中国西部退耕还林(草)和沙漠化土地绿化的区域性气候效应

摘要

中国正在实施的西部大开发必将导致较大规模的土地利用和地表覆盖(LULC)变化,其中最重要的两类LULC变化是退耕还林(草)和沙漠化土地绿化工程.利用最新的全球地表特征资料数据库(GLCCD)识别以上两项生态建设工程的实施规模与范围,并以此更新了目前比较流行的区域气候模式的下边界条件,利用修正的区域气候模式研究上述大规模LULC变化可能对中国区域性气候造成的影响.使用的卫星资源数据库是由美国地质测绘局(USGS)和Nebraska-Lincoln大学牵头,根据NOAA卫星的AVHRR资料、USGS掌据的高分辨率数字化地图,以及生态区划和植被分布等资料组建的.%The West Development Policy being implemented in China causes significant land use and land cover(LULC) changes in West China, of which the two most important types of LULC change are replacingfarmland and re-greening the desertification land with forest or grass. This paper modifies the prevailingregional climate model (RCM) by updating its lower boundary conditions with the up-to-date satellitedatabase of the Global Land Cover Characteristics Database (GLCCD) created by the United StatesGeological Survey and the University of Nebraska-Lincoln. The modified RCM is used to simulate thepossible regional climate changes due to the LULC variations. The preliminary results can be summarizedas that the two main types of LULC variation, replacing farmland and greening the desertification landswith forest or grass in west China, will affect the regional climate mostly in northwest and north China,where the surface temperature will decrease and the precipitation will increase. The regional climateadjustments in South, Southwest China and on the Tibet Plateau are uncertain.