Name: FERNANDA CALIMAN PASSAMANI
Publication date: 01/09/2016
Advisor:
Name |
Role |
|---|---|
| DANIEL RIGO | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| DANIEL RIGO | Advisor * |
Summary: Coastal cities have, in general, many problems related to rainwater drainage. In addition to the high soil sealing due to urbanization, these regions present the land quotas close to the sea level, low steepness and they are influenced by the tide, aspects that intensify the cases of flooding. This study aimed to evaluate the macrodrainage of a coastal urban basin and evaluate proposals of some control measures to minimize the impacts of flooding. It was chosen as a case study the catchment of Canal da Canal, located in Vila Velha, Espirito Santo state. The softwares used in hydrologic and hydraulic modeling were, respectively, HEC-HMS and HEC-RAS. In the current situation of the basin, it was observed that the backwater caused by the runoff from the sub-basins result in high water levels in the channels for a long time due to the low flow velocity, causing flooding in several inhabited areas of the basin. Three alternative scenarios were evaluated, which was considered the improvement of the channels geometry, macrodrainage deviation of some sub-basins and transposition of rainwater through pumping. Considering the rainfall with a return period of 50 years, it was found that the alternative scenarios significantly attenuated the floods. Flood spots generated for the current scenario only disappeared after 33 hours of the onset of rain and they reached the maximum area equivalent to 27.7% of the total area of the basin. In Scenario 4, WHERE the most efficient control measures were adopted, the flooding ended after 3 hours and the percentage of the basin area affected by the maximum flooding reduced to 8.9%. However, it was observed that the flooding problems have not been solved totally in any scenario. Thus, it is noted that coastal basins occupied could adopt, beyond structural techniques, non-structural control measures that provide a harmonious coexistence of the population with the floods. Such measures can be forecast and warning systems, flood insurance and evacuation plans.
