Due to the geographical environment and hydrological characteristics, floods caused by typhoons frequently occur in Taiwan. Therefore, how to conduct disaster risk management has become an important issue. Disaster risk management can be divided into two parts: pre-disaster risk management and disaster response. In view of the above, starting from 2016, the Institute has developed the flood damage assessment system and subsequently the flood loss estimation models for various types of land use (including residential, industrial and commercial, agricultural, animal husbandry and public facilities). The Institue continued to refine the models for agriculture, animal husbandry, and aquaculture land use from 2017 to 2019 and established the geospatial data for potential flooding damages in Taiwan, which provides references for applications on flooding loss for a single hydrological event and drainage planning.
The system can not only assess the flood damage of a single event, such as the losses caused by the flooding disasters in Chiayi County on August 23, 2018 (See Figure 1), but when a planning project scheme is selected, it can also estimate the direct loss and indirect loss for various return periods of the planning situation and the current situation respectively. The annual average loss and the benefits from direct loss reduction of the planning situation and the current situation can also be obtained and used as a reference for the selection of engineering planning projects, such as the benefits from direct loss reduction of the Dianbao Creek planning project (see Figure 2). Since the cost of project construction is higher than the cost of planning, if the said concept can be applied to the assessment of the drainage scheme selection, given the limited overall budget, the selection of the planning projects could be more efficient. In addition, the Institute also launched a pilot service of the API circulation of flooding geospatial data for the major river systems in 2019 and provides applications to river risk management assessment.
Figure.1 Flood loss at Chiayi County on August 23, 2018
Figure.2 Benefits from direct loss reduction of the Dianbao Creek planning project