| Title: | Simulating flash floods at hourly time-step using the SWAT model |
| Authors: | Boithias, L., S. Sauvage, A. Lenica, H. Roux, K.C. Abbaspour, K. Larnier, D. Dartus and J.M. Sánchez-Pérez |
| Year: | 2017 |
| Journal: | Water |
| Volume (Issue): | 9(12) |
| Pages: | |
| Article ID: | 929 |
| DOI: | 10.3390/w9120929 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | Green-Ampt and sub-daily processes |
| Secondary Application Category: | flood impacts or conveyances |
| Watershed Description: | 1400 km^2 Têt River, located along the Mediterranean Sea coast in southern France. Altitudes range from 2800 m a.s.l. in the Pyrenees Mountains down to sea level. Two outlets: Marquixanes (810 km²) and Catllar (90 km²). |
| Calibration Summary: | Minimum Drainage Area Time-Step R2 NS PBIAS
Marquixanes
15 km2 Daily Calibration 0.65 0.65 −4.7
15 km2 Hourly Calibration 0.56 0.54 13.4
1 km2 Hourly Calibration 0.10 −0.28 18.7
Catllar
15 km2 Hourly Calibration 0.48 0.46 −34.3 |
| Validation Summary: | Minimum Drainage Area Time-Step R2 NS PBIAS
Marquixanes
15 km2 Daily Validation 0.66 0.64 13.5
15 km2 Hourly Validation 0.49 0.45 7.6
1 km2 Hourly Validation 0.28 0.21 0.6
Catllar
15 km2 Hourly Validation 0.35 0.32 17.2 |
| General Comments: | |
| Abstract: | Flash floods are natural phenomena with environmental, social and economic impacts. To date, few numerical models are able to simulate hydrological processes at catchment scale at a reasonable time scale to describe flash events with accurate details. Considering a ~810 km2 Mediterranean river coastal basin (southwestern France) as a study case, the objective of the present study was to assess the ability of the sub-daily module of the lumped Soil and Water Assessment Tool (SWAT) model to simulate discharge (1) time-continuously, by testing two sub-basin delineation schemes, two catchment sizes, and two output time-steps; and (2) at flood time-scale, by comparing the performances of SWAT to the performances of the event-based fully distributed MARINE model when simulating flash flood events. We showed that there was no benefit of decreasing the size of the minimum drainage area (e.g., from ~15 km2 down to ~1 km2) when delineating sub-basins in SWAT. We also showed that both the MARINE and SWAT models were equally able to reproduce peak discharge, flood timing and volume, and that they were both limited by rainfall and soil data. Hence, the SWAT model appears to be a reliable modelling tool to predict discharge over long periods of time in large flash-flood-prone basins. |
| Language: | English |
| Keywords: | flash storm; flood event; sub-daily simulation; peak discharge; runoff; MARINE model; Mediterranean watershed |