圖書典藏及影音數位平台

近年受氣候變遷影響，臺灣降雨型態漸趨極端，致使乾旱災害發生頻率周期逐漸縮短，甚至每年上半年皆有旱象，對水資源供應已形成威脅，亦提高供水風險。據各國研究顯示，面對氣候變遷對水環境的挑戰，傳統單一領域策略已難以因應，必須建立跨領域合作機制，亦即相關部會共同研擬調適策略，方能有效面對水資源供水風險。由於農業用水占我國整體水資源供應量之7成，實有必要針對水資源運用之情勢，協調水利與農業領域之需求，在降低供水風險與不影響糧食安全下，共創雙贏。故本計畫優先探討水資源與灌區節餘水潛力，並為雙方重要議題之合作機制建立基礎。

In recent years, Taiwan’s rainfall patterns become extreme due to the impact of climate change and lead to the frequency of drought cycle gradually being shortened. Therefore, water supply become a threat to Taiwan. To face the challenges of climate change on the water environment, this project would investigate the conditions for the use of water resources and analyze water conservation techniques including cultivation method improvement, irrigation canal improvement and ridge height increasing. Three types of cultivation method improvement including planting period adjustment, conversion from paddy field to upland field, water-saving irrigation cultivation have been investigated. The results show that the conversion is an efficient way for water-saving and is feasible to promote by 4 practical cases including the organic farm in Hualien County, the irrigation area of Zengwen-Wushantou reservoir, the golden agricultural corridor project and the crop adjustment strategy. In addition, the future scenarios of RCP4.5 and RCP8.5 of 2021-2040 were taken to calculate irrigation water usage by CROPWAT modeling for the 4 regions of North, Middle, South and East of Taiwan. The irrigation water usage of RCP4.5 was estimated to increase by about 166,250×103 m3 for the first paddy crop and an increase of about 56,990×103 m3 for the second paddy crop. The irrigation water usage of RCP8.5 was estimated to increase by about 188,210×103 m3 for the first paddy crop and an increase of about 49,500×103 m3 for the second paddy crop. Overall, climate change has a greater impact on irrigation water usage for the first paddy crop with increasing by about 5%. However, the maximum possible increase in the amount of irrigation water usage would be about 22% for the first paddy crop and about 11% for the second paddy crop. That means that the impact of climate change would be with a high degree of uncertainty to the irrigation water usage in the future. The project suggests short-term works including (1) experiment study of crop conversion/rotation cultivation, (2) comparative analysis of different irrigation methods, (3) development of crop conversion/rotation cultivation model, (4) development of standard operating procedure for cultivation, (5) selection of demonstration area and (6) implement of demonstration and presentation. Finally, the project proposes the recommendations of cooperation for improving water resources and irrigation management in order to face water supply risk in the future.