ESTIMATIVA REMOTA DA CAPACIDADE DE ARMAZENAMENTO E DO ASSOREAMENTO DO RESERVATÓRIO DO DESCOBERTO

Código

PAP015

Autores

Tairone Urcino Oliveira, BRUNO COLLISCHONN

Tema

PROCESSOS HIDROSSEDIMENTOLÓGICOS E MORFOLÓGICOS: FLUVIAIS, LACUSTRES E COSTEIROS

Resumo

The urban water supply system of Brasília experienced a severe crisis during the last two years because of the low levels of its main freshwater source, the Descoberto reservoir. The last bathymetric survey was done in 2002, but increasing urbanization and soil use changes in the watershed have led to fears that the reservoir suffered a loss of capacity since then, due to siltation. In this study, we propose a less time-consuming and expensive approach to estimate the capacity of artificial reservoirs, based on the integration ofwater levels with inundated area obtained from satelite imagery. We applied it to the Descoberto reservoir, and we compared the resulting depth-area-volume curve with the existing one, in order to assess siltation and the loss of capacity during the period. We compared this estimation of siltation with a theoretical one, based on classical hydrosedimentological methods. Results from the remote sensing approach show inexpressive loss of capacity in the last 15 years, which is consistent with theoretical estimates and with visual assessments made during the low-level period.