三北防护林工程区气候变化分析

利用三北防护林工程区内气象站点近52 a气温与降水资料,研究了工程建设前后该区的气候变化特征。结果表明:(1)近52 a工程区增温趋势明显,增温速率为0.346℃/10 a; 1960-1977年为相对低温期,1978-1995年气温逐渐上升,建设后期1996-2011年气温显著增高;增温趋势具有明显的南北分异特征,显著升温区主要分布在工程区北部内蒙古高原、松嫩平原和吉林西部平原。(2)年降水量呈下降趋势,下降速率为3.554 mm/10 a;建设之前降水偏少,建设初期有所增加,1996年以来又呈明显减少趋势;降水变化东西差异明显,东部除嫩江平原、内蒙古阴山地区降水增多外,其他地区普遍减少,而西部大部降水呈增加趋势。(3)工程区气候变化空间差异明显,暖湿化区域主要集中在西部阿勒泰地区、柴达木盆地和东部内蒙古阴山地区、河套平原和松嫩平原,而其他地区如呼伦贝尔草原、大兴安岭山区、辽嫩平原则暖干化趋势显著。

Climate Change in Three-North Shelter Forest Program Areas

Using the temperature and precipitation data from 117 stations in the three-north shelter forest program areas from 1960 to 2011, we compared the characteristics of climate change in the areas before and after the implementation of the project. (1) Temperature in the project areas during the years showed a significantly increasing trend with a warming rate of 0.346°C/10 a. The years from 1960 to 1977 were a relatively low temperature period; temperature increased from 1978 to 1995; and the years from 1996 to 2011 were a significant warming period. The warming trend generally manifested the north-south difference, and the areas for notable increasing temperature mainly concentrated in northern regions such as Inner Mongolia Plateau, Songnen Plain in Heilongjiang Province and Plain of Western Jilin Province. (2) The annual precipitation of the project areas overall showed a declining trend with a decreasing rate of 3.554 mm/10 a. Precipitation was less than normal before the implementation of the project. In the beginning of implementation, there was a slight increase, but after 1996, precipitation performed an obviously decreasing trend. The tendency rate of precipitation distribution showed an apparent east-west difference. Precipitation in eastern regions decreased, while in western regions it showed a widespread increase and in eastern regions like Heilongjiang Songnen Plain and Inner Mongolia Yinshan Mountain area there was a notable increase of precipitation. (3) Spatial variation of climate change was obvious. The main climate changing trend in western regions like Altay Region and Qaidam Basin, and in the east regions of Inner Mongolia, Hetao Plain and Songnen Plain was warming and wetting, while in other regions, such as Hulun Buir prairie, Daxingan Mountains and Nenjiang Plain in Liaoning Province, the trend was warming and drying.