Diagnóstico ambiental da bacia hidrográfica do Córrego Laranja Doce/MS

Abstract

In view of the changes arising from the current socioeconomic model of Mato Grosso do Sul, such as the intensification of monocultures and, consequently, the possibility of environmental impacts, there is concern about the need to promote an environmental diagnosis, using as a unit of study the basin especially for enabling a better understanding of the interactions between the physical and socioeconomic components and their influences on surface water quality. Therefore, the selection of the Hydrographic Basin (BHCLD) as a unit of study, points out these issues, mainly because it is a basin with direct interference of the urban area of the municipality of Dourados, in addition to the rural area of Douradina, both located in the State of Mato Grosso do Sul. In this context, this research aimed to present a proposal for environmental diagnosis of BHCLD, analyzing its physical and socioeconomic components, as well as exposing the main activities with polluting potential and that are capable of altering the quality of the water of the stream Laranja Doce, according to the Resolution 357/2005 of the National Council of the Environment and the deliberation of the State Council of Environmental Control n ° 36/2012. In this way, seven points of collection of surface water were determined, previously selected because they were areas with polluting potential, thus defining a radius of three kilometers as an analysis site, in order to evaluate the degree of possible changes in the parameters physical and chemical characteristics such as turbidity, dissolved oxygen, pH, total solids, total dissolved solids, carbonic acidity, chlorides, salinity and electrical conductivity. The operationalization of the research was focused on the theoretical-conceptual revision, database organization, field activities, cartographic products elaboration and limnological analysis. According to the State Water Resources Plan (PERH), the water source that does not have a classification is considered as Class II, and before this classification were observed if the results of the selected indicators, responsible for evaluating the water quality of the Orange Stream Twelve, were in agreement with the framework proposed by the Plan, being the less restrictive parameter in the analyzed sections. In contrast to the analyzed, some indicators were not compatible with the Class II framework, and points 2 and 4 presented Class IV characteristics and points 3, 5, 6 and 7 were classified in Class III. In assessing the main activities in the basin, ie, monocultures (soybean, corn and rice) and pasture, as well as, in the springs where the source is in Class III, it was possible to verify that their respective uses corresponded to the framework established, ie the irrigation of tree, cereal and forage crops and animal husbandry (ECSC DELIBERATION No 36/2012), but were not in accordance with the PERH. It can be concluded that the BHCLD can be considered unstable due to the pressures and degradations exerted by the anthropic activities, mainly due to the monocultures, livestock and the urban network, being these activities the main threats to the surface water quality of the Laranja Doce/MS stream These pressures, therefore, make it necessary to promote better environmental and social quality in the BHCLD through projects and programs.