Traditional aquifer recharge practices in Spanish mountains. Insights from semi-arid Sierra Nevada.

Abstract ID: 3.13365 | Not reviewed | Requested as: Talk | TBA | TBA

Thomas Zakaluk (1,2)
Jorge, Jódar (3); Sergio, Martos-Rosillo (1)

(1) Geological and Mining Institute of Spain, IGME-CSIC, Urb. Alcázar del Genil 4, 1ºC, 18006, Granada, Spain
(2) Doctoral School in Science, Technology and Engineering (EDCTI), , University of Granada, Granada 18071, Spain
(3) Geological and Mining Institute of Spain, IGME-CSIC, Av. Montañana 1005, 50059, Zaragoza, Spain

Categories: Agriculture
Keywords: nature-based solution, managed aquifer recharge, careo channel, Anthropocene

Categories: Agriculture
Keywords: nature-based solution, managed aquifer recharge, careo channel, Anthropocene

Abstract

Human interference may have a noticeable impact on the hydrological behavior of small watersheds in high mountains. This is especially true in semi-arid climates where water resources are scarce, but agriculture and pastoralism are of utmost importance to the local livelihoods.

Traditional irrigation communities of Spanish mountain areas have a long tradition in using artificial aquifer recharge as a means of enhancing spring flow and river base flow during the dry summer months. The simple technique, also known as water sowing and harvesting (WS&H), consists in deviating surface water from rivers and gullies with unlined channels during high flow periods to facilitate its infiltration into sloping aquifers either directly through permeable materials or indirectly through irrigating pastureland.

The objective of this work is to give examples from different WS&H practices in Spain, highlighting the importance such nature-based solutions may have, not only socio-economically but also in the way it influences the natural environment. We will present a detailed case study from Sierra Nevada, in which we calculate the water balance of a small watershed based on continuous streamflow monitoring data obtained between 2021 and 2023.

The Mecina watershed (48 km2, 883-2768 m ASL) is characterized by steep slopes and covered almost completely by weathered schists which form thin aquifers (< 50 m). An extensive network of recharge channels, known as acequias de careo, are in use since medieval times to enhance water availability in low-flow periods.

Our results confirm local knowledge on the impacts of careo aquifer recharge. In the water years 2022 and 2023 artificial recharge may have contributed up to 83% and 21% to the total aquifer recharge, respectively. The specific case study not only highlights how human interfere in mountain hydrology by regulating inter-annual river flow variability, but it also calls for the need of field research focused on groundwater-surface water interactions in similar settings.