An analytical study on artesian flow conditions in unconfined‐aquifer drainage basins
An analytical study on artesian flow conditions in unconfined‐aquifer drainage basins
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DOI：
10.1002/2015wr017104
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发表时间：
2015-10
影响因子：
5.4
通讯作者：
Jun‐Zhi Wang;Xiaowei Jiang;L. Wan;A. Wörman;Heng Wang;Xu-sheng Wang;Hailong Li
中科院分区：
文献类型：
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作者：
Jun‐Zhi Wang;Xiaowei Jiang;L. Wan;A. Wörman;Heng Wang;Xu-sheng Wang;Hailong Li
虽然有报告指出，自流威尔斯井可以地形控制，但没有定量研究承压含水层中的自流条件。在这项研究中，地下水位，这有一个较低的振幅比陆地表面，从地形阻尼，并作为边界条件，以获得一个单一的流系统的单元流域的水头的解析解。术语承压水头的定义是描述自喷威尔斯井的状况。具有正承压水头的带称为承压带，具有负承压水头的带称为非承压带。最大承压水头和承压带的大小随阻尼因子和各向异性比的增大而增大，随盆地宽深比和渗透系数的深度衰减指数的增大而减小。在沟谷附近，承压水头随深度增加，在分水岭附近，承压水头随深度减小，其变化率受衰减指数和各向异性比的影响。最后，以鄂尔多斯高原某小流域自喷威尔斯井的分布和钻孔不同深度的承压水头测量结果为例，说明了理论分析结果的正确性。利用承压水头随深度的变化来估计各向异性比和衰减指数。这项研究为分析流域尺度地下水流开辟了一扇新的大门。
Although it has been reported that flowing artesian wells could be topographically controlled, there is no quantitative research on artesian flow conditions in unconfined aquifers. In this study, the water table, which has a lower amplitude than the land surface, is damped from the topography and used as the boundary condition to obtain the analytical solution of hydraulic head of a unit basin with a single flow system. The term artesian head is defined to characterize the condition of flowing artesian wells. The zone with positive artesian head is called artesian zone while with negative artesian head is nonartesian zone. The maximum artesian head and the size of artesian zones are found to increase with the damping factor and the anisotropy ratio, and decrease with the ratio of basin width to depth and the depth‐decay exponent of hydraulic conductivity. Moreover, the artesian head increases with depth nearby the valley and decreases with depth near by the divide, and the variation rates are influenced by the decay exponent and the anisotropy ratio. Finally, the distribution of flowing artesian wells and the artesian head measurements in different depths of a borehole in a small catchment in the Ordos Plateau, Northwestern China is used to illustrate the theoretical findings. The change in artesian head with depth was used to estimate the anisotropy ratio and the decay exponent. This study opens up a new door to analyze basin‐scale groundwater flow.