Long-term groundwater recharge rates across India by in situ measurements
Long-term groundwater recharge rates across India by in situ measurements
复制标题
DOI：
10.5194/hess-23-711-2019
复制
发表时间：
2019-02-07
影响因子：
6.3
通讯作者：
Verma, Shubha
中科院分区：
文献类型：
--
作者：
Bhanja, Soumendra N.;Mukherjee, Abhijit;Verma, Shubha
地下水补给维持地下水排放，包括通过泉水和基流流向地表水的自然排放以及通过抽水井的人为排放。在这里，我们首次使用从印度（330 万平方公里面积）（全球地下水压力最严重的地区）多个地下水位监测点获取的数据来计算长期（1996-2015 年）地下水补给率。对印度 22 个主要河流流域的地下水补给率的空间变化（全流域平均值：17 至 960 mm yr(-1)）进行了估计。印度河-恒河-雅鲁藏布江（IGB）河流域的广阔平原普遍受到相对较高的补给。这主要是由于粗沉积物的出现、降雨量增加以及与集约灌溉相关的地下水抽取，通过增加可用地下水储存和回流来诱导补给。中部和南部大部分研究区域的较低补给率（< 200 mm yr(-1)）出现在克拉通结晶裂隙含水层中。估计的补给率与基于示踪剂（氚）注入测试的现场规模补给率估计（n = 52）进行了比较。结果表明，降水率对印度大部分河流流域的地下水补给没有显着影响，这表明人类对补给率的影响。补给率的空间变异性可以为政策制定者在印度制定更可持续的地下水管理提供关键投入。
Groundwater recharge sustains groundwater discharge, including natural discharge through springs and the base flow to surface water as well as anthropogenic discharge through pumping wells. Here, for the first time, we compute long-term (1996-2015) groundwater recharge rates using data retrieved from several groundwater-level monitoring locations across India (3.3 million km(2) area), the most groundwater-stressed region globally. Spatial variations in groundwater recharge rates (basin-wide mean: 17 to 960 mm yr(-1)) were estimated in the 22 major river basins across India. The extensive plains of the Indus-Ganges-Brahmaputra (IGB) river basins are subjected to prevalence of comparatively higher recharge. This is mainly attributed to occurrence of coarse sediments, higher rainfall, and intensive irrigation-linked groundwater-abstraction inducing recharge by increasing available groundwater storage and return flows. Lower recharge rates (< 200 mm yr(-1)) in most of the central and southern study areas occur in cratonic, crystalline fractured aquifers. Estimated recharge rates have been compared favorably with field-scale recharge estimates (n = 52) based on tracer (tritium) injection tests. Results show that precipitation rates do not significantly influence groundwater recharge in most of the river basins across India, indicating human influence in prevailing recharge rates. The spatial variability in recharge rates could provide critical input for policymakers to develop more sustainable groundwater management in India.