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我国是沙尘暴易发的国家 ,进入９０年代以来 ,沙尘暴有频率增加、强度加大、范围扩展、危害程度加剧的趋势。据统计 ,我国发生强沙尘暴的次数 ,５０年代为５次 ,６０年代为８次 ,７０年代为１３次 ,８０年代为１４次［１］ ,９０年代为２３次［２］ ,呈明显上升趋势。沙尘暴的
China is a country prone to sandstorms. Since the 1990s, the frequency of dust storms has increased, the intensity has been increased, the scope has been expanded, and the degree of harm has been aggravated. According to statistics, the number of strong sandstorms occurred in China was 5 times in the 1950s, 8 times in the 1960s, 13 times in the 1970s, 14 times in the 1980s and 23 times in the 1990s [2], showing a clear upward trend . Sandstorm