The Taiwan Typhoon and Flood Research Institute (TTFRI) of National Applied Research Laboratories (NARLabs) has been working closely with the Central Weather Bureau (CWB) to develop a radar data assimilation technique, introduced from the United States, into a system that is adapted to Taiwan's rainfall characteristics. This system was applied to several typhoon events that caused landslides on the Suhua Highway. The skill score for 6-hour rainfall forecasting on this highway was improved by 20% when this radar data assimilation system was used. Moreover, the improvement of the skill score in the Gaoping River Basin, where landslides also occur frequently, reached 47%. In the future, TTFRI and CWB will cooperate with domestic disaster prevention and rescue agencies to forecast torrential rains and respond quickly to damage caused by these rains, so that human casualties and economic loss can be minimized.

Figure 1. The Radar Data Assimilation System was applied to six typhoon events that occurred in the Suhua Highway region. Consequently, the 6-hour rainfall forecasting accuracy improved by 20%.