民勤地区近地面沙尘监测系统的建立及其运行的初步评价

Construction of Near Surface Dust Storm Monitoring System in Minqin and Evaluation on its Operation

介绍了建于民勤地区的我国第一套近地面沙尘监测系统的组成、结构和功能。经1 a多运行,该系统取得了良好的沙尘监测效果。初步结果表明:2006年民勤19次沙尘暴平均气溶胶浓度的空间分布遵循幂函数关系,在沙漠和绿洲边缘区气溶胶浓度随着高度的增加显著下降,而在绿洲内部,则随高度增加而上升;在不同下垫面条件下,水平沙尘通量随高度变化也遵从幂函数关系,但在沙漠和绿洲边缘呈显著降低趋势,在绿洲呈平缓上升趋势。从沙漠区至绿洲内部,沙尘通量空间分布的规律一般是:沙漠>绿洲边缘>绿洲。2006年在民勤地区,绿洲边缘的沙尘通量比沙漠区减少了42.0%,至绿洲内部则减少74.42%,表明防风固沙林和农田防护林网对沙尘具有较强的防护功能和减灾作用。

Minqin in Gansu province of China has being concerned by lots of scholars due to its high dust storm emissions and environmental deterioration. In 2005, the first near surface dust storm observing system in China was founded in this region, and the aims are to monitor the dust storm occurrence, transportation and deposition, supplying the monitoring results the other methods cannot acquired. The system mainly includes three towers （built in desert areas, margins of oasis, and inside the oasis）, dust collection instru- ments and meteorological observing devices. The dust collection instruments mainly include self-collection filter-bags, horizontal collection devices and the instruments for TSP （total suspended particles） instantane- ous concentration measures. Preliminary monitoring results on dust occurrence in this region show that the TSP concentration has power function relation with the height; the aerosol concentration in areas of desert and margins of oasis decreases with the increase of height, but increases with height inside the oasis. In addition, the horizontal dust flux also has power function relation with height. The dust concentration de- creased by 42.0 % from areas of desert to the margins of oasis, and decreased by 74.42 % to inside the oasis, which showed high protection function of forest belts in this region.