论文部分内容阅读
土壤水分状况是形成泥石流的关键性水文因素之一。本文以蒋家沟为研究对象,基于水分的物理循环过程并与半分布式水文分布模型TOPMODEL相结合,建立起土壤湿度逐日变化模拟模型。研究表明,流域的平均饱和度是土壤水分条件评估的较好的指标,结合蒋家沟流域2001年暴发的17场次的泥石流事件得到以下一些结论:(1)前期降水主要积累在地表以下约90cm土壤中;(2)65%的流域平均饱和度值是判断激发泥石流的前期土壤水分条件的临界值;(3)2001年蒋家沟流域暴发的17场次的泥石流中,以土体饱和启动为主要类型。本文所构造的模型能够比较好地模拟出流域内土壤湿度逐日变化情况并对激发泥石流的土壤水分条件作出适当的评估。
Soil water status is one of the key hydrological factors in forming debris flow. In this paper, taking Jiangjiagou as the research object, this paper establishes a simulation model of daily variation of soil moisture based on the physical circulation process of moisture and combining with semi-distributed hydrological distribution model TOPMODEL. The results show that the average saturation of the basin is a good indicator to evaluate the soil water condition. The following conclusions are drawn from the 17 episodes of debris flow events in the Jiangjiagou watershed in 2001: (1) Precipitation mainly accumulates about 90 cm below the surface (2) The mean saturation value of 65% of the watershed is the critical value for judging the pre-soil water condition that triggered the debris flow. (3) In 17 episodes of debris flow that occurred in Jiangjiagou watershed in 2001, The main type. The model constructed in this paper can simulate the daily variation of soil moisture in the basin and make a proper assessment of the soil moisture conditions that trigger the debris flow.