不同代表濃度途徑情境對水稻作物灌溉用水量之影響評估

Evaluating the Effects of RCPs on the Irrigation Water Requirements of Paddy Rice

姜世偉(Shih-Wei Chiang)

《農業工程學報》 62卷4期 (2016/12) Pp. 99-111

https://doi.org/10.29974/JTAE.201612_62(4).0007

摘要

本研究基於政府間氣候變遷專門委員會(IPCC)第五次評估報告(AR5)中四組「代表濃度途徑」之未來變遷情境，利用由臺灣氣候變遷推估與資訊平台計畫(TCCIP)進行大氣環流模式(GCMs)統計降尺度所推估未來2020至2100年之月溫度、雨量資料，並以臺灣南部嘉南地區為研究案例，探討在不同氣候變遷情境下對水稻作物灌溉用水量之影響。研究中，將各情境模式所預測之降雨量以及溫度改變因素納入考量，再利用CROPWAT模式進行灌溉用水量之計算。計算結果顯示，在溫室氣體高度排放的情境下，用水量差異增加的趨勢較為明顯，且隨推估時段而上升。針對RCP8.5情境在2081-2100推估時段，由41個GCMs所計算之平均用水量，一期作與二期作分別增加10.69%與6.68%。由符合臺灣降雨特性的5個GCMs計算所得之用水量，一期作增加11.40%-16.84%；二期作增加2.36%-12.48%。

關鍵字

氣候變遷 ； 代表濃度途徑 ； CROPWAT ； 灌溉用水量

並列摘要

This study applied the four Representative Concentration Pathways (RCPs) adopted by the Intergovernmental Panel on Climate Change (IPCC) in the fifth Assessment Report (AR5) to explore the impact of different climate change scenarios on the water irrigation requirements of paddy rice. For this, parameters related to climate were provided by the Taiwan Climate Change Projection and Information Platform (TCCIP). These included statistically downscaled estimates of precipitation and temperature generated by General Circulation Models (GCMs) for the years between 2020 and 2100. The Chia-Nan area in southern Taiwan was selected as the study site, and changes in water requirements were predicted using CROPWAT modeling software, inputting GCM-based precipitation and temperature data as covariate predictors. Results of the study case indicate that the water requirements of paddy rice are likely to increase with time period and greenhouse gas emission under climate change. Specifically, under scenario RCP8.5 (2081-2100), the results showed that the average water requirements from the 41 GCMs data are likely to increase by 10.69% and 6.68% for the first and the second paddy crop, respectively. The water requirements from the top 5 GCMs data suggested for Taiwan are likely to increase from 11.40% to 16.84% for the first paddy crop and from 2.36% to 12.48% for the second paddy crop.

並列關鍵字

Climate change ； RCP ； CROPWAT ； Irrigation water requirements