"Dr. Eduardo Jorge Usunoff" Large Plains Hydrology Institute, IHLLA, República de Italia 780 C.C. Azul, Buenos Aires, Argentina; National Scientific and Technical Research Council of Argentina, CONICET, Av. Rivadavia 1917, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina.
Dept. Ingeniería Civil y Ambiental, Universidad Politécnica de Cataluña, UPC, Jordi Girona, 1-3, 08034 Barcelona, Spain.
Sci Total Environ. 2020 Jun 20;722:137886. doi: 10.1016/j.scitotenv.2020.137886. Epub 2020 Mar 13.
The analysis of the impact of climate change on water resources in plains requires integral simulation tools that quantify topographic complexity and the strong interaction of groundwater and surface water components (GW-SW). The objective of this study is to implement a coupled hydrological-hydrogeological model under climate change scenarios in order to quantify the spatio-temporal dynamics of water balance and GW-SW interactions for the upper creek basin of Del Azul, which is located in the center of the province of Buenos Aires. The simulation was carried out for a baseline scenario calibrated and validated for the period 2003-2015 and contrasted with two scenarios of the regional climate model CCSM4, RCP (4.5 and 8.5) simulated for the period 2020-2050. First, the annual and monthly anomalies of precipitation, temperature, surface runoff, evapotranspiration, soil moisture, recharge, flow, as well as the discharge, head level and reserves of groundwater are studied. Then the spatio-temporal anomalies of the GW-SW interaction were analyzed and finally wet and dry periods by means of the standardized precipitation index and the annual water balance were studied. Simulation results show that climate change will significantly alter the spatio-temporal patterns of the GW-SW interaction as well as the water balance. These showed monthly, seasonal and annual variations. They show an increase in most of the components of the water balance towards the middle of the 21st century, except soil moisture. Regarding GW-SW interactions, the average annual discharge of the aquifer to the stream is expected to increase by 5% with RCP 4.5 while it will increase 24% with RCP 8.5. The recharge from the stream to the aquifer is expected to increase by 12% with RCP 4.5 while a decrease by 5% with RCP 8.5. Concerning the SPI related to the water balance for the period 2020-2050, alternations of both the time and the length of dry and wet periods are expected for the two scenarios, with RCP 4.5 low frequency of wet episodes, but with a greater severity and permanence in time in contrast to RCP 8.5 that presents less frequency in dry periods, but with high permanence and severity. Climate change could alter groundwater mainly through changes in the recharge, leading to modify groundwater levels and this will cause GW-SW flow to be reversed in some sectors of the stream by increasing or decreasing groundwater discharge into the stream.
分析气候变化对平原水资源的影响需要综合模拟工具，以量化地形复杂性和地下水与地表水成分（GW-SW）的强烈相互作用。本研究的目的是在气候变化情景下实施耦合水文地质模型，以量化位于布宜诺斯艾利斯省中心的德尔阿祖尔上游流域的水量平衡和 GW-SW 相互作用的时空动态。模拟是针对 2003-2015 年期间经过校准和验证的基线情景进行的，并与 CCSM4 区域气候模型模拟的两个 RCP（4.5 和 8.5）情景进行了对比，该情景模拟的时间范围为 2020-2050 年。首先，研究了降水、温度、地表径流量、蒸散量、土壤湿度、补给量、流量以及地下水排泄量、水头和储量的年际和月际异常。然后分析了 GW-SW 相互作用的时空异常，最后通过标准化降水指数和年水量平衡研究了干湿期。模拟结果表明，气候变化将显著改变 GW-SW 相互作用以及水量平衡的时空格局。这些变化表现为月、季和年际变化。除土壤湿度外，21 世纪中叶大部分水量平衡组成部分都呈增加趋势。关于 GW-SW 相互作用，预计 RCP 4.5 下含水层向溪流的平均年排放量将增加 5%，而 RCP 8.5 下则增加 24%。预计 RCP 4.5 下从溪流到含水层的补给量将增加 12%，而 RCP 8.5 下则减少 5%。关于与 2020-2050 年期间水量平衡相关的 SPI，两个情景下预计都会出现干湿期时间和长度的交替，RCP 4.5 下湿期出现的频率较低，但在时间上持续时间较长且严重程度较高，而 RCP 8.5 下则相反，其旱期出现的频率较低，但持续时间和严重程度较高。气候变化可能主要通过改变补给来改变地下水，从而导致地下水位发生变化，并导致一些溪流流域的 GW-SW 流发生反转，增加或减少地下水向溪流的排放量。
