Diagnóstico de processos erosivos visando ações de recuperação e conservação do Rio Coxipó em trechos inseridos no perímetro urbano da capital matogrossense

Abstract

The Coxipó watershed suffered an intense human occupation that brought direct damage to its waters. The negative effects of this interference can be felt in the invasion of permanent preservation areas, in the absence of projects for the collection and treatment of effluents, rainwater drainage networks, and solid waste collection that would serve the entire population of the watershed. Therefore, the project’s aim has as objective to diagnose the erosive processes observed on the banks of the Coxipó River, to characterize the types of risk and to quantify the loss of area due to fluvial erosion, as well as to propose corrective measures for recovery as a way of conserving the watershed. To this end, activities were developed in two steps to understand the erosive dynamics on the slopes along the riverbanks, in the section inserted in the urban area of the Mato Grosso’s Capital. The first step was based on quantifying the soil loss resulting from the fluvial and pluvial erosive processes that have developed along the river. The analysis was carried out through an Unsupervised Classification by ArcGIS Pro software (Student Version), as well as the superimposition of satellite images made available by the Google Earth platform in different periods. The second step was carried out in the field, aiming at the mapping and characterization of three types of risks manifested on the banks of the Coxipó River, classified based on previously defined criteria, besides the proposition of corrective and preventive measures aimed at the containment of the active erosive processes. The result of the first and second steps concludes that the most affected stretches of the river courses are inserted near its mouth, where it presented an erosion annual rate of 39,61 m² and 45,29 m² of silting. Thus, it allowed us to verify intense processes of erosion and siltation resulting from human interference that favored the change in the morphodynamics of the river. To preventing the erosive processes, corrective measures suggest the insertion of gabion structures of the spike type on concave banks, planting of grass, shrub, and tree species using wooden bulkheads on convex and straight banks. To preventive, apply the compliance with the legislation of Areas of Permanent Preservation (APPs) on the banks of the river following the New Forestry Code, as well as supported by the Law of Occupation and Land Use of the Municipality of Cuiabá City through the preparation of a Recovery Plan of Degraded Area (PRAD) as CONAMA Resolution 237/1997.