Ecohydrology study in the Bogotà savannah using isotope analysis and numerical mode

M GARCIA JENNIFER; MOLANO CAGIGAS CARLOS; DAPEÑA, CRISTINA; SARANDON RAMIRO

Malaga

Congreso; 46th IAH Congress: Groundwater management and governance; 2020

International Association of Hydrogeologists Spanish Chapter

The aquifers of the Bogota Savannah have been intensively pumped since the last century foragriculture, industry and domestic use, generating effects such as the mechanical collapse of wellsand the descent of the water level of up to 250 m in some areas.The main objective of the study was to apply isotope hydrology to calculate water age and watertravel times in Guadalupe and Quaternary geological formations as a tool for calibration of thehydrogeological model and the impact on the ecology of the landscape in the savannah of Bogota.The calibrated hydrogeological model was used and adjusted with the results of the analyses madewith isotopes (carbon 14, oxygen 18, tritium and deuterium), hydrochemistry, geophysicalinformation and satellite images of the área.The current Carbon-14 results show water age for the subsystem of the Cretaceous aquifer of theGuadalupe formation between 2000 and 23,000 years, and that the foothill area is mostly a rechargearea, as confirmed with tritium. The ages were used to adjust the numerical model, obtaining traveltimes according to the isotopic information. The lower part has a lithology with very lowpermeabilities. Although isotope information is not as abundant, it was possible to have a moreadjusted model, which increases the knowledge of the groundwater flow in the aquifer systems inthe Bogotá Savannah