An examination of the hydrological system of a sand dam during the dry season leading to water balances
An examination of the hydrological system of a sand dam during the dry season leading to water balances
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DOI：
10.1016/j.hydroa.2019.100035
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发表时间：
2019-06
影响因子：
4
通讯作者：
R. Quinn;K. Rushton;A. Parker
中科院分区：
文献类型：
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作者：
R. Quinn;K. Rushton;A. Parker
为了解决半干旱地区的水资源短缺问题，需要在降雨和径流流失到海洋之前将其收集并储存在当地。这可以通过使用沙坝来实现，沙坝包括在旱季横跨季节性河床建造的加固墙。然而，目前尚不清楚它们的主要用途是将水储存在也被困在它们后面的沙子中，还是促进含水层的补给。本文旨在回答这个问题，在肯尼亚的三个砂坝的水平衡的计算，量化的砂坝和周围的含水层系统之间的水量转移。水平衡的组成部分来自广泛的实地监测。通过沿着沉积砂长度方向安装的压力计监测水位，可以计算水力梯度，从而计算砂坝不同河段之间的横向流动。在一个沙坝中，水在整个旱季都在不断地增加，在一个沙坝中，水流失了，在第三个沙坝中，除了旱季早期，几乎所有的时间都在流失。总之，砂坝不应被视为孤立的蓄水结构。
To address water scarcity in semi-arid regions, rainfall and runoff need to be captured and stored locally before they are lost to the sea. This can be done using a sand dam which consists of a reinforced wall constructed during the dry season across a seasonal riverbed. However it is unclear whether their main utility is to store water in the sand that is also trapped behind them, or to facilitate aquifer recharge. This paper aims to answer this question by the calculation of a water balance in three sand dams in Kenya to quantify the amount of water transferred between the sand dam and the surrounding aquifer system. The components of the water balance were derived from extensive field monitoring. Water level monitoring in piezometers installed along the length of the sand deposits enabled calculation of the hydraulic gradient and hence the lateral flow between the different reaches of the sand dam. In one sand dam water was gained consistently through the dry season, in one it was lost, and in the third it was lost almost all the time except for the early dry season in the upper part of the trapped sand. In conclusion sand dams should not be treated as isolated water storage structures.