Uso de modelo hidrológico em bacia hidrogáfica urbana para previsão de enchentes. Estudo de caso: Microbacia do Córrego Jataí - Uberlândia/MG

Abstract

The rapid urban growth in many Brazilian cities in the twentieth century occurred without the proper planning and infrastructure. In these cities, floods cause great material and human losses every year. Therefore, the authorities and community must propose and implement flood control measures after detailed studies of the characteristics of the watershed . Thus, hydrological simulations of the stream Jataí watershed located in Uberlândia/MG, was performed using the software ABC - Complex Watershed Analysis, from the University of São Paulo considering the return period of 100 years for the project rain. This watershed has an area of 15.99 km² and was discretized by sub-basins considering the land use and occupation at the current urbanization and critical scenario (fully urbanized and occupied basin). The damping reservoir existent in the study area were considered in the simulations and it was proposed the implementation of a parallel damping reservoir near to the watershed output. The sub-basins 02 and 08 simulated alone at the critical scenario provided the highest maximum flow rates of 193.17 and 162.78 m³/s respectively. Furthermore, the damping reservoirs 02 and 05 showed the largest decreases of input hydrogram peak flow with maximum reductions of 86.3 and 76.6% respectively at the current urbanization scenario. The implementation of the proposed parallel damping reservoir allowed the reduction of peak flows at the basin outlet of 26.8% from 211.65 to 154.87 m³/s in the current scenario and 22.3% reduction from 262.28 to 203, 86 m³/s at the critical urbanization scenario. Based on these results, it is possible to conclude that the damping reservoirs are very important to control runoff and it is necessary and urgent to implement new flood control measures in the Jataí stream watershed to reduce the inconvenience caused by heavy intensity rains.