台灣水資源的問題越發嚴重，平均年降雨量約是世界平均值的3.5倍，但國人平均分配到的年水量只有世界的1/7，再加上人口稠密、都市化效應、降雨型態改變以及地形陡峻等因素，結果造成水資源保存不易，更因為降雨集中往往造成雨季時河水暴漲以及淹水等嚴重問題，以往年的統計來看豐枯水年從19年循環逐漸變為7年循環，並且極端數據越來越多，這情況在2013年後越發明顯，而隨著降雨強度增加，更要面臨低窪地區淹水和山坡地發生土石崩落的機率增加等潛在危機，因此分析流域中水文變化情形變為很重要的課題。
為此本研究選定新竹鳳山溪流域為研究區域，蒐集流域相關資料後，以GMS進行水文模式的地表地下水之網格建模，再以HEC-HMS模擬山區地表逕流，最後用水文模式WASH123D(WaterSHed Systems of 1-D Stream-River Network, 2-D Overland Regime, and 3-D Subsurface Media)進行該研究區域的校準與驗證，結果顯示模擬使用之參數適用於此流域，因此此模式可拿來做為鳳山溪流域中之後續研究使用。
接著以台灣氣象局季長期氣候預報結合氣象合成模式WGEN繁衍出未來的降雨情況當作氣象參數輸入WASH123D，探討模式對於季節性預報的適用性，分析結果顯示，每個月地下水位受到前一個月的雨量影響很大，所以若季長期氣候預報之結果不準確，則模擬之結果就會出現高估或低估地下水位之情況，所以雨量預報的準確與否是影響模擬結果很重要的因素。

The problem of water resources in Taiwan is becoming more and more serious. The average annual rainfall is about 3.5 times the world average, but the average distribution of water for a person only equals world’s 1/7. The records show that the cycle period of wet and dry has gradually changed from the 19 year to 7 year. This situation became more apparent after 2013, with the increase of extreme rainfall events, flooding and the landslides threaten people’s life and property. Therefore, analysis of hydrological changes in the basin becomes a very important issue.
This study chooses Hsinchu Fengshan River basin as the study area. Surface runoff of mountain area was simulated with HEC-HMS model, and WASH123D model was applied for the simulation of hydrologic fluxes, including river water level and groundwater flow. The results revealed a good performance on model simulation, and then used these setups for further groundwater flow simulation. The next step use the seasonal climate outlooks, issued by Taiwan Central Weather Bureau, incorporated with the approach by combining WGEN model and WASH123D model. The results show that the monthly groundwater flow is greatly affected by the rainfall of the previous month. So if the seasonal climate outlooks are not accurate, then the simulation outcome will be overvalued or underestimated. Therefore, the accuracy of the seasonal climate outlooks is an important factor influencing the simulation outcome.

參考文獻
1. Chow, V. T., Mays, D. R., Mays, L. W., “Applied Hydrology.” , McGraw-Hill, New York . (1988).
2. Domenico, P. A. and F. W. Schwartz., Physical and Chemical Hydrogeology, John Wiley & Sons, New York, pp. 824. (1990).
3. Haith, D. A., Mandel, R. and Wu, R. S., “Generalized Watershed Loading Functions Version 2.0: User’s Manual.”, Department of Agricultural and Biological Engineering, Cornell University, Ithaca, NY. (1992).
4. Halwatura, D., Najim, M. M. M., “Application of the HEC-HMS model for runoff simulation in a tropical catchment. ” , Environmental Modelling & Software, Vol. 46, pp. 155-162. (2013).
5. Huang, G., and Yeh, G. T., “Integrated Modeling of Groundwater and Surface Water Interactions in a Manmade Wetland. ” , Terr. Atmos. Ocean. Sci., Vol. 23, No. 5, pp. 501-511. (2012)
6. Lina, K. P., Choua, P. C., Shih, D. S., “To Study Hydrological Variabilities by using Surface and Groundwater Coupled Model – A Case Study of PingTung Plain, Taiwan. “ , Procedia Engineering, Vol. 154, pp. 1034-1042. (2016)
7. Pickering, N. B., Stedinger, J. R., Haith, D. A., “Weather input for nonpoint source pollution models.”, Journal of Irrigation and Drainage Engineering, 114(4),pp.674-690. (1988).
