水庫蓄水之豐枯會影響其放水勢能,水庫運轉操作時,在不同豐枯之情況下會有不同的目標放水量。運轉規線以水庫水位為界線,將各項不同放水量之適用範圍界定出來。國外水庫庫容量大具越年蓄水效益,一般而言均能滿足計劃供水量無缺水現象。相對的台灣水庫庫容量較小,颱風期間產生大量溢流,不具越年蓄水效應,在水量較少之年份,會產生缺水現象,故需制作減量供水之規線。由於缺水年份少再加上該年度各時段缺水情況並不相同,採用水庫入流量所推求之規線實用性不足。為解決此一困境本論文提出了採用臨界入流量以推求規線,所謂臨界入流量乃指入流量之供水潛能恰等於其目標供水量,本論文並對臨界入流量合成法加以說明。採用臨界入流量以推求規線,推昇了規線制作的簡易度及精準度。
The reservoir level affects its water supply availability. Reservoir operations regulate different target release levels over wet and dry seasons. Reservoir rule curve determines (identifies) the applicable release volume based on the reservoir level. The large capacities of reservoirs in foreign countries yield the over year effect and serve to meet the demand of water regularly. In comparison, reservoirs in Taiwan only have limited capacity, which causes excessive overflows during typhoons and fails to provide the over-year effect. The consequence is water shortages during dry hydrologic years, and a reservoir rule curve to enforce water supply reduction has to be determined. With only a few dry hydrologic years and fluctuating wet-dry time periods, rule curves estimated based on the reservoir inflows are not applicable in practice. To resolve such problem, this research proposes the rule curve estimation based on critical inflows, defined as the water supply potential of inflow volume that equates the target release. Such method greatly improves the ease and precision of reservoir rule curve estimation.