1991-2000年中国北方地面起尘

The Dust Emission of Northern China in 1991-2000

利用美国EPA的起尘公式,本文计算了1991-2000年间中国北方的地面起尘(PM50,粒经小于50μm的颗粒物)分布。结果表明:1991-2000年整体上中国北方的起尘是从西到东减小,起尘的量级变化幅度达5个量级,年起尘总量为9.24×106t。春季是起尘最多的季节,占年起尘总量的一半以上。和1951-1980年的起尘相比,1991-2000的年起尘总量只有1951-1980的年起尘总量的21.5%,最大值所处的位置也由塔克拉玛干沙漠中心向东移动到青海和新疆的交界地区,为0.51 t/(a.hm2)。

In this paper the dust emission（PM50） from the surface during 1991-2000 was investigated.The dust emission rate was calculated with an US EPA formula.The dust emission rate of Northern China mainly decreased from west to east by 5 orders of magnitude in the period of 1991-2000.The annual total dust emission of PM50 in northern China was 9.24×10^6 ton and the spring was the worst dust-emitting season in the area,which took more than half of the annual emission amount.The annual total dust emission of 1991-2000 was only 21.5% that of 1951-1980.The region of the maximum value of the dust emission was shifted eastward from the center of Tarim basin in 1951-1980 to the border of Qinghai Province and Xinjiang Province in 1991-2000 with the value of 0.51 ton/（hector.year）.