Assessing methods for the estimation of response times of stream discharge: the role of rainfall duration

Title:

Assessing methods for the estimation of response times of stream discharge: the role of rainfall duration

Creator:

Cuevas , Jaime G., Arumi , José L., and Dörner , José

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:b77aed52-a2b9-4982-b539-9af5e7d484b8
uuid:b77aed52-a2b9-4982-b539-9af5e7d484b8
doi:10.2478/johh-2018-0043

Subject:

empirical equations, lagtimes, semiempirical equations, streamflow, and time of concentration

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Lagtimes and times of concentration are frequently determined parameters in hydrological design and greatly aid in understanding natural watershed dynamics. In unmonitored catchments, they are usually calculated using empirical or semiempirical equations developed in other studies, without critically considering where those equations were obtained and what basic assumptions they entailed. In this study, we determined the lagtimes (LT) between the middle point of rainfall events and the discharge peaks in a watershed characterized by volcanic soils and swamp forests in southern Chile. Our results were compared with calculations from 24 equations found in the literature. The mean LT for 100 episodes was 20 hours (ranging between 0.6–58.5 hours). Most formulae that only included physiographic predictors severely underestimated the mean LT, while those including the rainfall intensity or stream velocity showed better agreement with the average value. The duration of the rainfall events related significantly and positively with LTs. Thus, we accounted for varying LTs within the same watershed by including the rainfall duration in the equations that showed the best results, consequently improving our predictions. Izzard and velocity methods are recommended, and we suggest that lagtimes and times of concentration must be locally determined with hyetograph-hydrograph analyses, in addition to explicitly considering precipitation patterns.

Language:

Slovak

Rights:

http://creativecommons.org/publicdomain/mark/1.0/
policy:public

Coverage:

143-153

Source:

Journal of hydrology and hydromechanics | 2019 Volume:67 | Number:2

Harvested from:

CDK

Metadata only:

false