Modelling the potential impacts of groundwater hydrology on long‐term drainage basin evolution
Modelling the potential impacts of groundwater hydrology on long‐term drainage basin evolution
复制标题
模拟地下水水文学对长期流域演化的潜在影响
DOI：
--
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
J. Niemann
中科院分区：
文献类型：
--
作者：
Xiangjiang Huang;J. Niemann
河流侵蚀过程是由地表水排放驱动的，水排放是由地表径流和地下水排放产生的。尽管地下水在长期景观演化问题中经常被忽视，但地下水位控制着邓恩径流产生的模式，地下水排放对暴雨流有显着影响。在本次分析中，我们通过修改广泛使用的景观演化模型以包括更详细的流域水文表征，研究地下水运动在长期流域演化中发挥的作用。降水是由随机过程产生的，并且使用指定的渗透能力将降水分配在地表径流和地下水补给之间。地下水流通过动态二维 Dupuit 方程模拟，适用于具有不规则底层不透水层的无承压含水层。该模型适用于宾夕法尼亚州的一个实验集水区 WE-38 流域，因为 60-80% 的排放来自地下水，并且可以获得大量的水文和地貌信息。首先校准水文模型以匹配观测到的水流，然后使用组合的水文/地貌模型来模拟具有不同渗透能力的场景。模拟结果表明，流域可划分为三个具有明显水流生成特征的区域，流域的不同部分可发生不同的地貌有效事件。在很长一段时间内，地下水排放量大的情况往往会改变地形，从而促进地下水排放并抑制邓恩径流。版权所有 © 2006 约翰·威利父子有限公司
Fluvial erosion processes are driven by water discharge on the land surface, which is produced by surface runoff and groundwater discharge. Although groundwater is often neglected in long‐term landscape evolution problems, water table levels control patterns of Dunne runoff production, and groundwater discharge can contribute significantly to storm flows. In this analysis, we investigate the role that groundwater movement plays in long‐term drainage basin evolution by modifying a widely used landscape evolution model to include a more detailed representation of basin hydrology. Precipitation is generated by a stochastic process, and the precipitation is partitioned between surface runoff and groundwater recharge using a specified infiltration capacity. Groundwater flow is simulated by a dynamic two‐dimensional Dupuit equation for an unconfined aquifer with an irregular underlying impervious layer. The model is applied to the WE‐38 basin, an experimental catchment in Pennsylvania, because 60–80 per cent of the discharge is derived from groundwater and substantial hydrologic and geomorphic information is available. The hydrologic model is first calibrated to match the observed streamflows, and then the combined hydrologic/geomorphic model is used to simulate scenarios with different infiltration capacities. The results of this modelling exercise indicate that the basin can be divided into three zones with distinct streamflow‐generating characteristics, and different parts of the basin can have different geomorphic effective events. Over long periods of time, scenarios in which groundwater discharge is large tend to modify the topography in a way that promotes groundwater discharge and inhibits Dunne runoff. Copyright © 2006 John Wiley & Sons, Ltd.