Regulating and analysis of farm pond irrigation system in Taoyuan

The farm pond irrigation system is one of the unique agricultural irrigation features in the Taoyuan area. It not only provides direct or auxiliary irrigation in the field, but also serves as a storage space for excess water during rainfall. This study aimed to establish a farm pond irrigation system using the system dynamic model for the 15 farm ponds and the followed 15 irrigation districts that supplied by No. 10 sub canal of Tao-Yuan Main Canal. The actual irrigation water, rainfall data and hydrological factors in 2017 were applied to simulate crop water demand and analyze the reduction percentage of main canal water supply under 3 scenarios of farm pond operation i.e. full pond adjustment, part pond adjustment and without any pond adjustment models. The result appears that 60% of water supplied by main canal can be reduced under full pond adjustment model. When extreme drought occurred, 80% of total irrigation area must be turned into fallow status to make the crop on the rest area to be cultivated normally. In other words, only 20% irrigation area of crops can be survived through whole crop period under the condition without any precipitation if only irrigated by farm ponds.