Use of Weather Radar Data in a SCS-CN Hydrological Model to Estimate Surface Runoff

Abstract

The aim of the present work was to evaluate the feasibility of using rain based on meteorological radar data from the Institute of Meteorological Research of Bauru (IPMet / UNESP) in the implementation of the simplified distributed hydrological model Soil Conservation Service - Curve Number (SCS) - CN), an end of analysis or runoff of events in the Jacaré-Guaçu River watershed, located in the central-eastern region of the São Paulo State. In this work, how to display rain from IPMet weather radar data was calibrated with data from 18 rainfall stations, however, a study area has only one fluviometric station in operation, located outside the basin. Two events that took place in January and February 2013 were selected, according to the spread runoff extracted from the application of a digital runoff selection filter. The results were satisfactory about the propagation of runoff generated by the hydrological model SCS-CN. However, it should be noted that some factors of uncertainty were taken into account in the process of implementing the hydrological model. One of these factors is the lack of calibration of the parameters of the SCS-CN model, such as the tabulated values ​​of the CN, which may produce some spurious data of the effective rain and, consequently, this may have interfered with the values ​​of propagation of the runoff.