Abstract
A newly developed flood inundation simulation model targeting to low-lying agricultural watersheds adopted Topographically Adjusted Cells (TAC) to calculate floodwater movement. The TAC is characterized by irregular shaped polygonal cells which are bounded by linear structures such as roads or elevation gaps. These features result in higher calculation efficiency and reproducibility through the avoidance of unnecessary numerical grid allocation and having the linear boundaries possess elevation values. Despite these advantages, the simulation model with TAC has not been widely used due to the cost in terms of labor and time involved in the acquisition and arrangement of the geometric attribute of the cells. To overcome these technical hurdles, we developed a method to create TAC using GIS functions and to prepare complex geometric attribute data with calculation algorisms. This paper introduces the labor and time-saving method to arrange TAC based on the example of watershed model that the we developed.
