三江平原50a来气温及降水变化研究

三江平原位于我国高纬度地区,是受全球气候变化和人类活动影响最显著的地区之一。本文利用三江平原地区范围内的18个气象站点及外围6个站点的长期观测资料,运用趋势系数、气候倾向率等方法分析了该区域的气候时空变化规律。结果表明:50a年来本区气温有显著上升趋势,平均气温以0.303℃.(10a)-1幅度升高。全年各月气温均呈上升趋势,但是冬春季升温最为剧烈,达0.512℃.(10a)-1;夏秋季最弱,仅为0.153℃.(10a)-1。由于最冷月平均温度升高比最热月大,所以导致气温年较差减少。气温升高存在显著的区域差异,西南地区增温强烈,气温倾向率大于0.4℃.(10a)-1;最小的气温倾向率位于西部及南部边缘地区,小于0.2℃.(10a)-1。降水趋势性变化不显著,但是还是呈现弱的减少趋势,平均年降水量倾向率为-8.926mm.(10a)-1。一年中冬季降水增加明显,1月份尤其显著;9月份降水减少明显。

Study on the Changes of Air Temperature and Precipitation in the Last 50 Years in the Sanjiang Plain

In the last 50 years,land use and land cover in the Sanjiang Plain have been changed tremendously.Farmland instead of marsh wetland has become the main landscape.Based on the monthly data of air temperature and precipitation in the last 50 years from 24 meteorological stations in and out of the Sanjiang Plain,the climatic variations and tendencies of the Sanjiang Plain were analysed by calculating climate trend coefficient and climate tendency ratio.The results showed tiat in the last 50 years,there is a 0.303℃·(10a)-1 increase in the annual mean air temperature.Monthly air temperatures are all tending to rise,while increase of air temperature in the winter and spring is higher(0.512℃·(10a)-1) than that in summer and autumn.Rise of air temperature in the cold season is higher than that in hot season,so the yearly range of the air temperature is tending to decrease.The rise in temperature is regionally different.Southwest area has the higher rising degree(>0.4℃·(10a)-1),while the west and south margin area has the lowest rising degree.The change of precipitation is not obvious(<0.2℃·(10a)-1).There is only a little increase tendency for annual precipitation,and the tendency ratio is-8.926mm·(10a)-1.Rise of precipitation in winter is obvious,especially in January,while in September there is a obvious decrease.