Rainfall – CN (Curve Number) relationships in a tropical rainforest microbasin within the Panamá Canal watershed

Abstract

Precipitation (P) Curve-Number (CN) relationships for different base flow ranges, obtained within the upper Chagres River watershed were applied to a 6.5 Ha microbasin located within the Panamá Canal watershed. These relationships estimate CN values from P data employing an equation established by Calvo et al (10). This equation uses k and CN∞ as fitting parameters. Rainfall/Runoff data from the microbasin, collected over a six-month period, were analyzed. These analyses showed that CN values at the microbasin are closer to CN results predicted by the equation corresponding to the lower base-flow range (14-42 m3 /s) at the upper Chagres watershed. These results were explained by considering not the absolute values of the base flow (Qbase), but the value of this parameter relative to the basin area under study.

Keywords

• Panamá Canal watershed
• tropical hydrology
• precipitation
• curve numbe