汶川地震松散堆积体坡面侵蚀土壤水动力学机理研究

Earthquake loose deposits in Wenchuan area generate massive soil erosion, which seriously influences the ecological system recovery and threatens the production and livelihood security of the localities. Loose deposits generated on May 12th 2008 are used for on-site investigation of soil spatial distribution characteristics, to study the vertical distribution regularity of the variation patterns of physical properties（bulk density, rock contents, partical size etc）. On-site and laboratory simulated infiltration experiments are to be established to investigate infiltration property of earthquake loose deposits, so as to understand the relationship between the soil characteristics and its hydraulic characteristic parameters. On-site and laboratory simulated ranfall experiments are to be established to investigate the vertical distribution migration law between concentrated water flow and subsurface flow of earthquake loose deposits, so as to understand the mechanism of earthquake loose deposits erosion hydrodynamic. Mechanism -based hydrodynamic model for earthquake loose deposits erosion is to be developed based on the understanding of earthquake loose deposits erosion hydrodynamic process. Collected data of runoff in earthquake area are used to estimate model parameters and to validate the mechanism -based hydrodynamic models. The study aims to predict earthquake loose deposits erosion hydrodynamic mechanism so as to service the safety of ecological system and scientific basis for soil erosion on earth quake area.

汶川地震松散堆积体在降雨和径流的作用下产生严重的土壤侵蚀，严重影响震区生态环境恢复，威胁生产生活安全。以汶川地震松散堆积体为研究对象，分析土壤组成物质剖面分层结构特征，研究堆积体土壤容重、土石比例和碎石粒径等参数在剖面上的垂直分布规律；通过原位入渗和室内土柱模拟入渗试验，研究堆积体土壤剖面水分入渗性能垂直分布规律，获取堆积体土壤性质与其土壤水力学参数的定量关系；通过原位和室内模拟降雨试验，研究堆积体坡面径流和壤中流垂直分布运移规律，揭示堆积体地表径流和壤中流共同作用下土壤水动力学机理，建立堆积体土壤水动力学模型，用现场试验和监测数据，获取模型参数并验证模型。为震区生态水文安全和土壤侵蚀预报提供科学依据。