全球变化中的中国干旱区——响应与趋势  

China's Arid Regions in the Global Change:Response and Trend

作　　者：杨维西[1] 

机构地区：[1]国家林业局防沙治沙办公室,北京100714

出　　处：《林业科学》2008年第8期124-130,共7页Scientia Silvae Sinicae

摘　　要：20世纪80年代中期以来,我国干旱区气候出现明显转折:伴随升温趋势明显,降水较大幅度增加,风力和蒸发力持续减弱,干燥指数有所减低;受其影响,许多河流流量增加、湖泊水位升高,植被逐渐恢复,荒漠化持续扩展趋势初步遏制。20世纪中后期,干旱区的许多内陆河流流量不断减少甚至断流、下游绿洲衰退,其主要原因并非气候变化,而是不合理的人类活动。尽管干旱区降水有较大幅度的增加,但降水的基数原本很小,增加后的降水绝对数量仍然很低,因此,干旱区缺水少雨的基本状况没有改变,干旱-荒漠的景观格局没有改变,生态环境的脆弱性也没有根本性改变。With the global warming, the air temperature in the arid regions in China rose over the past 50 years. A special evidence was that the speed of air temperature rising became much higher since the medium and late term through 1980 to 1990. Meanwhile, precipitation increased substantially, and wind power and the days of gale decreased continually, and evaporation capacity decreased successively. Increase of precipitation and reduction of wind power counteracted the calefactive effect, and resulted in improvement of humid conditions, and increase in river discharge and water level in the arid regions. Area of oases had not decreased, although types, structures and functions of those oases had a continual chang over the past 50 years. Threat against oases was not due to climate change, but to human activities. Under the conditions of precipitation increase as well as artificial protection and control, vegetation condition was improved and expansion trend of desertification was initially contained in the arid regions. Although there were some instances that disaccorded to general trends in some local areas or in some years in the whole arid regions, in the view of general trends, basic conditions in the arid regions were described as above in the context of global change. Despite the substantial increase in precipitation, the base of original precipitation was so small that increased precipitation was still low. As a result, neither the fundamental status as scarcity of water resource and precipitation nor the landscape of drought-desert in the arid regions will change, and vulnerability of eco-environment system will have no fundamental transform in the arid regions.

关 键 词：中国干旱区 全球变化 响应 

分 类 号：S718.5[农业科学—林学]