8. Richardson, C. W., Foster, G. R., Wright, D. A., “Estimation of erosion index from daily rainfall amount.”, Transactions of the ASABE, 26(1),pp.153-156. (1983).
9. Shih, D. S., Liau, J. M., Yeh, G. T., “Model Assessments of Precipitation with a Unified Regional Circulation Rainfall and Hydrological Watershed Model. “ , American Society of Civil Engineers, PP. 43-54. (2012)
10. Soltani, A., Latifi, N., Nasiri, M., “Evaluation of WGEN for generating long term weather data for crop simulations.” Agricultural and Forest Meteorology, Volume 102, Issue 1, pp. 1-12. (2000)
11. Taulis, M. E., Milke, M.W., “Estimation of WGEN weather generation parameters in arid climates.” Ecological Modelling, Volume 184, Issues 2–4, pp. 177-191. (2005)
12. Yeh, G. T., Shih, D. S., Cheng, J. R. C., “An integrated media, integrated processes watershed model. ” , Computers & Fluids, Vol. 45, pp. 2-13. (2011)
13. Yeh, G.T., Huang, G.B., Zhang, F, Cheng, H.P., Lin H.C.,“WASH123D: A Numerical Model of Flow, Thermal Transport, and Salinity, Sediment, and Water Quality Transport in WAterSHed Systems of 1-D Stream-River Network, 2-D Overland Regime, and 3-D Subsurface Media. ” Technical report Submitted to US EPA. Department of Civil and Environmental Engineering, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL. (2005).
14. 水利署第二河川局：http://www.wra02.gov.tw/mp.asp?mp=102 (2017)
15. 水利署地理資訊倉儲中心：http://gic.wra.gov.tw/gic/HomePage/Index.aspx (2017)
16. 水利署電子報，「氣候變遷進行式 雨，超載了！」，第36期 (2013)
17. 台灣颱風洪水研究中心：http://www.ttfri.narl.org.tw/ (2017)
18. 朱容練、朱吟晨、林士堯、劉俊志、陳永明，「2014-2015 年乾旱事件概述」，國家災害防救科技中心災害防救電子報，第124期 (2015)
19. 江介倫，「地理資訊系統及HEC-HMS 應用於中小集水區降雨逕流模擬」，坡地防災學報，8(2)，pp. 29-44. (2009)
20. 柳文成，「結合HEC-HMS與調適性模糊類神經網路模式於不同預報時間之逕流模擬」，台灣水利第62卷第四期，pp.43-54 (2014)
21. 張惠成，「河川泥砂沖淤機制與濃度傳遞模擬分析研究」，碩士論文，國立中興大學土木工程學系 (2016)
22. 童新茹，「結合季長期天氣預報與水文模式推估石門水庫入流量」，碩士論文，國立中央大學水文與海洋科學研究所 (2011)
23. 黃旭杰，「以產業觀點建構區域供水系統之氣候調適能力」，碩士論文，國立臺灣大學生物環境系統工程學研究所 (2016)
24. 彭柏文，「櫻花鈎吻鮭棲地氣候變遷衝擊評估與季節性預警系統建立」，碩士論文，國立臺灣大學生物環境系統工程學研究所 (2011)
25. 葉震升，「應用三維水文數值模式模擬土地利用及氣候變遷下地下水位變化趨勢－以新竹鳳山溪為例」，碩士論文，國立中央大學土木工程學系 (2016)。
26. 游保杉，2007，「應用氣象展望資料於長期流量預報(二) 」，行政院國家科員委員會專題研究計畫報告。
27. 經濟部水利署，「台灣西部河川河槽作為地下水補注區可行性分析」(2011)。
28. 經濟部水利署：https://www.wra.gov.tw/ (2017)
29. 蔡忠遠，「探討土地利用和氣候變遷下鳳山溪流域地下水位及流量的影響」，碩士論文，國立中央大學土木工程學系 (2015)。
30. 歐信宏，「HEC-HMS降雨-逕流模式應用之研究」，碩士論文，國立成功大學水利及海洋工程學系 (2001)