Forschungszentrum Jülich GmbH, Institut für Bio- und Geowissenschaften, Agrosphäre (IBG-3), D-52425 Jülich, Germany; Christian-Albrechts-Universität zu Kiel, Geographisches Institut, D-24118 Kiel, Germany.
Forschungszentrum Jülich GmbH, Institut für Bio- und Geowissenschaften, Agrosphäre (IBG-3), D-52425 Jülich, Germany.
Sci Total Environ. 2016 Feb 1;543(Pt B):937-51. doi: 10.1016/j.scitotenv.2015.04.122. Epub 2015 May 15.
This study examines the impact of changing climatic conditions on groundwater recharge in the Riu Mannu catchment in southern Sardinia. Based on an ensemble of four downscaled and bias corrected combinations of Global and Regional Climate Models (GCM-RCMs), the deterministic distributed water balance model mGROWA was used to simulate long-term mean annual groundwater recharge in the catchment for four 30-year periods between 1981 and 2100. The four employed GCM-RCM combinations project an adverse climatic development for the study area: by the period 2071-2100, annual rainfall will decrease considerably, while grass reference evapotranspiration will rise. Accordingly, ensemble results for our base scenario showed a climate-induced decrease in the median of annual groundwater recharge in areas covered by Macchia from 42-48mm/a to 25-35mm/a between the periods 1981-2010 and 2071-2100, corresponding to a reduction of 17-43%. To take into account the influence of additional plant available water storage in weathered bedrock on groundwater recharge generation, the model was extended by a regolith zone for regions covered by Mediterranean Macchia. In a set of model runs ("scenarios"), parameter values controlling the water storage capacity of this zone were increased step-wise and evaluated by comparison to the base scenario to analyze the sensitivity of the model outcome to these changes. The implementation of a regolith zone had a considerable impact on groundwater recharge and resulted in a decrease of the median in annual groundwater recharge: by 2071-2100, the 35% scenario (available water content in the regolith of 3.9 to 5.7vol.%) showed a reduction of 67-82% as compared to the period 1981-2010 in the base scenario. In addition, we also examined the influence of changes in the crop coefficients (Kc) as well as different soil texture distributions on simulated groundwater recharge.
本研究考察了气候变化对撒丁岛南部里乌曼努流域地下水补给的影响。基于四个经过降尺度和偏差校正的全球和区域气候模型（GCM-RCM）组合，使用确定性分布式水量平衡模型 mGROWA 模拟了该流域四个 30 年时期（1981 年至 2100 年）的多年平均地下水补给。四个所采用的 GCM-RCM 组合预测研究区域的气候将呈不利发展：到 2071-2100 年期间，年降雨量将大幅减少，而草地参考蒸散量将上升。因此，我们基础情景的集合结果显示，气候导致马基娅覆盖地区的年地下水补给中位数在 1981-2010 年至 2071-2100 年期间从 42-48mm/a 减少到 25-35mm/a，减少了 17-43%。为了考虑风化基岩中可利用植物水分储存对地下水补给产生的影响，模型在覆盖地中海马基娅的区域扩展了一个风化层区域。在一组模型运行（“情景”）中，逐步增加控制该区域储水能力的参数值，并通过与基础情景进行比较来评估，以分析模型结果对这些变化的敏感性。风化层区域的实施对地下水补给有很大影响，导致多年平均地下水补给中位数减少：到 2071-2100 年，35%情景（风化层中的可用水量为 3.9 至 5.7vol.%）与基础情景相比，减少了 67-82%。此外，我们还研究了作物系数（Kc）变化以及不同土壤质地分布对模拟地下水补给的影响。
