摘要
利用小集水区生态水文学模型-Topog 模型对雷州半岛桉树人工林纪家示范小集水区进行了地形分析和静态水文学模拟。地形分析表明,该集水区地表较为平坦,集水区总面积为0.63 km2,夏季、冬季与春(秋)分平均太阳辐射值分别为44 MJ·m-2·d-1、25 MJ·m-2·d-1 和34 MJ·m-2·d-1。在考虑太阳辐射影响与不考虑太阳辐影响两种情况下进行了集水区土壤含水量指数(WI)静态模拟。设定不同的静态壤中流参数值,Topog 模型模拟结果表明,静态壤中流越大,在集水区内高WI 的分布范围越大,也即土壤含水量越高。在考虑太阳辐射影响的条件下,分别设置不同的土壤导水率(T)、地表阴蔽系数(Es)、平均降雨量(R)进行了模拟。模拟结果表明,WI 分布依各参数的不同而变化。T 越大,在集水区内的WI 重新分布越快;T 越小,在集水区内WI 趋向于平均分布。Es 越大,集水区土壤所保持的含水量越高。集水区WI 随R 增大而有升高趋势。
Many hydrological characteristics of a catchment can be inferred from its topography. The eco-hydrological model, Topog, uses a sophisticated analysis of topography to describe the hydrological characteristics of a catchment in detail. This paper describes an integrated terrain analysis and steady state hydrological modelling study of a small forest catchment on Leizhou Peninsula, southern China using Topog. The terrain analysis was based on a DEM （digital elevation model） of the central part of the peninsula including the upper valley of the Nandu River. The basic hydrologic characteristics defining the Jijia catchment were catchment boundary, high points and saddles, calculated ridges and streams, and an element network separating the catchment into a large number of relatively uniform units for modelling. The topographic attributes of each element were calculated automatically, including slope, aspect, upslope contributing area and potential incident solar radiation. The slope of the catchment was relatively low： the difference between slopes of most elements was in the range of 2.8-5.7 degree, or less than 2.8 degree. The general description of the Jijia catchment provided by Topog included total catchment area of 0.63 km^2 and average amount of incident radiation of 44, 25, and 34 MJ. m^-2.d^-1 for summer, winter and equinoxes, respectively. The catchment convergence index and steady-state wetness indices （WI） of the elements of the Jijia experimental catchment with and without solar radiation-weighting were also obtained. From steady-state drainage flux modelling, we obtained a distribution of WI across the catchment. By setting different parameter values of uniform drainage flux, the mapped simulations of WI over the catchment indicated that the bigger the uniform drainage flux was, the higher the WI would be.We modelled a radiation-weighted drainage index at different values of uniform transmissivity （T）, different shaded soil fraction （Es）, and different uniform rainfall （R）. The
出处
《生态环境》
CSCD
北大核心
2005年第5期700-705,共6页
Ecology and Environmnet
基金
国家重点基础研究发展计划项目(2002CB1115)
中国科学院重大项目(KZCX1-SW-01-01A3)
中国科学院重要方向项目(KSCX2-SW-120)
中澳合作基金项目(FST97/77)
韶关学院博士启动基金资助(340222
3140375)
