Morphometry, Water Availability and Sediment Transport in the River Renato Watershed, Southern Amazon

The reduction in surface water availability in the Brazilian Amazon biome is associated with anthropic activities and climate change, facts that have driven hydrological monitoring studies. Such studies seek to understand the hydrological responses to changes in land use and land cover, aiming at the proper management of water resources in Amazonian river basins. Thus, the objective of the present study was to determine the physiographic characteristics and establish liquid and solid rating curves of the Renato river sub-basin, a tributary of the Teles Pires river, under conditions of restricted data. Measurements of quota, liquid flow (QL) and solid flows in suspension (Qss) and drag (Qsa) took place monthly between February 2019 and November 2022, composing 28 and 16 (fluviometric station 1) and 21 and 16 (station fluviometric 2) measurements of QL, Qss and Qsa, respectively. Physiographic characteristics were determined using the QGIS 3.16.11 software. The Renato River sub-basin had a regular drainage density = 0.505 km km-2, an elongated shape and low probability of flooding (Kf = 0.19; Kc = 2.17 and Ic = 0.21) and the relief varied from flat to strongly undulating (0 to 30%). Regardless of the hydrological section, the statistical performance of the regression models for suspended and total solid flows (Qst) could have been better. It is concluded that the Renato River watershed is little susceptible to extreme flood events due to its elongated shape and regular drainage density. The evaluated regression models adjusted satisfactorily for QL and unsatisfactorily for Qss and Qst. Therefore, there is still a need to continue studies with hydrosedimentological monitoring to build rating curves that accurately estimate the liquid and solid flows.