20世纪90年代中国东北地区荒漠化的发展与区域气候变化
DESERTIFICATION DEVELOPMENT AND REGIONAL CLIMATIC CHANGE IN NORTHEAST CHINA IN THE 1990S
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摘要: 文中利用"吉林省陆地资源卫星遥感信息处理与应用的‘3S’系统",分别解译了20世纪80年代与90年代后期的LANDSATTM遥感信息,经对比分析发现:中国东北西部地区的生态环境在恶化,主要表征为荒漠化(盐渍化和沙漠化)区域发展,并以经向扩展为主,荒漠化从3个方面逼近中国的商品粮基地—吉林省中部松辽平原产粮区,对其构成严重威胁;哲里木盟的新开河与乌尔吉木伦河间的撂荒地明显增加。文中还计算了东北区1981~1988年和1989~1996年两个8a间平均气温和年、季降水量,经对比分析发现:东北区是北半球欧亚大陆的第3个高增温区,该区全年平均气温增高0.7℃以上,其中东北区西部的北段(48~54°N)增温最为明显(1.0℃),中段(44~48°N)增温次之(约为0.9℃);东北区西部的中段是东北区降水减少的敏感带,年降水量平均减少30mm,其年际相对变率为20%~30%;而东北区西部的南段为降水量显著增加地带(42~44°N),年降水量平均增加44mm;东北区西部的北段降水量稍有增加,年平均增加15mm。研究表明,20世纪90年代中国东北区西部对全球变化、全球增暖的区域响应为:土地覆盖类型上的荒漠化经向发展和区域气候变化的暖干倾向,即中国东北区西部干旱化的主要特征。Abstract: By using of a '3S' system of earth resource satellite remote sensing information precessing and application for Jilin Prov ince,we have inver sed and compared Landsat T M data in the 1980s and the late 1990s,and find that the ecological environment in the west of Northeast China is becoming deterioration.The main features are:desert ification(salinization and desertization)area is developing and extending along meridional direction,approaches and threats Songliao Plain in the central part of Jilin Province-one of the most important commoditygrain bases in China from three sides,and discarded farm lands in Xinkai River and ji Moron River Valleys in Jirem League increase clearly.By analysis and comparing the mean temperature and annual and season rainfall during two 8 years 1981-1988 and 1989-1996,we discover that the annual mean temperature increases by more than 0.7℃ in the whole Northeast which is the third high-value area of temperature increase in Eurasia of Northern Hemisphere,the hig hest 1.0℃ in the northzone(48-54°N) of the west Northeast,the next 0.9℃ in the middlezone(44-48°N),the middle zone with annual mean rainfall decrease 30mm and rainfall interannual relative variability 20%-30% is a sensitive belt of rainfall,the southzone(42-44°N) with a year mean increase 44mm is a clear increase belt of rainfall,and rainfall in the northzone increases slightly with a annual mean increase 15mm.The research indicates that the regional response to global change and global warming in the 1990s in the west of Northeast has two main features,i.e.desert ification development of land-cover type along meridonal direction and a warmingdr ying tendency of the regional climatic change.These are the main features of drought in the west of Northeast China.