Regional Assessment of Recharge Elevation of Tap Water Sources Using the Isoscape Approach
Regional Assessment of Recharge Elevation of Tap Water Sources Using the Isoscape Approach
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DOI：
10.1659/mrd-journal-d-16-00066.1
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发表时间：
2017-05
影响因子：
1.6
通讯作者：
T. Yamanaka;Yuki Yamada
中科院分区：
文献类型：
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作者：
T. Yamanaka;Yuki Yamada
通过比较上游（山区）和下游（低地）地区的水资源预算，已经量化了山区作为“天然水塔”的重要性，但尚未评估其对自来水供应的重要性。在这里，我们提出了一个isoscape的方法来估计自来水水源（河流，水库，泉水，和威尔斯）的平均补给海拔，并将其应用到日本中部地区作为一个案例研究。估计平均补给高程的误差为90-140米。结果表明，该地区约90%的源的平均补给海拔在海拔1000米或更高。超过一半的土地面积高于海拔，而98%的人口生活在海拔以下。这些发现表明，自来水过度依赖于山区的补给，而不成比例地供应给低地居民。泉水水源地的位置越高，井水水源地地下水流的垂直距离越长，其补给对人口的贡献越大。此外，我们的研究结果表明，较大的城市需要更高的天然水塔，以满足更大的用水需求，辅之以城市间的供水。一些低海拔城市严重依赖其领土以外的山区补充的水。本文提出的方法有助于阐明人们如何依赖山区供水，为山区和水资源的综合管理提供必要的知识。
The importance of mountains as “natural water towers” has been quantified by comparing water budgets in upstream (mountain) and downstream (lowland) areas, but their importance for tap water supplies has not been assessed. Here, we propose an isoscape approach to estimate the mean recharge elevation of tap water sources (rivers, reservoirs, springs, and wells) and apply it to a region in central Japan as a case study. Errors in the estimation of mean recharge elevation were estimated at 90–140 m. Results show that mean recharge elevations for about 90% of sources in the region are at 1000 m above sea level or higher. A little over half of the land area is above that elevation, while 98% of the population lives below it. These findings indicate that tap water disproportionally depends on recharge in mountains and is disproportionately supplied to lowland residents. Higher locations of spring water sources and longer (vertical) distances of groundwater flow for well water sources make the recharge-to-population disproportionality more remarkable. Furthermore, our results suggest that larger cities require higher natural water towers to meet greater water demand, complemented by intermunicipal water suppliers. Some low-elevation municipalities depend heavily on water recharged in mountains well outside their territories. The method proposed here helps clarify how people depend on water supplies from mountains, providing essential knowledge for integrated management of mountains and water resources.