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针对滑坡临界雨量确定目前存在的问题,提出一种基于土壤侵蚀模型的滑坡临界雨量估算的新方法。该方法基本思路是:降雨引起土壤侵蚀,当土壤侵蚀达到一定强度时可诱发滑坡,因此利用土壤侵蚀模型可以推算滑坡临界雨量。以湖北省秭归县为例进行试验,从降雨-土壤侵蚀-滑坡的成灾机理入手,利用卫星资料、地理信息资料及降雨资料,计算降雨侵蚀力、土壤可蚀性、地形(坡长、坡度)、植被覆盖和土地利用类型等因子,基于USLE土壤侵蚀模型,计算滑坡发生时土壤侵蚀强度,通过分析多个滑坡个例,确定滑坡临界土壤侵蚀强度,再根据降雨侵蚀力与降雨量之间的关系,推算不同预警点滑坡临界雨量。相比以往仅仅分析灾情与降雨之间关系的传统方法,该方法有较为清晰的物理意义,实际业务中也易于实现,在滑坡预警预报中有较高实用价值。
Aiming at the existing problems in determining the critical rainfall of landslide, a new method of landslide critical rainfall estimation based on soil erosion model is proposed. The basic idea of this method is that rainfall causes soil erosion, and landslides can be induced when soil erosion reaches a certain intensity. Therefore, the critical rainfall of landslide can be calculated by using soil erosion model. Taking Zigui County in Hubei Province as an example, this paper starts from the mechanism of rainfall-soil erosion-landslide and uses satellite data, geographic information data and rainfall data to calculate rainfall erosivity, soil erodibility, topography ), Vegetation cover and land use types, the soil erosion intensity at landslide occurrence was calculated based on the USLE soil erosion model. Based on the analysis of multiple landslide cases, the critical soil erosion intensity of landslide was determined. Based on the relationship between rainfall erosivity and rainfall, The relationship between the projections of different warning landslide critical rainfall. Compared with the traditional method of analyzing the relationship between disaster and rainfall, the method has a clear physical meaning and is easy to be implemented in actual business. It has high practical value in landslide warning and forecasting.