Análise hidrológica para gestão de conflitos em bacias hidrográficas: Estudo de casos do córrego Entre Folhas – Minas Gerais

Abstract

The problems of shortages, conflicts and water stress, year after year, have been plaguing watersheds and becoming increasingly frequent. The assessment of water quantity and quality is an essential factor for good management of water resources. The reasons that led to the choice of this hydrographic basin were: a) the increase in water demand in the region; b) availability of water, decreasing every year, compromising agrosilvopastory activities and public supply; c) water scarcity of the last 30 years; d) imminent risks of conflicts in the basin. The hydrological analysis for conflict management in hydrographic basins: A case study of the Entre Folhas stream – Minas Gerais has as main objective to assist in the management and management of the distribution of water resources, ensuring a fair distribution, without generating conflicts and without overloading the water system to the point of causing water stress in the basin. Carrying out the crossing of data obtained from the methodological procedure, it became evident that the irrational extraction of the volume of water in the watershed in any climatic period is the main cause of water stress and conflicts in the region. With this methodology we reached the following results: the morphometric analysis of the basin regarding the drainage density (Dd) of 1.4 km/km² indicates that the basin has medium impermeability, with a good capacity for underground water storage. It has a Compactness coefficient (Kc) of 1.6, implying a basin not subject to flooding, being confirmed by the form factor (Kf) of 0.32, where, Kf ≤ 0.50 basin not subject to flooding. The Circularity Index (ICC) of 0.32, this value being less than 0.51, it is an elongated basin, thus favoring the flow. Regarding the hydrological behavior, the following morphometric parameters of the basin were considered. Drainage area (Ad) of 89.29 km² with a perimeter of 54 km. As for the slope, the basin has percentages from 0 to 14% in the floodplains and above 55% in need of reforestation. Hypsometric intervals of 272 m at the mouth and > 877 m at the highest point of the basin. The water balance through the methodology of Thornthwaite and Mather (1955) with the classification of Thornthwaite (1948) using the data of precipitation and evapotranspiration of the year 2020, for the calculations of the balance with the Available Water Capacity – CAD of 100 mm, it was found that in 2020 that Potential Evapotranspiration – ETP exceeded Precipitation – P by 64 mm, with an annual water deficit of 576 mm, distributed in the months of February and between May to November, which indicates that irrigation is necessary for this period in agricultural activities and review of grant issuance processes. Similar situation with the water balance from 1961 to 2019, evapotranspiration with 51 mm and water deficit of 288 mm distributed from May to October. Thus, the hydrological analysis meets the need for Regulation of Water Resources, as a proposal of legal instrumentation in a flexible and integrated way, being adaptable to reality and allowing an effective regulation not only of the State, but also of the river basin committees and management bodies involved in the management and management of water resources.