Publication:

Evaluación del efecto del cambio climático en la hidrología superficial de la cuenca hidrográfica del lago de Tota, Boyacá

Lake Tota basin is the principal provider of hydric resources for Sugamuxi region, department of Boyacá, Colombia, it supplies drinking water for almost 250.000 people, supplies irrigation districts, industries and several economic activities of the area. The basin is considered as high-altitude mountain, surrounded by Tota – Bijagüal – Mamapacha páramo complex, a strategic ecosystem that provides environmental services like hydric provision and regulation, vulnerable to affectation uncertainty that might have climate change on its ecosystem services. Facing up this problematic, the objective is to determinate the effects of global warming on instrumented subbasins superficial hydrology flow, as availability of hydric resources in the medium term (2020 – 2049). Data series from Institute for Meteorological, Hidrological and Environmental Studies (IDEAM) of the basin and influential zone where acquired, to calibrate and validate the Precipitation – Runoff model on HEC-HMS software based on soil moisture accounting methodology, for Hato Laguna river, Los Pozos creek and Olarte river subbasins. Trough Auto Regresive and Mobile Average Model (ARMA, p, q), probable changes in temperature and precipitation were calculated, to assign the first climate change scenario, denominated ES1; at the same time, scenarios ES2 and ES3 were defined from multiscenario assemble and RCP 8.5 of “Climate Change Scenarios for precipitation and temperature in Colombia 2011 – 2100” inform of IDEAM. In conclusion, hydric offer wouldn’t be negatively affected by global climate change, as precipitation increments around 5% - 30% are expected on analyzed subbasins, increasing flow in range 3% - 37% depending of the scenario. Through Regulation and Retention Hydric Index (IRH) it was observed that Hato Laguna and Olarte subbasin would loss regulation capability, while Los Pozos creek would improve this index. Nevertheless, according to this study results, floods flow will have greater magnitudes impacting negatively agriculture, fish farms, and roads of the region. Increase in temperature also intensivists Evapotranspiration loses, that in long term will reduce dry seasons baseflow of watercourses that reaches Lake Tota.