印度农田扩张对区域气候影响的数值模拟  

Modeled impact of cropland expansion on regional climate in India

作　　者：毛慧琴[1] 熊喆[2] 延晓冬[3] 张丽娟[1] 

机构地区：[1]环境保护部卫星环境应用中心,北京100094 [2]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 [3]北京师范大学地表过程与资源生态国家重点实验室,北京100875

出　　处：《生态学杂志》2016年第6期1627-1634,共8页Chinese Journal of Ecology

基　　金：环保公益项目(201309011);国家重点基础研究发展计划资助项目(2010CB950903)资助

摘　　要：选取耕地面积居世界第二位的印度作为研究区域,利用中国自主研发的区域气候模式(RIEMS2.0)和土地利用变化资料,进行潜在植被和雨养农田的长时间积分模拟对比试验,分析了印度农田扩张对区域气候的影响及其机制。结果表明:农田扩张使得印度区域平均气温升高0.1℃,平均降水强度减少0.1 mm·d^(-1),总降水量减少12.8%;农田扩张的气候效应存在明显区域差异和季节差异,在副热带湿润区气温增加0.5~1.0℃,在干旱和半干旱区气温增加0.3~0.5℃,在热带地区气温则下降;农田扩张使得季风前期和冬季气温分别增加0.5℃和0.2℃;季风后期气温降低0.5℃,季风季节气温没有明显变化;在副热带湿润区、干旱和半干旱区降水明显减少,干旱季节特别是季风前期降水减少最为显著,达到0.3 mm·d^(-1);印度农田扩张使得年平均感热通量增加、潜热通量减少,其中植被的蒸散作用引起的潜热通量的变化,尤其是季风前期潜热通量明显减少,是区域气温升高、降水减少的重要原因;农田扩张使得印度大陆上空(850 h Pa高度)受较弱的辐散环流控制,辐散下沉气流是造成当地气温升高、降水减少的又一原因。With the second highest percentage of farmland in the world,India was selected as the simulation experiment region to determine the impact and the mechanism of cropland expansion on regional climate. Based on global potential vegetation datasets and cropland dataset of HYDE V3,simulation experiments were conducted by using the Regional Integrated Environmental Model System（ RIEMS） version 2. 0 over potential vegetation and rainfed cropland areas of India.The results showed that,at the national scale,over the 10-year time period,the annual averaged air temperature increased by 0. 1 ℃ and the precipitation rate decreased by 0. 1 mm · d^（-1）（ 12.8%）. The climatic effect of cropland expansion varied in different climatic zones and different seasons in India. The temperature increased by 0.5-1.0 ℃ in subtropical humid region,0.3-0.5 ℃ in semi-arid and arid region,and decreased in tropical wet and dry region. The temperature increased by 0.2 ℃ in winter and 0.5 ℃ in pre-monsoon season and decreased by 0.5 ℃ in post-monsoon season,and there was no notable change in monsoon season. The subtropical humid region,semi-arid and arid regions saw the notable decreased precipitation,and dry season saw the decreased precipitation,with the largest of 0.3 mm·d^（-1）in the pre-monsoon season. The increased sensible heat flux,the decreased latent heat flux and the downward flow due to the diver-gence circulation at 850 h Pa resulting from the rainfed cropland expansion can give the reasonable explanation for the increased temperature and decreased precipitation.

关 键 词：农田扩张 印度 区域气候 模拟 

分 类 号：S162[农业科学—农业气象学]