Jiménez-Bonilla A, Rodríguez-Rodríguez M, Yanes J L, Gázquez F
Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Seville, Spain.
Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Seville, Spain.
Sci Total Environ. 2023 Dec 20;905:167183. doi: 10.1016/j.scitotenv.2023.167183. Epub 2023 Sep 20.
The hydrological functioning of wetlands in S Spain is poorly understood. We perform a 22-years hydrological modelling of seven playa-lakes located in a semi-arid region of southern Spain, including dry and wet periods. To do that, we applied a hydrological balance model to reconstruct past lake water levels. In addition, we investigated the hydrochemistry of the water, the basin bathymetry, and the geological setting of the watersheds, acquiring new lithology and active structures data. Once the models were constrained, scenarios considering increases on temperature and human management were implemented, and discussed. The water balance is simplified to precipitation (water input) and basin discharge (evapotranspiration), as the lakes are disconnected from groundwater because of the low-permeability substrate. In addition, unlike in previous studies, we add overflows to the modelling. The results of the model agree with actual lake water monitoring data (R > 0.8). We observed that the hydroperiods of some of these lakes vary from permanent lakes to ephemeral, depending strongly on the basin bathymetry. Lakes with steeply margins show longer hydroperiods, whilst it is shorter for low-lying floor playa-lakes. In addition, we observed that steeply lake margins respond to active faults and/or lithological changes. To forecast the effects of climate change on the lake hydroperiods, we applied a 1 °C increase in average temperature in our hydrological modelling. The hydroperiod is significantly reduced for ephemeral playa-lakes, whilst is barely affected in permanent lakes. Moreover, we detected the high sensitivity of ephemeral playa-lakes to the anthropogenic management, including siltation, plant colonization and changes watershed surface.
西班牙南部湿地的水文功能鲜为人知。我们对位于西班牙南部半干旱地区的七个季节性湖泊进行了为期22年的水文模拟，涵盖干旱和湿润时期。为此，我们应用了水文平衡模型来重建过去的湖泊水位。此外，我们研究了湖水的水化学、湖盆测深以及流域的地质背景，获取了新的岩性和活动构造数据。在对模型进行约束后，实施并讨论了考虑温度升高和人类管理的情景。由于低渗透性基底，湖泊与地下水隔绝，因此水平衡简化为降水（水输入）和湖盆排水（蒸发散）。此外，与以往研究不同的是，我们在模拟中加入了溢流。模型结果与实际湖泊水位监测数据相符（R>0.8）。我们观察到，其中一些湖泊的水文周期从永久性湖泊到临时性湖泊各不相同，这在很大程度上取决于湖盆测深。边缘陡峭的湖泊水文周期较长，而地势低洼的季节性湖泊水文周期较短。此外，我们观察到陡峭的湖岸边缘与活动断层和/或岩性变化有关。为了预测气候变化对湖泊水文周期的影响，我们在水文模拟中将平均温度提高了1℃。临时性季节性湖泊的水文周期显著缩短，而永久性湖泊几乎不受影响。此外，我们发现临时性季节性湖泊对人为管理高度敏感，包括淤积、植物定殖和流域地表变化。
