Effects of temporal resolution of input precipitation on the performance of hydrological forecasting

Abstract

Abstract. Flood prediction systems rely on good quality precipitation input data and forecasts to drive hydrological models. Most precipitation data comes from daily stations with a good spatial coverage. However, some flood events occur on sub-daily time scales and flood prediction systems could benefit from using models calibrated on the same time scale. This study compares precipitation data aggregated from hourly stations (HP) and data disaggregated from daily stations (DP) with 6-hourly forecasts from ECMWF over the time period 1 October 2006-31 December 2009. The HP and DP data sets were then used to calibrate two hydrological models, LISFLOOD-RR and HBV, and the latter was used in a flood case study. The HP scored better than the DP when evaluated against the forecast for lead times up to 4 days. However, this was not translated in the same way to the hydrological modelling, where the models gave similar scores for simulated runoff with the two datasets. The flood forecasting study showed that both datasets gave similar hit rates whereas the HP data set gave much smaller false alarm rates (FAR). This indicates that using sub-daily precipitation in the calibration and initiation of hydrological models can improve flood forecasting.

Evaluation of ECMWF medium‐range ensemble forecasts of precipitation for river basins

“…This dataset is especially valuable in the assessment of EPS at sub‐daily scales, as the sub‐daily precipitation can be important in hydrological applications (e.g. Wetterhall et al , 2011; Parkes et al , 2013).…”

Modeling flash floods in southern France for road management purposes

“…Delrieu et al (2013) explored such a data merging method in order to improve radar QPE in the French Mediterranean. The high time frequency of radar data is also a determining factor (Michaud and Sorooshian, 1994;Bouilloud et al, 2010or Wetterhall et al, 2011. Results are sensitive to the radar time-step (Atencia et al, 2011;Anquetin et al, 2010;Bastola and Misra, 2013).…”

Conditioning model output statistics of regional climate model precipitation on circulation patterns

“…Flow levels are generally high in autumn and winter and low in summer. The area is prone to flooding and has recently been a study area for hydrological ensemble forecasting (He et al, 2009;Wetterhall et al, 2011;Cloke et al, 2012).…”