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题名	汶川地震区土体降雨入渗及流域产汇流研究—以都江堰龙溪河流域为例
作者	宋国虎
学位类别	硕士
答辩日期	2013
授予单位	中国科学院研究生院
授予地点	北京
导师	崔鹏
关键词	汶川地震 入渗 产流 人工降雨试验 土地利用 降雨径流 模拟
学位专业	岩土工程
中文摘要	汶川地震产生强烈的地表扰动和大面积植被毁灭性破坏，形成了大量崩塌滑坡体，致使流域内土壤降雨入渗和流域产流规律发生变化。震后几个雨季山洪泥石流活动的事实已经证明未来很长一段时间内地震灾区暴雨山洪泥石流的发生将更加频繁。目前，汶川地震扰动对流域产汇流的影响只是一些学者定性的理论分析，而很少有学者通过野外试验，用具体的数据去验证这些理论分析。 本研究选取汶川地震灾区都江堰龙溪河流域为研究对象，在广泛查阅国内外文献资料和野外调查的基础上，选取流域内不同土地利用类型的土体，测定不同土地利用类型下土体的入渗率；选取典型滑坡体进行不同雨强下的降雨入渗产流试验，分析滑坡体的降雨入渗及产流规律；结合龙溪河内的实测降雨径流资料分析震后龙溪河的降雨径流规律；最后用HEC-HMS模型对龙溪河的降雨径流进行参数率定和模拟验证。通过研究，得出的初步结论如下： （1）研究区的稳定下渗率：流域内不同土地利用类型土体的稳定入渗率按大小依次为林地、草地、耕地、泥石流堆积体、滑坡体、裸地，其值分别为：0.3151mm/min，0.2983mm/min，0.2834mm/min，0.1932mm/min，0.1683mm/min，0.0739mm/min。滑坡体和裸地的稳定入渗率远小于其他土地利用类型土体。 （2）研究区内典型滑坡体的入渗和产流过程：对于不同雨强的降雨过程，坡地不同深度的土壤含水量初始上升的时间、土壤达到饱和的时间以及产流滞时与降雨强度存在明显的幂函数关系。对于试验滑坡体来说，15-30cm深处土壤细颗粒含量较高，堵塞水分运移通道，入渗率较小，且控制着整个剖面的入渗率。研究区主要以表层蓄满产流方式为主，而在暴雨情况下，产生地表超渗产流和深层地下径流。研究区降雨丰沛，且降雨主要集中在夏季，土体缺水量很少，很容易达到饱和。 （3）龙溪河的降雨径流特征：汶川地震后龙溪河流域内产生大量崩塌滑坡体，通过实地调查和遥感解译，研究区内崩塌滑坡体面积11.67km2，占整个研究区面积的30.36%。研究区的几场天然降雨的径流系数在21.95%~33.16%之间，径流系数都比较小，随着降雨强度的增大而增大。同时，径流过程不仅与雨强有关，而且与降雨的时间分布也有关。利用HEC-HMS模型模拟龙溪河径流过程与实测的降雨径流过程基本一致，洪峰流量和径流总量的误差小于20%，均在允许范围之内，模拟径流过程的确定性系数DC值达到乙等水平，模型参数可用于震后龙溪河流域的水文预报。
英文摘要	The 5.12 Wenchuan Earthquake generated strong surface disturbance and destruction of large areas of vegetation, which triggered a large number of landslides, resulting in soil infiltration and watershed runoff yield rule change.After the earthquake,in a few rainy season flash flood and debris flow activities facts have proved that torrential rain of flash flood and debris flow will occur more frequently in the earthquake-stricken areas in the future for a long period of time. At present, the earthquake disturbance Rainfall-runoff just some scholars qualitative theoretical analysis, and few scholars through field trials, with the specific data to verify these theories. Taking the earthquake-hit Dujiangyan Longxi River Valley for the study, based on extensively reviewed the literature data and field survey, different types of land use in the watershed soils had been selected, and there infiltration rate had been determined; to analysis of landslide rainfall infiltration and runoff law, typical landslide had been chosen with different rainfall intensity rainfalls for infiltration and runoff test; Longxi River measured rainfall-runoff data has been used to analysis Longxi River rainfall runoff law after the earthquake;After that,HEC-HMS model of the Long River has been established and rainfall runoff parameter calibration and simulation verification has been done. The main research work and its achievements of this study involves several aspects as follows: (1)Stable infiltration rate in the study area: The results show that the saturated stable infiltration rates of different type soils such as forest land, grassland, cultivated land, debris flow fan, landslide land and bare land are 0.3151 mm/min, 0.2983 mm/min, 0.2834 mm/min, 0.1932 mm/min, 0.1683 mm/min and 0.0739 mm/min respectively. The landslide and bare soil infiltration rate is much smaller than the other land use types of soil. (2)Infiltration and runoff process of typical landslide in the study area: For different rainfall intensity of rainfall, the initial rise time of the different depths of soil moisture , the time of soil becomes saturated and the surface runoff lag time is of a significant power reduction function relationship exists. For the experimental landslide , compared with the upper and lower ,15-30cm deep soil has a smaller porosity, and this smaller infiltration controls the entire cross-sectional view of the infiltration rate.Stored-full runoff is the main runoff yield mechanism in the study area.But in rainstorms, excess seepage of surface and deep underground runoff occur at the same time. Under the heavy rain,Horton model can be used to describe the infiltration process.When the rainfall intensity is 52 mm/h, the infiltration achieve stability within 10 minutes after the runoff occured.Abundant rainfall in the study area, and the rainfall is mainly concentrated in the summer. It is easy to reach saturation because the soil water deficit rarely. (3) Rainfall-runoff characteristics of Longxi River Basin: A large number of landslides produced in Longxi River Basin after the earthquake, interpreted by field survey and remote sensing, the collapse and landslide is an area of 11.67km2,accounting for 30.36% of the entire study area. The study area with a relatively small runoff coefficient range from 21.95% to 33.16% in several natural rainfall runoff and increases with the increasing rainfall intensity. At the same time, the rainfall runoff process is not only related to rainfall intensity but also the time distribution of rainfall.Longxi River runoff process using HEC-HMS model simulation is basically same with the measured rainfall runoff process, and the peak flow and runoff volume error is less than 20%, are within the allowable range. The simulated runoff process certainty coefficient DC value B can be used in the the Longxi River Basin hydrological forecasts.
公开日期	2014-06-20
内容类型	学位论文
源URL	[http://ir.imde.ac.cn/handle/131551/6966]
专题	成都山地灾害与环境研究所_山地灾害与地表过程重点实验室
推荐引用方式 GB/T 7714	宋国虎. 汶川地震区土体降雨入渗及流域产汇流研究—以都江堰龙溪河流域为例[D]. 北京. 中国科学院研究生院. 2013.

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