Quantification of suspended sediments in the watershed of the Paiva Castro Reservoir, Juqueri River, southeastern state of São Paulo

This study presents the results of field surveys regarding flow measurements, water collection and suspended sediment samples, laboratory analyses (grain-size distribution, suspended sediment concentration, and total dissolved solids), and calculations of suspended sediment load in the watershed of the Paiva Castro Reservoir, Mairiporã, SP. The activities were conducted from October 2023 to December 2024, comprising 21 monitoring campaigns. Five sediment monitoring stations were defined along the Juqueri River. Measurements involved flow gauging using an acoustic Doppler device (ADCP RS-5) and collection of suspended sediments using a DH-48 sampler, in addition to laboratory analyses of suspended sediment concentration, particle size, and total dissolved solids. The equal-width increment (EWI) method was used, allowing detailed vertical and cross-sectional sediment distribution data. The results highlight the spatial and temporal variability of suspended sediment concentrations, which is essential for understanding erosion processes and for planning preventive and corrective actions to mitigate reservoir siltation. Keywords: hydrosedimentology, solid discharge, total dissolved solids.