关于我国华北沙尘天气的成因与治理对策

Causes of Sand-stormy Weather in Northern China and Contral Measures

20 0 0年春季 ,我国华北沙尘天气次数陡增 ,影响广泛 ,损失明显增加。利用长期气象观测数据 ,结合遥感和 GIS技术 ,对今年华北沙尘天气的成因进行分析 ,提出造成沙尘天气的原因在于 :1北方地区大风日数的增减是气候周期性变化的反映 ,今年强沙尘天气陡增是因为处于反厄尔尼诺事件的高峰期所致 ;2我国北方地表覆被状况局部改善、整体恶化也是今年强沙尘天气产生的另一重要原因。影响华北地区的沙尘天气主要发源于内蒙古中西部和河北西北部 ,发源地及沿途地表粉尘是沙尘的主体 ,城市扩展区域的地表裸土与建筑沙石则提供了就地扬沙的物质来源。对今后一个时期内沙尘天气的发展趋势进行分析 ,认为 :在全球增暖和我国北方地表植被状况没有根本好转的情况下 ,今后如再逢反厄尔尼诺事件等引起的强冬季风年 ,甚至可能出现更严重的沙尘天气。为此提出建议 :做好科学的还林还草工作 ,大范围地恢复自然植被 ,为京津地区建立减轻和防止沙尘灾害的有效生态屏障。同时治理城市周边地区 ,抑制就地起沙 ;西部开发应重视生态环境建设 ,把生态效益、经济效益、社会效益结合起来考虑 ;建立和完善沙尘天气的动态监测和预警系统 ,做好防灾减灾的科学研究工作。

In northern China, the number of days with sand stormy weather has been decreasing in the past 40 years, but in the spring of 2000, an unprecedented heavy sand stormy weather with high frequency took place, which exerts adverse effect on traffic, environmental management and people's daily life and work. Especially, it brought direct damage to Beijing, Tianjin and their neighbouring areas, which has aroused even more extensive concern of personages of various circles. Therefore, the reasons and the rational suggestions are proposed in this paper. The sand stormy weather is the result of the special geographic environment and weather conditions. Changes in the number of days of strong wind are the reflections of the periodical change in climate. Why the strong sand stormy weather took place is that the anti El Nin～o case is at top, and the land cover deteriorates in the whole area but with part area improving. The dust weather mainly originated from mid west Inner Mongolia and northwest of Hebei Province. The dust is mainly consisted of soil dust from the origination area and the trace. The ground bare soil and sandy dust from construction site in urban extension areas also supplied materials for the local dust. In order to alleviate and control the dust damage, some suggestions were proposed as following: Firstly, the natural vegetation must be restored through planting tree or grasses in cultivated land instead of planting crops. Especially effective ecological protective shield must be established for Beijing and Tianjin city. The bare land of urban marginal areas must be treated in order to control local dust. Secondly, eco environmental construction must be paid more attention to during implementing Western Development Plan. Ecological benefits must be combined with economic and social benefits. Finally, the system for monitoring and predicting the sand stormy weather must be established and improved. Study on controlling and alleviating the dust disaster also need to be done.