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SCI论文目录 |
雷州桉树人工林小集水区地形分析与静态水文学模拟(英文) |
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出 版 社:生态环境 |
发表时间:2005 |
台 站:
鼎湖山森林生态系统定位研究站
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作 者:黄志宏 周国逸 周光益 MORRIS Jim SILBERSTEIN Richard 王旭 |
点 击 率:5718 |
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关 键 字:桉树人工林 Topog 模拟 土壤含水量指数 雷州半岛 |
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。 |
关 键 字(英文):eucalyptus plantations Topog modelling wetness index Leizhou Peninsula |
摘 要(英文):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 km2 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 result illustrated that the mapped distribution of WI varies as a consequence
of these different data inputs. The distribution of WI was strongly affected by T values which indicated that soil wetness
within some stream zones might extend more widely, given a bigger T value. Conversely, lower values of T resulted in more uniform
spatial distribution of WI over the catchment. Modelled results also varied with shaded fraction, which indicated that a small increase
in solar radiation would result in spatially different distribution of soil moisture content over the catchment. Finally, we made a comparison between a set of uniform rainfall values and found that Topog predicted the expected trend that soil moisture within the
catchment increased with increasing uniform rainfall values. |
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雷州桉树人工林小集水区地形分析与静态水文学模拟英文.PDF |
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