Significance of variations in the wind energy environment over the past 50 years with respect to dune activity and desertification in arid and semiarid northern China
Significance of variations in the wind energy environment over the past 50 years with respect to dune activity and desertification in arid and semiarid northern China
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DOI：
10.1016/j.geomorph.2006.09.003
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发表时间：
2007-05
期刊：
影响因子：
3.9
通讯作者：
Xunming Wang;Hasi Eerdun;Zijiang Zhou;Xiaoping Liu
中科院分区：
文献类型：
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作者：
Xunming Wang;Hasi Eerdun;Zijiang Zhou;Xiaoping Liu
利用20世纪50年代至21世纪初中国339个气象站的气候资料，对北方干旱半干旱地区的风沙活动进行了研究。结果表明，在年代际尺度上，该地区的侵蚀力变化很大。中国北方干旱、半干旱地区多为中低风能环境。20世纪80年代以后，侵蚀力只有以前的20%~ 50%，这种差异对这两个时期观测到的环境变化产生了显著影响。沙丘流动性指数与观察到的沙丘活动是一致的。20世纪80年代后，沙丘活动减少，在一些沙漠与植被沙丘系统在20世纪70年代大多数沙丘柱基活跃，直到20世纪80年代，之后只有波峰是活跃的。在移动的沙漠边缘形成的一些移动的沙丘被半固定沙丘或固定沙丘所取代。由于我国北方干旱、半干旱地区的沙丘植被区多为农牧交错带，监测结果表明，该地区的荒漠化趋势与侵蚀力和沙丘活动趋势基本一致。荒漠化在很大程度上受到气候变化的控制，特别是受到风能波动的控制。
Climate data from 339 meteorological stations collected from the 1950s to the early 2000s was employed to discuss aeolian activity in arid and semiarid northern China. The results show that at decadal time scales, erosivity varied greatly in this region. Most of arid and semiarid northern China was characterised by environments with moderate to low wind energy. After the 1980s, the erosivity was only 20 to 50% of that beforehand, and this difference had a significant impact on the environmental changes observed during the two periods. The dune mobility index was consistent with the observed dune activity. After the 1980s dune activity decreased and in some deserts with vegetated dune systems during the 1970s most of the dune plinths were active until the 1980s, after which only the crests were active. Some mobile dunes that had developed at the margins of mobile deserts were replaced by semi-anchored or anchored dunes. Because most desert areas with vegetated dune systems in arid and semiarid northern China are used for farming or grazing, the results of our monitoring show that the desertification trends were consistent with the trends in erosivity and dune activity in this region. Desertification was controlled much more by climatic changes than has previously been acknowledged, and especially by fluctuations in wind energy.