Abstract Climate change and future abstraction regimes will influence the availability of groundwater resources. To alleviate any potential negative effects on aquifer systems and dependent industrial and human uses, it is important to develop long-term water management plans. This study evaluates the effect of climate change and future increased groundwater demand from a coastal aquifer located in Kwale County in southern Kenya. A previously calibrated numerical groundwater flow model has been used as an assessment tool to study how future climate (precipitation and temperature variation) and groundwater abstraction changes will affect the aquifer system. The groundwater flow model was built to simulate the period 2010 to 2017, and eight future model scenarios were developed that cover six hypothetical future years. Future groundwater abstraction has been based on current allocations and future estimates made by Kenya’s Water Resources Authority. Future rainfall scenarios have been constructed based on a long historical data series (from 1959 to 2017) and the Standard Precipitation Index. The main results show that future abstraction increases due to economic growth exerts a minimum impact compared with expected climate variability. Recharge depends on intense rain events with important implications for both dry periods and for an average rainfall year. A succession of extended dry seasons may affect all water users. However, the groundwater level decline in the local shallow aquifer can reach five meters, with important consequences for local community water supplies. The most significant groundwater decline in drought periods is observed in the area surrounding the pumping wellfields in the deep aquifers, where the effects of drought and significant abstraction are multiplied. However, the effect of increased abstraction on the shallow aquifer system is limited. Despite groundwater level decline observed during prolonged dry periods, a dry period followed by a humid period leads to the relatively swift recovery of the groundwater system.

中文翻译：

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肯尼亚沿海地区地下水易受气候变化和经济增长影响的证据

摘要 气候变化和未来的取水制度将影响地下水资源的可用性。为了减轻对含水层系统和相关工业和人类用途的任何潜在负面影响，制定长期水资源管理计划非常重要。本研究评估了气候变化的影响以及未来肯尼亚南部夸勒县沿海含水层对地下水需求增加的影响。先前校准的数值地下水流模型已被用作评估工具，以研究未来气候（降水和温度变化）和地下水抽取变化将如何影响含水层系统。建立地下水流模型以模拟 2010 年至 2017 年期间，并开发了八个未来模型情景，涵盖六个假设的未来年份。未来的地下水抽取是基于肯尼亚水资源管理局的当前分配和未来估计。未来降雨情景是基于长期历史数据系列（1959 年至 2017 年）和标准降水指数构建的。主要结果表明，与预期的气候变率相比，未来因经济增长而增加的取水量的影响最小。补给取决于强降雨事件，对干旱期和平均降雨年都有重要影响。一连串延长的旱季可能会影响到所有用水者。然而，当地浅层含水层的地下水位下降幅度可达 5 米，对当地社区供水产生重要影响。在深含水层中的抽水井场周围地区观察到干旱期间地下水下降最显着，在那里干旱和显着取水的影响成倍增加。然而，增加取水量对浅层含水层系统的影响是有限的。尽管在长时间的干旱期观察到地下水位下降，但干旱期和湿润期会导致地下水系统相对较快地恢复。