系統動力學與分岔理論之跨流域水資源調度-以濁幹線與北幹線串接為例

Abstract

近年來受全球氣候變遷加劇影響，臺灣降雨時空分佈越發極端，加劇了區域水情旱澇不均的現象，使得既單一水資源系統之水資源面臨嚴峻考驗。為突破天然水文條件限制並提升區域調度性，本研究以「濁幹線與北幹線串接工程」為探討標的，評估集集攔河堰與曾文－烏山頭水庫兩大水資源系統跨流域調度之效益。 本研究運用系統動力學模式，使用2010年至2019年之水文資料進行模式建置。研究設定三大模擬情境：現況情境、濁幹線與北幹線串接情境，以及濁幹線與北幹線串接且增設帶狀調蓄池情境，探討不同情境下對雲林地區與嘉南地區之水資源供需影響。結果顯示，在現況情境下，嘉南地區於枯旱期面臨缺水風險，需啟動停灌機制。導入濁幹線與北幹線串接後，建立之雙向調度機制具備非對稱性互補效益：「北水南引」呈現常態穩定性，十年年平均可南引約1,156萬噸水量，有效降低嘉南地區農業缺水量；「南水北調」則受限於水庫溢流條件，屬機會型機制，十年年平均調度量約200萬噸。若進一步增設帶狀調蓄池，可提高約800萬噸，使「北水南引」平均水量提近至1,964萬噸。 此外，本研究引入分岔理論，將供需比例視為狀態變數，以評估系統的穩定性。結果表明，濁幹線與北幹線串接工程不僅未破壞原灌區之供需平衡，更將缺水區原本震盪的供需比例，收斂至趨近供需平衡點。總結而言，跨流域調度能強化整體水資源系統之抗旱韌性。

Climate change has exacerbated uneven rainfall distribution in Taiwan, challenging independent water resource systems. To enhance regional flexibility, this study evaluates the inter-basin water allocation benefits of the "Cho and North Irrigation Canals Interconnection " between the Jiji Weir and the Tsengwen-Wushantou Reservoir. Using a System Dynamics model validated with 2010–2019 hydrological data, three scenarios were simulated: current status, canal interconnection, and interconnection with a linear detention pond. Results show that under the current status, the Jianan region faces severe drought risks. The interconnection establishes an asymmetric bidirectional allocation: the stable "North-to-South Transfer" provides 11.56 million tons annually to mitigate agricultural losses, while the opportunistic "South-to-North Transfer" supplies 2 million tons. Adding a detention pond significantly boosts the North-to-South transfer to 19.64 million tons. Additionally, applying Bifurcation Theory reveals that the project preserves the original areas water balance while converging the water-scarce areas fluctuating supply-demand ratios toward equilibrium. In conclusion, inter-basin allocation, coupled with detention facilities, effectively strengthens the overall drought resilience of regional water networks.