Abstract

A water shortage has been affecting Chile in recent years. Due to the negative effects that water deficit can generate on the environment and the population, an improved understanding of the influence of climatic and anthropogenic factor on water depletion is needed, especially in arid regions such as northern Chile. The main objective of this study is to assess the implications of climatic and anthropogenic variables on the water deficit of the Copiapó River basin, Atacama region, Chile. The study period spans from 2001/02 to 2021/22 seasons. MODIS satellite products (MOD10a2 and MOD16a2) and Landsat images were used for this analysis. Water extraction information obtained from the Chilean National Water Agency (DGA) was also included for this study. The analyzed variables include actual evapotranspiration (ETr), Snow Water Equivalent (SWE), and water use for mining and agriculture. Changes in Snow Water Equivalent (SWE) in the Andes were analyzed as climatic variables, while changes in irrigation and water extraction for mining were used as anthropogenic variables. The amount of water lost by the basin through actual evapotranspiration (ETr) was estimated to quantify changes in water reduction. The results show a significant reduction (p<0.05) of water at a rate of 0.7 Mton/year. Through correlation analysis, an important relationship was found between this reduction and the consumption of the mining sector (-0.52), suggesting that the anthropogenic forcing influences the water deficit more than the climate. Enhanced monitoring of water extraction will contribute to a more accurate identification of its effects on water availability.