Estimation of the time of concentration from morphometric and hydrological monitoring parameters in São Paulo state watersheds

Morphometric analyzes support an understanding of the physical characteristics hydrographic basins and are commonly used to estimate hydrological variables. This work aims compare geomorphological time concentration (Tc) in two watersheds: upper part Jundiaí river (139.3 km2) Piraí (209 belonging basin, state São Paulo. To calculate Tc, empirical equations monitored data were applied. Applying US Army Corps Engineers, Ven te Chow, Kirpich Tc formulas, watershed had highest with a mean value 6.29 h maximum difference between three formulas approximately 27%. The for was 5.18 h, 25% variation minimum calculated values. method collected 2018 2021 from Paulo State Flood Alert System (SAISP) fluviometric pluviometric stations, values 6.83 23.33 respectively, 14.4 h. We observed higher watershed, which has larger drainage area, varying 17 49 36.7 Note that average almost 2.5 times than despite equal slope length thalweg, equations. These based on morphometric parameters underestimated compared method, presenting 82% 64% error, watershed.