Is annual recharge coefficient a valid concept in arid and semi-arid regions?
Is annual recharge coefficient a valid concept in arid and semi-arid regions?
复制标题
年补给系数在干旱和半干旱地区是一个有效的概念吗？
DOI：
10.5194/hess-21-5031-2017
复制
发表时间：
2017-10-06
影响因子：
6.3
通讯作者：
Li, Wei
中科院分区：
文献类型：
--
作者：
Cheng, Yiben;Zhan, Hongbin;Li, Wei
土壤深层补给(大于2 0 0 cm)是干旱半干旱地区水分循环的重要组成部分。DSR的定量监测对干旱半干旱地区水资源评价和水量平衡研究具有重要意义。本研究以鄂尔多斯盆地中国地区毛乌素沙地东缘典型裸地为例，阐述了一种新的蒸渗仪测定DSR的方法，以检验研究区年补给系数的有效性，其年补给效率为年DSR与年总降雨量之比。于2013-2015年对研究区流动沙丘下的降水和DSR进行了定位监测。结果表明，用年补给系数来估算干旱半干旱地区裸露沙地的DSR是值得怀疑的，并可能导致相当大的误差。结果表明，除总降水量外，这几个地区的降水量与自发性强降水事件(降水量大于10 mm)密切相关。这项研究表明，一次强降水事件中高达42%的降水可以转化为 。在观测期内，最大年降水量可占年降水量的24.33 %。该研究为干旱半干旱沙区地下水资源管理和生态恢复提供了一种可靠的估算方法。这也为利用年补给系数计算干旱半干旱地区的DSR提供了有力的证据。研究表明，DSR与强降水事件密切相关，而不是与年平均降水量和降水类型密切相关。
Deep soil recharge (DSR) (at depth greater than 200 cm) is an important part of water circulation in arid and semi-arid regions. Quantitative monitoring of DSR is of great importance to assess water resources and to study water balance in arid and semi-arid regions. This study used a typical bare land on the eastern margin of Mu Us Sandy Land in the Ordos Basin of China as an example to illustrate a new lysimeter method of measuring DSR to examine if the annual recharge coefficient is valid or not in the study site, where the annual recharge efficient is the ratio of annual DSR over annual total precipitation. Positioning monitoring was done on precipitation and DSR measurements underneath mobile sand dunes from 2013 to 2015 in the study area. Results showed that use of an annual recharge coefficient for estimating DSR in bare sand land in arid and semi-arid regions is questionable and could lead to considerable errors. It appeared that DSR in those regions was influenced by precipitation pattern and was closely correlated with spontaneous strong precipitation events (with precipitation greater than 10 mm) other than the total precipitation. This study showed that as much as 42 % of precipitation in a single strong precipitation event can be transformed into DSR. During the observation period, the maximum annual DSR could make up 24.33 % of the annual precipitation. This study provided a reliable method of estimating DSR in sandy areas of arid and semi-arid regions, which is valuable for managing groundwater resources and ecological restoration in those regions. It also provided strong evidence that the annual recharge coefficient was invalid for calculating DSR in arid and semi-arid regions. This study shows that DSR is closely related to the strong precipitation events, rather than to the average annual precipitation, as well as the precipitation patterns.