区内稳定区域正向失稳区域转化。

Risk Zoning of Landslide Based on SINMAP Model in Yan'an City

Objective] Landslide hazard zoning research in Yan''an City of Shaanxi Province was carried out in order to provide a scientific basis for regional landslide prevention and reduction in Yan''an City and the Loess Plateau region.Methods] Starting with the triggering factors of landslides in Yan''an City, and coupling with field survey, we established regional risk assessment model for shallow landslide using SINMAP model. We analyzed the risk areas of regional landslide, and quantitatively evaluated the migration and transformation of the landslide area under different rainfall conditions.Results] With the increase of rainfall intensity from 5 mm/h to 200 mm/h, the proportions in the unstable region increased by 6.48% and 6.44% and the proportions in the stable region were always the highest, with an average of 46.79% and 51.33%. Meanwhile, potential unstable region may be transformed into unstable and very unstable region; area proportions varies between 5.04% and 17.31% and landslide proportions varies between 5.14% and 15.43%.Conclusion] With an increase in rainfall, surface shallow soil moisture and humidity area increased, and extended to the ridge and gentler slopes unit. The transition from stable region to unstable region is taking place in the region.