Sand-dust storms in and around the Ordos Plateau of China as influenced by land use change and desertification
Sand-dust storms in and around the Ordos Plateau of China as influenced by land use change and desertification
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DOI：
10.1016/j.catena.2005.12.006
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发表时间：
2006-03
期刊：
影响因子：
6.2
通讯作者：
Jiongxin Xu
中科院分区：
文献类型：
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作者：
Jiongxin Xu
风蚀引起的沙尘暴的发生是加速土地退化的一个过程，也可被视为荒漠化的一个指标。因此，揭示这两种现象之间的互动关系，具有重要的理论和实践意义。利用鄂尔多斯高原及其周边地区的资料，研究了土地退化和土地利用变化对沙尘暴的影响。在这项研究中，我们报告了沙尘暴频率和土地退化指数（Id）之间的非线性关系，土地退化指数被定义为荒漠化土地总面积的百分比。利用这种非线性关系，建立了Id=30%的阈值，当Id = 30%时<30% sand-dust storm frequency does not change with increasing Idbut when Id>，沙尘暴频率迅速增加。这一临界值的存在意味着当人为活动指数超过30%时，沙尘暴发生频率会急剧增加。将邻近地区年沙尘暴日数时间序列与伊克昭盟年大风日数时间序列和耕地面积时间序列进行了比较，建立了多元回归方程。利用该方程估算出土地利用和年大风日数变化对沙尘暴日数变化的相对贡献率分别为59.7%和40.3%。表明沙子的频率-在生态脆弱区，通过减少耕地面积和恢复天然草原植被，可以有效地减少沙尘暴在干旱和半干旱气候中。
The occurrence of sand-dust storms induced by wind erosion is a process that accelerates land degradation and can also be considered as an indicator of desertification. Thus, it is of significance both in theory and in practice to reveal the interaction between these two phenomena. Based on data from the Ordos Plateau and its surrounding areas, a study has been made of the effect of land degradation and land use changes on sand-dust storms. In this study, we report a non-linear relationship between sand-dust storm frequency and the index of land degradation (Id), which is defined as the percentage of the area of total land that is desertified. Using this non-linear relationship, a threshold at Id=30% is established such that, when Id<30% sand-dust storm frequency does not change with increasing Idbut when Id>30%, sand-dust storm frequency increases rapidly. This existence of such a threshold means that sand-dust storm frequency would increase abruptly when the human-induced Idexceeds 30%. The time series of annual number of sand-dust storm days in the neighbouring area has been compared to the time series in the annual number of strong wind days and the time series in the area of cultivated land in Yikezhao Meng, and a multi-regression equation has been established. Based on the equation, the relative contributions of the variations in land use and in annual number of strong wind days to the variation in annual number of sand-dust storm days have been estimated as 59.7% and 40.3%, respectively, indicating that the frequency of sand-dust storms may be effectively decreased by reducing the area of cultivated land and restoring the natural steppe vegetation in ecologically fragile areas in arid and semi-arid climates.