台南、高雄地區穩定供水與減災總合策略研究與成效評估-推估各季節區域農業水資源需求與農業涵養地下水資源之研究(子計畫三)(I)

Climate change refers to changes in long-term climatic characteristics and maylead to exacerbation of short-term climate variability and extreme weather,resulting in a disastrous environment for biological growth on earth. In recentyears, the climate change includes an increase in the frequency of extremeevents and the widening disparity in precipitation and rainfall caused by theunstable hydrological and meteorological conditions. Climatic, hydrological andenvironmental constraints coupled with the growth in water demand in the futurecomplicates the dilemma of regional water supply. In addition, the issue of foodsecurity is also an important issue on a global scale. This research focuses onhow to establish an appropriate paddy field irrigation operation and managementscheme to ensure the effective use of water for agricultural production in Tainanand Kaohsiung area. The temporal distribution of rainfall in wet and dry season inthis area is highly uncertain, as noted in the records. In fact, if the rainfall in thewet season (second half of the year) is not as abundant as expected, it is verylikely to cause water shortages in the first half year of the coming year. Tainanirrigation system and Kaohsiung irrigation system are two different types, basedon the source of water and the distribution of the fields. This research aims toestimate seasonal regional irrigation water demand and the impact of irrigationscheme to the conservation of groundwater resources. The objective is todevelop a field-based water balance model using system dynamics that presentthe characteristics of the system dynamic behavior changing over time for aspecific field unit. Based on the water balance model for a field unit, this researchwill establish the irrigation water system among all the field units in the region.The established Tainan system and Kaohsiung system can provide the impact ofthe irrigation water system to the regional groundwater system, in terms ofgroundwater level, which is an important information in drought relief whengroundwater is the major source of substitute. The findings can be applied as areference for the development of an intelligent drought relief managementstrategy. It can provide insights for the water resource authority to carry out asustainable system operation.