Identifying aquifer recharge areas based on secondary information in the Chinchiná river basin and reviewing its current status

Identifying potential aquifer recharge zones is essential for sustainable groundwater management, particularly in regions affected by land-use changes and climate variability. This study aimed to map and assess aquifer recharge areas in the Chinchiná River Basin using secondary data and GIS-based spatial analysis based on the soil balance method proposed by Schosinsky. Key variables included monthly precipitation, vegetation cover, slope, soil texture, and evapotranspiration. Infiltration coefficients ranged from 0.06 in steep areas to 0.30 in flat zones. Three main recharge zones were identified: the southeastern Rioclaro River sub-basin (200–300 mm/year), the northeastern Guacaica River sub-basin (100–200 mm/year), and the flatlands near the Cauca River mouth (300–400 mm/year). Vegetation cover significantly influenced infiltration rates, with dense forest showing higher retention capacity than agricultural or urban areas. However, unprotected zones such as the Guacaica and Cauca rivers are under increasing threat from deforestation and unplanned urban expansion. These findings highlight the importance of integrating hydrogeological assessments into regional land-use planning and align with national policies such as Colombia’s National Water Policy and the United Nations Sustainable Development Goal 6. The methodology provides a replicable framework for identifying recharge areas in similar tropical Andean basins where data availability is limited. • The study identified three primary aquifer recharge zones in the Chinchiná River Basin: Southeast sector (Rioclaro River sub-basin): Partially protected within Los Nevados National Park, with recharge rates of 200–300 mm/year; Northeast sector (Guacaica River sub-basin): Unprotected, with recharge rates of 100–200 mm/year; and, Flat areas near the Cauca River mouth: Unprotected, with recharge rates of 300–400 mm/year. • Using the soil water balance method, the study integrated critical variables such as slope, soil texture, vegetation cover, precipitation, and evapotranspiration to quantify and map recharge potential. This approach revealed spatial variations in recharge capacity, emphasizing the importance of these factors in hydrogeological assessments. • The findings underscore the vulnerability of recharge zones to climate variability and anthropogenic pressures, particularly in unprotected areas. Rising temperatures, altered rainfall patterns, and land-use changes (e.g., urbanization, deforestation) threaten the sustainability of groundwater resources, highlighting the need for tailored conservation strategies. • The study emphasizes the urgent need to protect critical recharge zones outside Los Nevados National Park, particularly in the Guacaica River sub-basin and near the Cauca River. It recommends sustainable land-use practices (e.g., reforestation, agroforestry), integrating hydrogeological assessments into regional planning, and addressing structural limitations (e.g., fault zones, rock fracturing) through field investigations and isotopic tracer studies.