Evaluación de las condiciones de calidad del agua, para la formulación de estrategias de aprovechamiento y conservación de la microcuenca quebrada la Argentina, Villavicencio – Meta.

Abstract

The main goal of this project was to evaluate the water quality conditions of the La Argentina micro-basin, located in the city of Villavicencio, Meta’s department , to formulate strategies of use and conservation of this one. Initially identificating the current use of the soil inside the studies area with the purpose of analyze the grade of affectation or variation in water quality conditions of the micro-basin. This evaluation through monitoring In Situ (Dissolved Oxygen, Conductivity, Flow, pH, and Water Temperature) Ex Situ monitoring (Biological oxygen demand "BOD5"; Total dissolved solids "SDT"; Hardness; Alkalinity; NO3-N; Total phosphate; Turbidity) and microbiological parameters (total and fecal coliforms), during wet season (October and November of 2017) and dry season (January and February of 2018). The treatment and interpretation of physical, chemical and microbiological data was done through the use of water quality incides “ICA” and pollution indexes" ICO's, by mineralization "ICOMI" and organic matter "ICOMO". It is reported as results; that the water quality conditions of the micro-basin in the wet season, for high and low basins, are acceptable (78,77 – 73,21) and average regular basin (69,06). Also, for dry season, acceptable water quality conditions (76,29 – 75,35 72.98) were found in the three stretches. On the other hand, the mineralization contamination index did not show considerable changes over time, the values obtained show that the microbasin presents high contamination (0,75) by mineralization. On the contrary, ICOMO presented low (0,28) pollution in the three sections, and seasons evaluated. Associated with the above, it was determined that for the two seasons evaluated, the micro-basin represents temperatures between 23.9°C and 28,2°C; in terms of pH, O.D, and conductivity the variations were between 8,44 and 8,8 units; 73,5 and 90% and 544 and 596,5 μS/cm, respectively. The maximum flow was recorded in the wet season (1,10 m3/s) and the minimum in the dry season (0,70 m3/s), with a significant variation in the middle basin (± 0,37 m3/s) due to the contribution of tributaries. Additionally, SDT and total phosphate values were within the range of 390 – 399,65 mg/L, 0,1 and 0,325 mg/L PO4. The parameters that did not show considerable changes over time were BOD5 and NO3-N, with invariable concentrations of 5 mg/L and 3 mg/L NO3 respectively. Acording to the microbiological parameters evaluated, the maximum fecal coliform concentrations were obtained in the dry season, in the middle and upper watershed (31 - 98 NMP/100 mL). Lastly, the hardness parameter recorded the highest concentrations in the two seasons evaluated, with an average of 360,42 mg/L CaCO3, and entering these concentrations significantly in the mineralization contamination index. Finally, proposals were formulated at a conceptual level, focused on the protection and conservation of the microbasin, from different factors (institutional, community, ecotourism, productive use, and care of strategic areas). The above, in order to deliver primary base information to entities or autonomous regional corporations, and support the quality studies of the country's water resources, to provide unknown information regarding water bodies, especially in the Orinoquia Region.