摘要：This article presents the simulation of precipitation parameters and of geometrical and morphological characteristics of hypothetical basins to carry out a sensitivity analysis and find out how much, in what proportion and which factors generate the highest peak flows in the drainage basins. The sensitivity analysis supports management strategies in major drainage systems urban planning and guides professionals of different areas that act in the management of urban stormwaters. The software Civil 3D was used to generate the digital terrain model (DTM) in order to reproduce the hypothetical basins and to create the fictitious scenarios for 3 drainage basins. Together, they generated 9 modeling events to be analyzed. The hydraulic and hydrologic modeling was carried out through the preprocessing and characterization of the drainage basins using the software Hec-Geo-HMS (Geospatial Hydrologic Modeling). Then, the generated data were exported to the HEC-HMS (Hydrologic Modeling System) model. Based on the variation of form, precipitation, land use and occupation, it was possible to analyze the different results in relation to peak flow. Maximum flow occurs in "vertical" scenarios, while lower flows occurs in basins of a more "horizontal" shape. For a return period (TR) of 100 years, regarding the time taken to reach peak flow in basins of the same shape, in rural areas peak flow is anticipated between 9 and 25 minutes, while in more urbanized basins peak flow occurs virtually at the same time, regardless of an increase in precipitation. It can also be concluded that, if impermeability is increased in basins with the same physiographic characteristics, the beginning of surface runoff is anticipated from 2:33 to 3:02 hours. While the time taken to reach peak flow when the basins are not rural anymore and become urbanized varies from two hours and a half to one hour.
关键词：HEC-HMS;Geometric and morphological characteristics
