URBANIZATION AND SEDIMENT TRANSPORT IN URBAN STREAMS OF CÃCERES, PANTANAL MATO-GROSSENSE

Abstract

This study aims to comparatively analyze the influence of urbanization on sediment inputs in urban streams of Cáceres, Mato Grosso State, Brazil, with emphasis on changes in land use and land cover within the drainage basins and on the hydrological responses observed in the field. To this end, office-based analysis was conducted, along with the collection of bedload and suspended sediment samples at upstream and downstream sections of the Lava Pés, Fontes, Renato, Sangradouro, and Olhos d’Ãgua streams, followed by laboratory analyses (grain-size distribution by sieving and suspended sediment determination by evaporation). Field observations complemented data interpretation. The results indicated a predominance of fine sand (FS) and very fine sand (VFS) in the bed sediments, with 62.24% FS recorded in the Lava Pés stream (Section 3 - downstream) and 68.79% VFS at the headwaters of the same stream. Elevated concentrations of suspended sediments were also recorded at specific reaches, particularly in the Lava Pés stream (Section 3 - downstream), with 31.51 mg L⻹, and at the headwaters of the Renato stream, with 3.18 mg L⻹, whereas the remaining sampling points showed low concentrations, generally below 0.55 mg L⻹. Streams such as Sangradouro and Olhos d’Ãgua exhibited critical stages of environmental degradation, which precluded sedimentological sampling. Overall, the study demonstrates that urbanization in the surroundings of these streams has significantly altered hydrodynamics, sediment transport capacity, and water quality in the urban streams of Cáceres, highlighting the need for urban re-planning combined with the restoration of permanent preservation areas and continuous environmental management to ensure the sustainability of these fluvial systems.