The Teles Pires River basin is experiencing significant water challenges due to recent urban growth, expansion of irrigated agriculture, and the rise of hydroelectric power plants in Brazil’s forest and savanna regions, impacting water availability and sediment production. This study evaluated and estimated the production of suspended sediment (Q_ss) and total sediment (Q_st) in rivers and streams of the Teles Pires River basin, using different sampling methods for suspended-solid discharge: vertical sampling (reference), composite sampling (section), sampling along the standard vertical, and sampling along three verticals, collected using the equal-width increment method. The Q_ss and Q_st values varied from 0.31 to 39.35 metric tons (t) per day (d⁻¹) and from 0.32 to 43.70 t d⁻¹, respectively. The average percentages of the entrained solid discharge varied from 3 to 5%, between the dry and rainy seasons, and across all hydrological sections. The different sampling methods of Q_ss resulted in similar Q_st in each of the monitoring sections. The statistical performance of the simple linear regression model was satisfactory with Willmott index of agreement greater than 0.8234 and 0.9455 for estimates of Q_ss and Q_st, respectively. The dynamics of sediment production and transport was influenced by land use and cover, drainage area, and the hydrological seasonality of the region. The different sampling methods of Q_ss are compatible with obtaining suspended and total solid discharge; however, the standard vertical sampling is the most simplified and can be applied in a hydrological section with uniform hydraulic conditions.

Modelagem Hidrológica Combinado à Mudança Climática, Uso e Ocupação do Solo

Both the excess and alteration of bed sediments in river systems can cause socioeconomic and environmental damage; thus, the quantification of bedload transport is an important tool to assess the health of rivers and help in decision-making imposed by the agencies responsible for water resource management. This work aims to evaluate the efficiency of pressure-difference samplers (Helley–Smith) qualitatively and quantitatively when used in environments with sandy characteristics. The experiments were carried out in a stream with full transparency and two pressure-difference samplers with nozzle dimensions of 7.20 × 7.20 cm and 8.89 × 7.50 cm. The Particle Image Velocimetry technique was used to analyze the sampler efficiency simultaneously with an Acoustic Doppler Current Profiler. Qualitative results showed that the way the equipment is allocated at the bottom of the river can generate overestimated or underestimated sediment transport measurements. Additionally, evaluating it quantitatively, we see that the collection efficiency of the equipment varied between 15.45% and 534.78% when compared to the results obtained by the Particle Image Velocimetry technique.

Modelagem Hidrológica de larga escala com abordagem inercial/ Large scale Hydrological modeling with inerial approach