Initial abstraction ratio and Curve Number estimation using rainfall and runoff data from a tropical watershed

• DOI: 10.1590/2318-0331.241920170199
• Publication Date: 2019-02-05T14:02:27Z
• Authors: Luiz Claudio Galv...; Dulce Buchala Bic...; Paulo Tarso Sanch...
• Keywords: TC401-506; Technology; T; 0207 environmental engineering; Hydrologic modeling; Hydraulic engineering; 02 engineering and technology; 15. Life on land; 6. Clean water; River, lake, and water-supply engineering (General); G; Environmental sciences; CN; 13. Climate action; Geography. Anthropology. Recreation; Ungauged basins; GE1-350; TC1-978; Rainfall-runoff events

ABSTRACT The Curve Number (CN) method is extensively used for predict surface runoff from storm events. However, remain some uncertainties in the method, such as use of an initial abstraction (λ) standard value 0.2 and on choice most suitable CN values. Here, we compute λ values using rainfall data to a rural basin located Midwestern Brazil. We 30 observed rainfall-runoff events with depth greater than 25 mm derive associated five statistical methods. noted ranging 0.005 0.455, median 0.045, suggesting = 0.05 instead 0.2. found S0.2 S0.05 conversion factor 2.865. also negative Nash-Sutcliffe Efficiency (to estimated runoff). Therefore, our findings indicated that was not estimate studied basin. This poor performance suggests mechanisms area are dominated by subsurface stormflow.