Análise Qualitativa do Assoreamento do Reservatório de Promissão (SP)

Abstract

Siltation of reservoirs formed by dam building is inevitable, and the consequences of this process are lessened by knowledge of the process dynamics and the implementation of corrective and preventive control measures. In this research the siltation of Promissao Reservoir (located in Middle Tiete watershed) was investigated. Analysis of the siltation process was based on changes in the reservoir bottom level by comparing the original lake topography during the reservoir filling period in 1975, with the topobathymetry obtained in 2005. The results showed the degree of siltation of the compartments studied, as well as the sediment location, within or outside the active volume. The main body of the reservoir was little affected by siltation and among the most important reservoir tributaries, the Porcos River and Batalha River were the most affected. Other less important tributaries were fully silted up or had a high degree of siltation, with the largest share of sediment deposited in the active volume compartment. The qualitative analysis of silting data was effective to determine the stage of siltation in the tributaries and in the main body of Promissao Reservoir