Influência do hietograma sintético na cheia de projeto do Reservatório Macacos no Estado do Ceará

Abstract

This issue analyses the impacts of hyetograph selection in the project runoff generated by the SCS method for the reservoir Macacos basin. It is known that the project runoff is the is the main parameter for the design of water structures and the wrong choice of model can lead to the wrong design. The methods used in the analysis were Alternate Blocks, Advanced Blocks and Lag Blocks. The hyetographs were designed with blocks of 10 minutes duration and 360 minutes of total rain duration. The rain intensities of each block were obtained by five IDF equations from different regions of Brazil, using Tr of 1000 years. Subsequently, with the help of the HEC-HMS program, the inflow to the reservoir was determined by means of the SCS method, adopting a CN coefficient of 80 and the flood propagation was simulated in the reservoir to obtain effluent hydrographs considering the characteristics of the spillway. The IDF obtained similar hyetographs, however with different precipitation heights. After the computational simulation, it was verified that the delayed blocks hyetograph is the one that generates a higher project flow rate. It is recommended to apply this methodology for different values of CN and Tr.