农田灌溉对印度区域气候的影响模拟  

Modeled impact of irrigation on regional climate in India

作　　者：毛慧琴[1,2,4] 延晓冬[1] 熊喆[1] 田汉勤[3] 

机构地区：[1]中国科学院大气物理研究所全球变化东亚区域研究中心,北京100029 [2]中国科学院研究生院,北京100039 [3]美国奥本大学林业与野生生物学院,奥本AL36849,美国 [4]环境保护部卫星环境应用中心,北京100094

出　　处：《生态学报》2011年第4期1038-1045,共8页Acta Ecologica Sinica

基　　金：国家重点基础研究发展计划资助项目(2006CB400500,,2010CB950903);国家自然科学基金资助项目(40675048);美国NASA土地覆盖和土地利用变化资助项目(NNX08AL73G_S01)

摘　　要：为满足人类对粮食的需求,全球灌溉农田面积迅速扩张,农田灌溉对区域气候的影响引起广泛地关注。利用区域环境系统集成模式(RIEMS2.0)和最新的土地利用变化资料,选取农田灌溉面积最大的印度区域作为研究区域,进行雨养农田和灌溉农田的对比试验,探讨农田灌溉对区域气候的影响。结果表明:(1)农田灌溉使得印度区域年平均气温降低1.4℃,年平均降水率增加0.35mm/d。农田灌溉对印度区域气候的影响存在明显的季节波动,季风前期及6月份该区域气候对下垫面变化的响应最为敏感;7-9月各气候要素变化较小。(2)农田灌溉使得印度区域地表净辐射增加,且地表净辐射在潜热通量和感热通量之间的分配发生了较大的改变,潜热通量增加,感热通量减少;对地表起冷却作用;同时由于土壤湿度增加,蒸散作用增强,大气中水汽含量增加,潜热不稳定能量增加,导致对流性降水增加。In order to provide food to more than six billion people,global irrigated croplands have expanded dramatically in recent decades.The role of irrigation in modifying the regional climate has been widely recognized in recent studies.India,one of the most intensely irrigated regions of the world,was selected as the simulation experiment region to determine the impact of irrigation on regional climate.Two 11-year（January,1990-December,2000） simulation experiments were conducted by using the Regional Integrated Environmental Model System（RIEMS） version 2 over Indian region：（i） Rainfed cropland（RFC） and（ii） Irrigated cropland（IGC）.We discarded the first year from the January 1990-December 1990 model running as equilibration time,and reported results of the final 10 years（January 1991-December 2000） as differences between the two cases（IGC-RFC）.RIEMS2.0 uses the Biosphere-Atmosphere Transfer Scheme（BATS 1e） as its land surface process scheme.In BATES 1e root zone soil moisture is set to field capacity throughout the year in the irrigated crop area,and the soil moisture is the function of rainfall,evapotranspiration,and soil feature in other non-irrigated areas.Over the 10 year time period,the temporal difference of the two regional climate model sensitivity experiments showed that a regional irrigation cooling effect exists with annual averaged 2 m air temperature decreasing 1.4℃ and the precipitation rate increasing 0.35mm/d at the national scale.From the spatial difference of temperature and precipitation we found that the irrigation effect on climate was not only confined to the near-surface atmosphere in irrigated grid cells,but also spread to adjacent grid cells.The irrigation cooling effect can contribute to the increased latent heat flux and decreased sensible heat flux.The increased precipitation rate depends on the offset between the positive convective rainfall and the negative large scale none-convective rainfall.The positive convective rainfall is intrigued by the two

关 键 词：农田灌溉 区域气候 模拟 

分 类 号：S162[农业科学—农业气象学]