台灣位處於西太平洋熱帶氣旋經常侵襲之地區，平均每年會有3至4個颱風經過與影響。近年來由於氣候變遷，降雨強度更強的極端水文事件也更頻繁地出現，每當易淹水地區遭逢颱風、暴雨事件的侵襲皆會造成人民重大的生命財產損失，而台灣地狹人稠的限制，加上高經濟價值的產業發展，更使得淹水造成的經濟損失劇增。政府單位為了減少水患，經常需編列龐大的治水預算來建造水利防洪建設，而隨著近年來經濟的衰退，政府財源日益拮据，治水卻是一個不能減少的支出，因此，除了大興土木地興建昂貴的滯洪池、堤防等水利設施，也應思索其他節省預算的配套措施。在前人研究中，沿海低窪地區的魚塭被證實具有滯洪的效果；而在颱風豪雨事件來臨前，配合預先排放的措施，也能有效的降低排水幹線的負擔，減少溢堤的風險。
因此，為了檢視魚塭預排操作所帶來的效益，本研究以台灣西南部不包含曾文水庫之曾文溪流域與鹽水溪流域作為研究區域，利用地文性淹排水模式(PHD Model)和台灣颱洪災損評估系統(TLAS)做結合，進行不同重現期距下的降雨模擬，並利用不同預排情境來做分析，進而求得預排操作在各情境下所能改善的淹水面積、深度與淹水所造成的經濟損失。
本研究之結果顯示，在不同重現期距降雨與預排深度的情境下，魚塭預排之操作在越低的重現期距降雨下能帶來越大的淹水改善效益，而隨著降雨的重現期距增加，所能改善的效益逐漸下降。

The heavy rainfall of Typhoons usually causes nationwide floods, in turn, yielding huge loss of human lives and economics. Taiwan is located in the zone where active tropical cyclone frequently forms in the western Pacific Ocean, so rainfall intensity is typically high yet with very short the concentration time of flow. The growth rate of the population has also increased rapidly in the urban area. The economic loss caused by flood disaster would be higher in the urban area compared to rural area. Therefore, to reduce the loss casing by flood is the main issue for disaster prevention policymakers. There are different measures in flood preventing. Building detention ponds is one of the common counter-measure to reduce the damage of flood, but most of them cost time, land and budget to construct. Fish ponds or fallow land are also known to be used as a temporary detention pond with relatively low cost.
In order to examine the economic benefit of using fish ponds as a temporary detention pond under different water depth remain in the fish ponds, this study uses the PHD model (Physiographic Drainage-Inundation Model) and the TLAS (Taiwan Typhoon Loss Assessment System) to simulate the property loss due to flood in different return period events. This study choose part of the Chia-Nan plain as an illustrative sample of an area that which is a flood potential area during typhoon and heavy rainfall events. The study area includes Zengwun River watershed and Yanshui River watershed. The study area is about 1,138 km^2.
The results indicate that with higher return period of the rainfall events, the more flood-containing space in the fish ponds is beneficial to reduce the economic loss. Under different return period of rainfall period, there will be a suitable amount of water should be adjusted before the events occur. Results also show that the benefit of pre-drainage operation in fish ponds decreases when the rainfall intensity increases. From the results, we can provide a reference for better prevention and mitigation operation before and during heavy rainfalls in the future.

