Análise de métodos para dimensionamento de reservatório de detenção em área sujeita a alagamentos através de simulação no HEC-HMS: área de estudo na sub-bacia PD14, Teresina-PI

Abstract

The capital of the state of Piauí, Teresina, can be considered a "Mesopotamia" on Brazilian soil, given its geographical location between the two main water bodies that irrigate the Piauí territory, the Parnaíba and Poti rivers. This scenario, combined with a high rate of urban site impermeabilization, gives the municipality a peculiar hydrological context, marked by significant challenges, especially concerning urban drainage. Thus, the present study aims to evaluate the implementation of a detention reservoir, a structure designed to temporarily store excess water from intense precipitation events. For this purpose, four distinct preliminary reservoir sizing methods were analyzed to determine the methodology that best suits the inherent characteristics of the chosen sub-basin, PD14, located in the eastern zone of the city. The choice of this particular sub-basin was due to its vulnerability to flooding, given its geomorphological aspects. The methods addressed were: the Method of the Former Complementary Law No. 4723 of June 3, 2015, of Teresina-PI, the Tsuchiya Method, the Urbonas and Glidden Method, and finally, the Rational Method. Subsequently, reservoir volumes were obtained by applying each method to a specific area within the PD14 sub-basin. In the end, the applicability and functionality of the methods were compared, and their ability to relate different scenarios and hydrological variables were decisive factors for selecting the ideal method. Consequently, the Urbonas and Glidden Method, by considering a greater number of variables, was chosen as the most suitable despite its limitations.