Estimating time of concentration by DMCA method; [DMCA 기법을 이용한 도달시간 추정]

초록

The time of concentration (Tc) is a critical parameter in the planning and design of hydraulic structures. Conventional methods such as physical methods with isochrones and regression based on topographic data, usually produced results with significant uncertainty. Therefore, The objective of this study is to introduce the newly developed method and to test its applicability to a domestic watershed. This study introduced the Detrending Moving-average Cross-correlation Analysis (DMCA) method, which can estimate Tc directly from observed rainfall and runoff data. Application with six conventional formulas to the Soyangang Dam basin yielded Tc values ranging from 10.20 hr to 46.24 hr, highlighting substantial uncertainty. DMCA method showed the reduced uncertainty as data length increased, with Tc estimated at 13.00 hr when the full data set was used. This study has certain limitations, including the use of a single watershed and rainfall station, as well as subjective screening of rainfall and runoff data. Future research should extend the analysis to a larger number of gauged basins to identify watershed-specific characteristics of existing Tc formulas and to propose appropriate Tc ranges. Also the DMCA method may provide an alternative approach for Tc estimation in ungauged basins. © 2025 Korea Water Resources Association.

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