Centre for Environmental and Marine Studies (CESAM), Department of Environment and Planning (DAO), University of Aveiro, 3810-193 Aveiro, Portugal.
Centre for Environmental and Marine Studies (CESAM), Department of Environment and Planning (DAO), University of Aveiro, 3810-193 Aveiro, Portugal; CBMA - Centre of Molecular and Environmental Biology, University of Minho, Braga, Portugal.
Sci Total Environ. 2020 Sep 20;736:139477. doi: 10.1016/j.scitotenv.2020.139477. Epub 2020 May 15.
Future climate for the Mediterranean climatic region is expected to bring an increase in temperatures, decrease in the precipitation quantity and shifts in the seasonal precipitation pattern. Although the impacts of climate change on water resources have been relatively well explored for the Mediterranean climatic region, the specific consequences for reservoirs and, in particular, water availability and irrigation issues have been less studied. The objective of this work is two-fold: (i) to assess the impacts of future climate changes on water resources availability, quality (focusing on phosphorus loads as this is the limiting nutrient for eutrophication) and irrigation needs for two multipurpose reservoirs in southern Portugal; (ii) to suggest climate change adaptation strategies, especially for the agricultural sector. To this end, the SWAT model was first calibrated against existing data on reservoir inflows as well as phosphorus loads. Then, SWAT was run with climate derived EURO-CORDEX models (RCA4/RACMO22E) for four periods (1970-2000, 2010-2040, 2040-2070 and 2070-2100). Water availability was analysed using the Water Exploitation Index (WEI) that was calculated for both reservoirs combining changes of inflows and irrigation requirements. The results indicated that climate change will negatively impact water availability in both reservoirs, especially under RCP8.5. In the case of the Monte Novo reservoir, future domestic water supply could be constrained by water quality problems related with phosphorus loads. For Vigia reservoir, the high water exploitation will lead to water scarcity problems, mainly as this reservoir on present-day conditions is restrictive on irrigation requirements. Adaptation strategies such as the implementation of high end technology (e.g. soil moisture and plant water stress probes, satellite imagery and drones to evaluate water stress - NDVI) as well as the renewal of the irrigation network and adequate crop selection can help attenuating the effects of climate change on the water resources in this region.
未来地中海气候地区的气候预计将带来气温升高、降水量减少以及季节性降水模式转变。尽管气候变化对水资源的影响已经在地中海气候地区得到了相对充分的研究，但对于水库，特别是水资源可用性和灌溉问题的具体影响研究较少。本工作的目的有两个：（i）评估未来气候变化对葡萄牙南部两个多用途水库水资源可用性、质量（重点关注磷负荷，因为这是富营养化的限制营养物）和灌溉需求的影响；（ii）提出适应气候变化的策略，特别是针对农业部门。为此，首先使用现有的水库流入量和磷负荷数据对 SWAT 模型进行校准。然后，使用气候衍生的 EURO-CORDEX 模型（RCA4/RACMO22E）对四个时期（1970-2000 年、2010-2040 年、2040-2070 年和 2070-2100 年）运行 SWAT。使用水资源开发指数（WEI）分析水资源可用性，该指数是通过结合流入量和灌溉需求的变化为两个水库计算的。结果表明，气候变化将对两个水库的水资源可用性产生负面影响，尤其是在 RCP8.5 下。在Monte Novo 水库的情况下，未来的生活用水供应可能会受到与磷负荷有关的水质问题的限制。对于 Vigia 水库，高水资源开发将导致水资源短缺问题，主要是因为在目前的条件下，该水库限制了灌溉需求。适应策略，如实施高科技（例如土壤湿度和植物水分胁迫探头、卫星图像和无人机评估水分胁迫-NDVI）以及更新灌溉网络和适当的作物选择，可以帮助减轻该地区水资源受气候变化的影响。
