Analysis of the physicochemical variation in water sources with different temporality of post-exploitation surface mining in Jigualito, Condoto, Chocó, Colombia

Abstract

We made an analysis of the variation of the physicochemical characteristics of the water in water sources affected by open pit mining in different time of abandonment in Jigualito, Condoto, Chocó, for which four sampling scenarios were selected, the first one of reference without mining history and the remaining three with current mining, 10 and 30 years of cessation of activity. In each one, hydraulic variables were determined and in situ measurements of 10 physicochemical variables were performed in the water. Sampling was done between May and October 2015. It was determined that the concentration of suspended material, temperature and nutrients are the physicochemical characteristics that determine the spatiotemporal dynamics of the water scenarios disturbed by mining and explain the 83.5 % of the variability of the data obtained. Statistical analyzes show that, due to the greater temporality of the cessation of activity, there is a reduction in the levels of contamination of the resource, since the concentrations of these variables decrease, indicating that the time benefits the reestablishment of the physicochemical conditions of the water bodies, there are environmental conditions that are difficult to recover due to changes in hydraulic characteristics, re-forming of the channel, changes in the structure of riparian vegetation and connectivity lost during the mining process that the nutrient dynamics in the system will be modified even in scenarios of 30 years of mining abandonment.