1. 于宜強、李宗融、龔楚瑛(2014)，「颱風豪雨災害預警與情境分析計畫成果報告」，國家災害防救科技中心。
2. 王如意(2003)，「水災損失評估系統模式之建立（2/2）」，經濟部水利署研究計畫報告。
3. 呂育勳、蔡長泰、顏沛華、吳慶現(1995)，「淹水數學模式之實驗研究」，第四十三卷，第二期，第37-44頁。
4. 巫孟璇(2013)，「地文性淹水即時預報模式之發展與應用」，博士論文，國立成功大學水利及海洋工程研究所。
5. 巫孟璇、蔡智恆、陳金諾、蔡長泰(2010)，「暴潮對沿海地區淹水潛勢與淹水風險之影響」，中國土木水利工程學刊，第二十二卷，第四期，第387-398頁。
6. 李欣輯、陳怡臻、郭玫君(2013)，「台灣颱洪災害損失評估系統之建置」，國家災害防救科技中心。
7. 李欣輯、魏曉萍、劉俊志、楊昇學、葉克家、黃嬿蓁(2013)，「極端降雨事件之淹水模擬分析與損失評估」，國家災害防救科技中心。
8. 張向寬、欉順忠、賴進松、譚義績(2013)，「魚塭區域之排洪特性與防止溢堤方案」，農業工程學報，第59卷第1期，第15-25頁。
9. 陳德豪(2010)，「豪雨期間魚塭排水特性之研究及其對區域排水系統之影響評估」，碩士論文，國立台灣大學生物環境系統工程學系。
10. 楊昌儒(2000)，「地文性淹水預報系統建構之研究」，博士論文，國立成功大學水利及海洋工程研究所。
11. 楊昌儒、蔡智恆、蔡長泰(1998)，「應用地理資訊系統評估水災害損失」，中國土木水利工程學刊，第十卷，第一期，第93-100頁。
12. 經濟部(2011)，「易淹水地區水患治理計畫」。
13. 經濟部水利署水利規劃試驗所(2006)，「區域排水整治及環境營造規劃參考手冊」。
14. 經濟部水利署水利規劃試驗所(2012)，「都市防洪示範區之研究-以台南市為例」。
15. 蔡佳典(2003)，「都市低窪地區於暴雨期間滯洪池排水操控模擬研究」，碩士論文，國立屏東科技大學土木工程系研究所。
16. 蔡長泰、游保杉、周乃昉、史天元、楊昌儒、蔡智恆(1997)，「地理資訊系統在淹水預警上之應用 (四) 」，國立成功大學水利及海洋工程研究所研究報告，CKHOPJ-97-001。
17. 鄭思蘋(2003)，「都會區颱洪災害損失之分析與評估」，博士論文，台灣大學生物環境系統工程學研究所。
18. 蕭代基，黃星翔，洪銘堅，盧孟明，羅以倫(2007)，「淡水河流域洪災損失機率風險分析」，臺灣經濟預測與政策，第37卷，第3期，第31-53頁。
19. 蘇明道，張齡方，糠瑞林，林美君(2003)，「區域洪災損失評估方法之比較研究」，臺灣水利，第50卷，第2期，第22-28頁。
20. Chen C. N., Tsai C. H., Tsai C. T. (2006), “Simulation of Sediment Yield from Watershed by Physiographic Soil Erosion-Deposition Model,” Journal of Hydrology, 327, pp. 293-303.
21. Chen, C. N., Tsai, C. H., & Tsai, C. T. (2007). “Reduction of discharge hydrograph and flood stage resulted from upstream detention ponds,” Hydrological processes, 21(25), pp. 3492-3506.
22. Cunge, J. A. (1975), “Two-dimension modeling of flood plains,”In: Mahmood, K., and Yevjevich, V. Eds., Unsteady Flowin Open Channel, Water Resources Publication, FortCollins, USA.
23. Inoue, K., Iwasa, Y. and Matsuo, N. (1987), “Numerical analysis of two-dimensional free surface flow by means of finite difference method and its application to practical problems”, Proceedings of ROC-Japan Joint Seminar on Water Resource Engineering, Taipei, pp. 171-190.
24. Iwasa, Y. and Inoue, K. (1982), “Mathematical simulation of channel and overland flood flows in view of flood disaster engineering,” Journal of Natural Disaster Science, 4(1), pp. 130.
25. Li, M.H., Hsu, M.H., Hsieh, L.S. and Teng, W.H. (2002), “Inundation potentials analysis for Tsao-Ling landslide lakeformed by Chi-Chi earthquake in Taiwan,” Natural Hazards, Vol. 25, pp. 289-303.
26. O'Brien, J. S., Julien, P. Y. and Fullerton, W. T. (1993), “Twodimensional water flood and mudflood simulation,” Journal of Hydraulic Engineering, ASCE, 119(2), pp. 244-261.
27. Tsai C. T., Chen, C. N. and Tsai C. H. (2007), “Influence of reservoir flood releasing on inundated potential for downstream area”, The 2nd International Conference on Urban Disaster Reduction, ICUDR, Taipei
28. Wong, J. H., Chen, C. N., Lai, C. Y., Tsai, C. H. and Tsai, C. T. (2004), “Application of GIS linked physiographic inundation model to estimate the influence of land use on flooding potential”, Proceedings of the 6th Interaction Conference on Hydroinformatics, Singapore, pp. 769-776.