大气中可吸入颗粒物超标是我国当前面临的重要环境问题。地表释放的沙尘颗粒是大气环境中可吸入颗粒物的重要来源，也是大气气溶胶的重要组成部分。为了改善人居环境、降低大气中可吸入颗粒物浓度，准确评估地表释放的沙尘颗粒对大气中可吸入颗粒物浓度的贡献，本文对京津风沙源区各类地表的沙尘释放进行深入研究，确定地表沙尘释放的时空分布，估算到达各典型城市的沙尘量，并对各典型城市的沙尘源进行了解析。获得的主要结论如下： （1）京津风沙源区地表沙尘释放强度及其时空分布 京津风沙源区2000、2005、2010、2015年地表沙尘释放量受气候因子的影响波动变化，依次为3237.52、2764.67、3435.85和3258.51万吨；春季最大，冬季次之，秋季第三，夏季最小，年平均占比分别为45.45%、28.14%、15.99%和10.42%。从空间上看，农牧交错带草原、荒漠草原、晋北山地丘陵亚区地表沙尘释放量占总量的55.29%，而库布齐沙漠、毛乌素沙地、浑善达克沙地和科尔沁沙地这四个沙地（漠）亚区地表沙尘释放量占总量的20.98%。因此，从控制地表沙尘释放的角度，京津风沙源治理应重点考虑前面三个亚区，而不是沙地（漠）亚区。 （2）京津风沙源区地表释尘可能到达8个主要城市的质量 2015年到达京津风沙源区典型城市的沙尘量在空间分布上大致呈现从西到东、从北到南逐渐增加的趋势；到达北京、张家口、赤峰、大同、呼和浩特、锡林浩特、包头、榆林的沙尘量分别为274.49、146.96、151.83、91.03、68.61、65.42、41.46和26.21万吨。其中，0~10 μm可吸入颗粒（PM10）是沙尘量的主体，占到达上述城市的沙尘量的比例介于62.72%~ 92.99%，平均84.16%；对于能够直接进入人体呼吸系统，也是大气环境重点关注的0~2.5 μm沙尘颗粒（PM2.5），占到达上述城市的沙尘量的比例介于25.54%~ 39.68%，平均35.40%。因此，从改善京津风沙源区人居环境的角度，京津风沙源区治理工程的核心是控制PM10，尤其是PM2.5。 （3）京津风沙源区各主要城市的沙尘来源解析 2015年到达各个城市的沙尘总量中，80.52%的沙尘量来源于农牧交错带草原亚区、荒漠草原亚区和燕山丘陵山地水源保护区，4个沙地（漠）亚区仅贡献了9.84%。从土地利用类型上看，对各个城市沙尘量的贡献从大到小的顺序依次是耕地、沙地（漠）和草（灌）地，它们的值分别是576.27、186.30和103.44万吨，对应的贡献率为66.54%、21.51%和11.95%。由此可见，从降低京津风沙源区典型城市大气可吸入颗粒物、改善城市大气环境质量的角度，京津风沙源治理工程应重点关注农牧交错带草原亚区、荒漠草原亚区、燕山丘陵山地水源保护区，而不是沙地（漠）亚区；京津风沙源治理工程应重点关注耕地，其次是沙地（漠），最后是草（灌）地。

Excessive fine particulate matter is one of the most important environmental problems in China. Sand and dust particles released from the surface due to soil wind erosion is an important source of inhalable particles in the atmosphere and an important component of atmospheric aerosols. In order to improve the living environment and reduce the particulate matter concentrations in the atmosphere, determine the contribution of surface dust release caused by soil wind erosion to the concentration of inhalable particulate in the atmosphere, we determined the differentiation of dust release of different land use types in Beijing-Tianjin sand source region in temporal and spacial scale and estimated wind-blown dust arriving in typical cities, analyzed the sources of sand and dust arriving in typical cities. The main conclusions are as follows: (1) Intensity and characteristics in temporal and spacial scale of dust release in Beijing-Tianjin sand source region. In 2000, 2005, 2010 and 2015, the amount of surface sand release in Beijing-Tianjin sand source region changed due to the influence of climate factors, which were 32.38, 27.65, 34.36 and 32.59 million tons, respectively. The amount of dust released in spring is the largest, winter is the second, autumn is the third, and summer is the smallest. They account for 45.45%, 28.14%, 15.99% and 10.42% of the annual average. From the perspective of space, the average annual dust release volume of the farming-pastoral ecotone, desert grassland subregion, north shanxi mountains and hills subregion accounts for 55.29% of the total surface dust release volume in Beijing-Tianjin sand source region. In the Kubuqi desert subregion, Mu Us sandy subregion, Horqin sandy subregion and Hunshandake sandy subregion, the average annual dust release accounts for 20.98% of the total surface dust release in Beijing-Tianjin sand source region. From the angle of controlling the release of sand and dust on the surface, the Beijing-Tianjin sand source control engineering should firstly focus on the farming-pastoral ecotone, desert grassland subregion, north Shanxi mountain and hills subregion, instead of the sandy subregions. (2) The amount of sand and dust arriving in typical cities of Beijing-Tianjin sand source region. The spatial distribution of sand and dust in each city generally shows a trend of gradual increase from west to east and from north to south. The amount of sand and dust arriving in typical cities in the area was ranked from large to small as Beijing, Zhangjiakou, Chifeng, Datong, Hohhot, Xilinhaote, Baotou and Yulin, with 2.74, 1.47, 1.52, 0.91, 0.69, 0.65, 0.41 and 0.26 million tons, respectively. Among them, 0-10μm inhalable particles (PM10) are the main part of the dust amount, accounting for 62.72%-92.99% of the total dust amount in the above cities, with an average of 84.16%. 0-2.5 um particles (PM2.5), which can directly enter the human respiratory system and is also a major concern of the atmospheric environment, accounts for 25.54%-39.68% of the total dust amount in the above cities, with an average of 35.40%. Therefore, from the perspective of improving the human settlement environment in Beijing-Tianjin sand source region, the core of the Beijing -Tianjin sand source control engineering is to control PM10, especially PM2.5. (3) Source analysis of sand and dust arriving in typical cities of Beijing-Tianjin sand source region. Among the total amount of dust reaching each city, 80.52% comes from the farming-pastoral ecotone, the desert grassland subregion and the water source protection area of the yanshan hills, and the four sandy land (desert) subregions contribute only 9.84%. From the perspective of land use type, the subsequence of contribution to the amount of sand and dust in each city is cultivated land, sandy land (desert) and grassland (shrub) land, whose values are 5.76, 1.86 and 1.03 million tons respectively, and the corresponding contribution rates are 66.54%, 21.51% and 11.94%. Therefore, from the perspective of improving the atmospheric environment and reducing the inhalable particles in the urban atmosphere in the Beijing-Tianjin sand source region, the Beijing -Tianjin sand source control engineering should focus on the farming-pastoral ecotone, desert grassland subregion and the water source protection area of yanshan hills, rather than the sandy land (desert) subregions. In addition, the Beijing -Tianjin sand source control engineering should focus on cultivated land, followed by sandy land (desert), and finally grass (shrub) land.