Flash flood warnings using the ensemble precipitation forecasting technique: A case study on forecasting floods in Taiwan caused by typhoons
Journal
Journal of Hydrology
Journal Volume
520
Pages
367-378
Date Issued
2015
Author(s)
Abstract
A flash flood is an event that develops rapidly. Given early warnings with sufficient lead time, flood forecasting can help people prepare disaster prevention measures. To provide this early warning, a statistics-based flood forecasting model was developed to evaluate the flooding potential in urban areas using ensemble quantitative precipitation forecasts (the Taiwan Cooperative Precipitation Ensemble Forecast Experiment, TAPEX). The proposed model uses different sources of information, such as (i) the designed capacity of storm sewer systems, (ii) a flood inundation potential database, and (iii) historical flooding observations, to evaluate the potential for flash flooding situations to occur. Using 24-, 48- and 72-h ahead precipitation forecasts from the TAPEX, the proposed model can assess the flooding potential with two levels of risk and at the township scale with a 3-day lead time. The proposed model is applied to Pingtung County, which includes 33 townships and is located in southern Taiwan. A dataset of typhoon storms from 2010 to 2014 was used to evaluate the model performance. The accuracy and threat score for testing events are 0.68 and 0.30, respectively, with a lead time of 24. h. The accuracy and threat score for training events are 0.82 and 0.31, respectively, with a lead time of 24. h. The model performance decreases when the lead time is extended. However, the model demonstrates its potential as a valuable reference to improve emergency responses to alleviate the loss of lives and property due to flooding. © 2014 Elsevier B.V.
Other Subjects
Disaster prevention; Flood control; Floods; Hurricanes; Risk assessment; Storm sewers; Storms; Early Warning System; Flash flood; Flood forecasting models; Precipitation forecast; Precipitation forecasting; Quantitative precipitation forecast; Sources of informations; Storm sewer systems; Weather forecasting; data set; ensemble forecasting; flash flood; flood forecasting; hazard assessment; numerical model; precipitation (climatology); typhoon; urban area; Taiwan
Type
journal article