气候变化会导致作物耗水过程改变，从而影响灌溉需水。研究水稻灌溉需水对气候变化的响应规律，有助于合理制定应对气候变化的灌溉策略，保障水资源可持续利用和粮食安全。该文基于1961－2010年气象数据和HadCM3大气环流模式 A2和 B2两种情景下的统计降尺度模拟结果，利用经田间试验资料验证后的水稻模型ORYZA2000，模拟淹水灌溉和间歇灌溉两种灌溉处理下、历史和未来情景下水稻灌溉需水对气候变化的响应规律。结果表明：过去50年，间歇灌溉和淹水灌溉模式下水稻耗水量呈现显著上升趋势，而水稻灌溉需水量和产量都呈现下降趋势，分别由降水增加和气温升高、辐射下降导致的生育期缩短引起；未来气候情景下，间歇灌溉和淹水灌溉模式下水稻耗水量在未来3个时期（2020s，2050s 和2080s）均呈现不同程度的增加；耗水量的显著增加和降水的减少导致了未来3个时期水稻灌溉需水量的明显增加；受持续增温的减产效应影响，水稻产量在未来3个时期呈现减少趋势，且降幅逐渐变大。% The climate change will cause the alteration of the processes of crop water consumption, and thus affect the irrigation water requirement. As one of the most important crops in China, rice accounts for 18%of the country’s total cultivated area. Therefore, understanding the impacts of climate change on rice water consumption is of great significance. Investigations on response of rice irrigation water requirements to climate change are beneficial to develop adaptation strategies to climate change and thus ensure food security and the sustainable use of water resources. In this study, changes in rice yield and irrigation water requirements in the past five decades (1961-2010) under flood irrigation and intermittent irrigation were investigated using rice model ORYZA2000 based on historical meteorological data. The rice model ORYZA2000 genetic parameters were calibrated and validated using two calibration programs, DRATES and PARAM, built in the ORYZA2000 model based on two years farm experiment data in Kunshan Station. The potential impacts of future climate change on the rice yield and irrigation water requirements were also examined using validated rice model ORYZA2000. Climate data in the future were generated by the HadCM3 (Hadley Centre Coupled Model version 3) of the IPCC 3rd Assessment Report under A2 and B2 emission scenarios. Statistical downscaling method (SDSM) was employed in this study to get future input meteorological data (2011-2099) (including precipitation, daily air temperature, vapor pressure, wind speed, and radiation data) in Kunshan station of the rice model ORYZA2000. Daily NCEP/NCAR reanalysis data sets during the period of 1961–2001 were used to calibrate and validate the SDSM model. The results indicated ORYZA2000 model can be used to simulate the rice index in a relative high accuracy, and thus can be used to conduct the climate change impact assessment. The SDSM performed generally well in reproducing daily meteorological data for input of rice model ORYZA2000. The simulation of changes in related variables during historical period indicated the significant increases in rice water consumption were found during the past decades. However, rice water irrigation requirements and yield present significant decreasing trends because of increasing precipitation and shorten growth duration caused by increasing air temperature and decreasing radiation, respectively. The rice water consumption will increase under both intermittent irrigation and flood irrigation in the future. Irritation water requirements will decrease significantly due to increasing precipitation and rice water consumption in the future. Compared with that in the baseline, the rice yield will experience decrease and the decrease magnitudes will be enlarged over time due to the negative effect from increasing air temperature.
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