| 摘要: | 近年來全球在氣候變遷的作用下，極端氣候頻繁的發生在世界各地，臺灣也不例外，本就不易調配的水資源在這樣的情況下變得更困難。2020年臺灣因夏季無颱風侵台，水資源不足導致農業用水有部分停灌的情形，而臺灣桃園地區因地形特殊，區域內有許多埤塘組成的灌溉系統，可視為多個小型水庫在灌溉時提供水資源，本研究以桃園大圳第十支線作為研究區域，運用系統動力學模式VENSIM建立灌溉系統，透過模式評估整體灌區埤塘調蓄能力及模擬將用水量較大的水稻田部分改採精密滴灌降低灌溉水量並搭配埤塘調蓄系統以應付缺水年水量不足情況，並得出需要改採精密滴灌系統的農田面積比例。
根據模擬結果，2020年一期作若能有效運用所有埤塘蓄水量，將可大幅降低灌區缺水情況，2020年二期作由於大圳供水僅約計畫供水量27%且期作後45天停灌未供水，即便完全運用埤塘蓄水量，仍無法避免灌區缺水情形，若要單純提升埤塘有效容量來應付2020年二期作缺水情形，則合計需濬深約130萬立方公尺，如採取將五個調蓄能力較差之灌區，從水稻田改種植精密滴灌蔬菜，改種面積約34.09%，即便未增加供水量，剩餘灌區僅有四個灌區有零星缺水情況發生，建議可積極推行改耕作較為省水的作物搭配省水灌溉措施，並濬深灌區調蓄能力較差之埤塘。;In recent years, under the influence of climate change, extreme weather has occurred frequently around the world, and Taiwan is no exception. Water resources that are already difficult to allocate have become more difficult in such situations. In 2020, there will be no typhoon invading Taiwan in summer in Taiwan, and the lack of water resources will lead to the partial suspension of irrigation of farm water. However, because of the special terrain in Taiwan′s Taoyuan area, there are many irrigation systems consisting of ponds in the area, which can be regarded as water resources provided by several small reservoirs during irrigation. This study takes the tenth branch line of Taoyuan Canal as the research area, and uses the system dynamics model VENSIM to establish an irrigation system, evaluate the overall irrigation capacity of the pond irrigation system through a model, and simulate the use of precision drip irrigation to reduce irrigation water volume in rice fields with high water consumption, couple the pond irrigation system to cope with water shortage in water shortage years, and determine the proportion of farmland area that needs to be replaced with precision drip irrigation system.
According to the simulation results, if all the water storage capacity of the ponds can be effectively used in the first phase of 2020, the water shortage in the irrigation area will be greatly reduced. In the second phase of 2020, the canal water supply is only about 27% of the planned water supply and the water supply has not been stopped 45 days after the operation. Even if the water storage capacity of the pond is fully used, the situation of water shortage in the irrigation area can not be avoided. If we simply increase the effective capacity of the ponds to cope with the water shortage in the second phase of 2020, in total, the depth of water is about 1.3 million cubic meters. If the five irrigation areas with poor regulation and storage capacity are changed from rice fields to precision drip irrigation vegetables, the planting area is about 34.09%. Even if the water supply is not increased, only four irrigation areas in the remaining irrigation areas have sporadic water shortage. It is suggested that we can actively promote the cultivation of more water-saving crops with water-saving irrigation measures, and the deep irrigation area with poor regulation and storage capacity. |
