The time of concentration application in studies around the world: a review

Abstract

The time of concentration (Tc) is the main hydrological parameter used to characterize the response of a given Hydrological Response Unit (HRU) to a precipitation event. Because of its importance, the determining Tc is an integral step in several studies involving runoff. Thus, this work presents an unprecedented review of the application of Tc in different lines of research involving water resources around the world. In this article, 1252 publications were listed, obtained from seven different databases, published by 2020, that presented the expressions "time of concentration," "runoff," and "watershed." The articles and conference papers obtained in this research were classified into 12 topics. The number of publications per topic and per country was measured and a cluster analysis was developed to verify the similarity of the distribution of topics per country. In addition, 125 equations applied in related publications for the estimation of Tc are also listed.

Characteristics and Estimation of the Time of Concentration for Small Forested Catchments in Steep Mountainous Terrain

“…As mentioned above, there are modified empirical equations for estimating T C , and the equations primarily developed for specific spatial characteristics include steep slopes and short stream channel lengths within a relatively small catchment (e.g., [41]). These results suggest that the compiled T C estimation equations can be used for consultation with researchers and designers who need to estimate the T C for a region with specific characteristics, allowing for the verification of potential areas for further research (e.g., [48,93,94]). Therefore, the above results indicate that the estimated T C was appropriate for each catchment variable.…”