圖書典藏及影音數位平台

將依據歷年來颱風期間運轉資料，檢討牡丹水庫洩洪機制（釐清提早洩洪的時間及防洪空間），評估既有的降雨預測模式、降雨逕流預報模式、河川洪水預報模式。以牡丹水庫防洪運轉決策支援及入庫流量預測系統檢討颱洪期間洩洪的時間及防洪空間，評估既有的降雨預測模式、降雨逕流預報模式、河川洪水預報模式，進行防洪運轉決策支援及入庫流量預測。考量工作人力需求龐大，及工作本身的專業性，為期爭取時效及工作順利推展，本中心現階段囿於人力不足，擬以公開客觀評選、限制性招標方式委託國內可提供專門知識服務之自然人、法人、機構或團體辦理。

The reservoir operation of flood control is a complicated issue. The uncertain factors include typhoon pathway prediction, the estimation of rainfall volume and types, soil antecedent condition, and tail water retain. Besides, extreme weather has caused disaster more frequently in recent years, raising the difficulty of reservoir operations. For example, the total rainfall was 868 mm at Mudan reservoir basin during typhoon Morakot in 2009; around 615.5 mm concentrated in 24 hrs. It exceeds the extremely torrential rain level, which is carried out by Central Weather Bureau in Sep 11, 2015. Furthermore, the total inflow was upto 95.71 megatons and the total outflow was upto 96.76 megatons. Both of them are the maximum in history record. The peak inflow rate was 740.92 cms; the peak outflow rate was 689.30 cms (design flow of spillway is 3600 cms). It showed the tense situation during reservoir operation. 　　In the 3rd year of the program, we continue our previous projects including rainfall variance of temporal and spatial analysis, assessment gage station network, mastering Sihjhongsi basin hydrological condition for reducing the probability of flood in downstream, and affording the support of establishing the basic flood control policy-making. Besides, our research team established history events operation simulation system, helping staffs know hydrological conditions in Mudan basin well. The assessment of climate change situation can be a reference for extreme rainfall in the future. Mudan River station was moved to a new location last year. Our research team renews different weights and control area to every single station. There are 31 different weight combinations which could apply to different sudden occurrences. The Landsat 8 satellite image caught on Oct 15, 2015, has been adopted in this year for surface cover determination. We find that there is no obvious change in surface cover compared to last year. The parameters of reservoir inflow simulation system such as curve number (CN), initial infiltration and initial inflow and etc., have been optimized last year. Our research team used four typhoon events (Soudelor, Linfa, Matmo and Fung-Wong) occurred in 2015 and 2014 for further parameter examination and renew. The coefficients of efficiency (CEs) in examination consequences are better than 0.8, which showed the system can simulate reservoir inflow well. The assessment of climate change situations can help Southern Region Water Resource Office and Mudan reservoir control center to formulate strategies and respond to possible shocks in the future. In this project, our research team analyzed the below reports including the 5th assessment report announced by Intergovernmental Panel on Climate Change (IPCC) in Sep 30, 2013, Taiwan Climate Change Projection, 2011, Information Platform (TCCIP) and the top 20 simulated results of typhoon total rainfall. Moreover, Taiwan Water Resources Assessment Program to Climate Change (TaiWAP) is also applied to evaluate climate change. The results show that in the future, the rainfall will decrease about 0.88~0.99 times in dry season, increase about 1.03~1.19 times in wet season at Mudan reservoir basin. Our research team established database by collecting operation records of previous typhoons, and we added reservoir water rating curve, the database evaluated and analyzed by various versions of Rules for Mudan Reservoir Watergate Operation (2011, 2009, 2007 and 2003), Directions for Mudan Reservoir Manipulation (2011, 2009, 2006 and 2003), and the reservoir flood control index (reduction rate of flood and safety ratio of flood mitigation). The data could be references for the future reservoir optimal operation including pre-setting the reservoir detention storage space and the goal of water storage. Furthermore, Mudan Reservoir Simulation Operating System from Historical Events, which is established in our program this year, could help control center staffs to be more familiar with the operation. 27 typhoons were formed in northern pacific this year. Typhoons Noul, Chan-Hom, Linfa, Soudelor, Goni and Dujuan were issued warnings. Typhoons Chan-Hom, Linfa, Soudelor and Dujuan were issued land warnings. Our team successfully assisted Reservoir Management Center to collect weather and hydraulic information, analyze data and provide real-time supports for further decision making this year.