圖書典藏及影音數位平台

近年來氣候變遷現象日益明顯，使得臺灣地區水資源環境呈現大幅變化，水資源問題轉趨複雜，傳統單純以滿足需要為開發要務之水資源規劃思維已然變革。以永續利用為導向，並輔以前瞻性與整體性的全方位水資源規劃，已成為為水利工程施政主軸。在常態供水總量管制前提下，水資源規劃如何兼顧中長期多元水資源規劃、短期緊急及枯旱缺水因應作為，並依實際情況擬定彈性之水資源開發計畫，已成為刻不容緩之重要議題。 隨著水資源系統日趨複雜，台灣地區未來多元化水源開發規劃及其調配運用勢必包括跨流域之多水源、多需求之情況；而全球氣候變遷可能造成之衝擊及調適模擬亦增加了水源調配之困難度；且隨氣候極端化等挑戰加劇，新興與雲端技術之應用需求亦日益顯著，未來水源調配分析應用已無法僅靠既有模式之模擬而滿足。為因應水資源規劃之挑戰及未來水資源開發之需求，並提供完善的模式及運用策略。亟需系統性、整合性及有效率的水資源規劃模式協助分析、規劃及調配策略。另外針對於水資源供水系統之開發、順序與其規模相互影響且複雜，需考量流域環境承載力下之開發排程，以建議水資源最適開發期程，以兼顧經濟發展及環境保護之需求，爰辦理本計畫。

The complexities in both the regional-scale configuration and various operating regulations of the integrated water resources systems in the central area of Taiwan render the evaluation of its water supply situation a very challenging task. This project utilized WRASIM, a generalized regional water allocation model, to simulate daily operations of water resources systems of every basin in this area. The water supply yields in each current system as well as different future scenarios are evaluated. WRASIM, developed based on network flow programming, incorporates required operational characteristics of water resources systems. It is capable of simulating reservoir operating rule curves, peak hydro generation, return flows, environmental instream flow requirement, limited treatment plant capacities imposed by high turbidity of raw water, water transmitting/treatment loss and joint operating rules of a multi-reservoir system. In this project, the model is futher improved in the following aspects: (1) developing automatic input data debugging mechanisms, (2) incorporating the MODFLOW to simulate conjunctive use of surface water and groundwater, (3) equipping the numerical root-finding algorithm of nonlinear euqations to efficiently estimate water supply yield, and (4) allowing iterative simulations with different inflow realizations with the same predefined duration among all historic inflow records. In addition, the water supply yields of different systems simulated in several previous projects are re-evaluated by WRASIM, with the same simulating conditions in previous studies. The results show no differences to the previous projects, which validates that WRASIM is sufficient in modeling the water resources systems in the central area of Taiwan. In order to estimate the up-to-date water supply situation, the inflow records till 2012 in different locations of this area are collected. The latest measured effective volumes and height-area-volume relationships of reservoirs are provided by associated operating organizations, including the Miao-Li Irrigation Association, Taiwan Water Corporation, Taiwan Power Company and Central Water Resources Office of Water Resources Agency. The volumes of public water supplied to different districts in 2012 as well as the capacities of major pipes connecting districts or sub-districts are provided by the Taiwan Water Company. The planned irrational water demands during 1998 to 2013 are provided by the Miao-Li, Taichung, NanTou, Chang-Hua and Yuilin Irrigational Associations. According to these updated conditions, the water supply simulation models are established for four major water resources systems. The evaluations of current water supply situations of these four systems reveal that: 1. The Jhonggang and Houlong Rivers system can only supply the current public water demand of the Maoli district. Trans-district water support from the southern Da’an and Dajia Rivers system is necessary to allow further support to the adjacent Hsinchu district in the north. 2. The Da’an and Dajia Rivers system provides sufficient public water to the Taichung district in its current demand level. Trans-district water allocation to the northern Maoli and the southern Changhua districts ensures that the water utilization efficiency is maximized. 3. The lack of surface water reservoirs in the Wu River Basin compels the Changhua district to withdraw groundwater for its public water demand, which has induced severe landslides and endangered the safety of private properties as well as public infrastructures. 4. The yield of the current Zhuoshui River system is insufficient for the public water demand of the Yuilin district. Enhancement of irrigational efficiency is normally applied to increase public water supply. The under-constructed and planned water resources facilities include the TienHwaHu Reservoir, the trans-basin diversion tunnel from the Dajia River to the Da’an River, the Niaozueitan Artificial Lake and the Hushan Reservoir. The completion of these projects with associated improvements of capacities of public treatment plants, inner- and trans-district pipes will elevate the water supply yields of the four individual systems to 457.5, 1796.0, 215.0 and 418.3 thousands m3/day respectively. Table 1 shows the simulated results of the water supply yields of different systems under individual operating condition. The yields of systems in target year can be regulated from those as shown in Table 1 to 483.9, 1761.7, 415.0, and 378.0 thousands m3/day through joint operation and conjunctive use of groundwater to more adequately satisfy each public district in the year of 2031 and 2041. Tables 2 to 5 show the water yields to different districts under joint operations during different future years. If the TienHwaHu Reservoir and Niaozueitan Artificial Lake cannot be developed and the yields remain the scenario in 2021, it is estimated that 3.48% and 4.49% of the gross industrial out values will be affected due to the lack of stable water supply at the year of 2030.