MODELAGEM DA CARGA SEDIMENTAR NO RIO DOS SINOS, APÓS DESASTRES HIDROSSEDIMENTOLÓGICOS EM 2017 - ROLANTE/RS, BRASIL

Código

ENES20200004

Autores

Fernando Mainardi Fan, Ana Flavia Brancalion Costa, Marcelle Gressler

Tema

06 - RISCOS E DESASTRES RELACIONADOS AOS SEDIMENTOS

Resumo

The hydrosedimentological events that occurred in the city of Rolante/RS, in January 2017, resulted from intense precipitations that reached the hillside areas of the region. As a consequence, hundreds of landslides formed debris flow to the basin's channels resulting in significant economic losses. About 350 landslide scars were observed in an area of 230 hectares. However, the effects of this disaster were not only restricted to Rolante. The sediments from the landslides reached Rio dos Sinos causing interruption of supply to at least other ten cities. To characterize the sediment's wave time, we got in touch with the supply systems of the affected cities. The water quality model SIAQUA-IPH was used to simulate the event based on the river's estimated discharges. The simulated results for the cities of Taquara, Campo Bom, Sapiranga, Estância Velha, Portão, Novo Hamburgo, São Leopoldo, Esteio, Sapucaia do Sul and Canoas proved to be interesting in a context of lack of data and on a basin scale. The first cities showed a good correlation between the time of observation of the plume and the beginning of the simulated pollutograph; the others registered a greater correlation between the observation time and the peak of the pollutograph. The uncertainties present in the simulation are linked to i) the inaccuracy of the data; ii) the location of the water intake; and iii) the lack of sediment concentration data. Considering a total simulation time of 72 hours, the error in relation to the total simulated time was approximately 4%.