This study investigates rice yield and evaluates potential adaptation measures on field management practices for rainfed rice production under climate change scenarios in the Songkhram River Basin, Thailand. The top-down and bottom-up approaches are combined to evaluate the future climate conditions in the Songkhram River Basin and identify adaptation strategies respectively. An ensemble of four Regional Climate Models (RCMs) bias-corrected using the Quantile Mapping technique was used to project the future climate under two climate change scenarios (RCP4.5 and RCP8.5). The DSSAT crop simulation model was used to simulate rice yield and evaluate the impacts of climate change on rice yield, as well as the feasibility of four adaptation options, which were solicited from four hundred farmers through questionnaire surveys in the basin. The strategies include (i) change in planting date, (ii) change in fertiliser application date, (iii) change in fertiliser application dose, and (iv) supplying irrigation water. Based on the model results, future maximum and minimum temperatures are expected to increase by 2.8 and 3.2 °C respectively under RCP8.5 scenario for 2080s. Although annual rainfall may be unchanged, rainfall patterns will shift earlier in future. Evaluation of adaptation strategies suggest that supplying irrigation water under RCP4.5 and RCP8.5 scenarios respectively are the best strategies to increase rice yield under climate change scenarios. Change in fertiliser application date and change in planting date can increase the future rice yield by 12 and 8%, respectively under RCP4.5 scenario for 2080s. Adjusting the fertiliser application dose may however reduce future rice yield. Although supplying irrigation water can aid the production of rainfed rice, other concerns such as the source of water are involved. The feasibility of adaptation actions would depend largely on available resources and mindset of farmers. Further work is warranted in exploring a combination of adaptation strategies and management plans to combat the adverse impacts of climate change.

这项研究调查了泰国Songkhram流域在气候变化情景下水稻产量的稻米产量，并评估了田间管理实践对雨养稻米生产的潜在适应措施。自上而下和自下而上的方法相结合，以评估Songkhram流域的未来气候条件，并分别确定适应策略。使用分位数映射技术对四个区域气候模型（RCM）进行了偏差校正后，用于预测两种气候变化情景（RCP4.5和RCP8.5）下的未来气候。DSSAT作物模拟模型用于模拟水稻产量并评估气候变化对水稻产量的影响，以及通过流域问卷调查向四百名农民征求的四个适应方案的可行性。这些策略包括（i）改变播种日期，（ii）改变施肥日期，（iii）改变施肥剂量，以及（iv）供应灌溉水。根据模型结果，在2080年代RCP8.5情景下，未来的最高和最低温度预计分别升高2.8和3.2°C。尽管年降雨量可能没有变化，但降雨模式将在未来更早发生变化。对适应策略的评估表明，在RCP4.5和RCP8.5情景下分别提供灌溉水是在气候变化情景下增加稻米产量的最佳策略。在RCP4.5情景下，在2080年代，化肥施用日期的改变和播种日期的改变可使未来的水稻产量分别提高12％和8％。但是，调整施肥剂量可能会降低未来的水稻产量。尽管供应灌溉水可以帮助生产雨养稻米，但还涉及其他问题，例如水源。采取适应行动的可行性在很大程度上取决于可利用的资源和农民的心态。在探索适应战略和管理计划相结合以应对气候变化的不利影响方面，需要做进一步的工作。