Flash Flood Warning Assessment Considering Temporal Differences

Hydrological model has been widely used in flash flood warning. The traditional performance criteria of hydrological model focus on the accuracy of prediction, and the errors on both sides of the true value are supposed to be the same when these criteria are used, which often cause false warning and miss warning with the same probability. In the practical prevention and control of flash flooding, the life safety is of primary consideration. Therefore, the casualties caused by miss warning are much more serious than the economic losses caused by false warning. Based on the principle of reducing miss warning, the temporal difference of flood warning, a new performance criterion coupling the time for immediate evacuation, the time for preparing evacuation and the time of disaster occurrence, was proposed. Taking the floods in Guanshanhe river since 1975 as an example, TOPMODEL model, TVGM model and Xin'anjiang model were used to simulate floods based on the temporal difference of flood warning and the traditional criteria, and then the flood warning results were compared with the measured data. It shows that the results of the temporal difference of flood warning and the traditional indices are very different. By using the traditional criteria, TVGM model would be chosen, while TOPMODEL is actually the best model by the criterion of temporal difference of flood warning. As TVGM model causes more miss warnings but has the highest accuracy according to the traditional criteria, which doesn't satisfy the requirements of flash flood warning. Therefore, the effectiveness and reliability of flash flood warning can be improved by using the criterion of the temporal difference of flood warning, which would be more suitable for flash flood warning. Copyright ©2021 Advanced Engineering Sciences. All rights reserved.