Trend Analysis of Land Degradation in the Zone along the Great Wall in Northern Shaanxi
Received date: 2001-11-15
Revised date: 2002-03-05
Online published: 2002-07-25
Supported by
National Natural Sciences Foundation of China No.40171007; Knowledge-Innovation Project of IGSNRR, CAS, No. CXIOG-E01-05-03
Through the analysis of historical natural settings in the farming and grazing interlocked zone along the Great Wall in northern Shaanxi Province of China, this study has ascertained that its land degradation is both natural and anthropogenic. The overlay of desertification severity layers interpreted from multi-temporal remotely sensed materials in a GIS, in conjunction with field investigation, has revealed that the spatial extent of desertified land in the area has drastically expanded during the 13-year period in certain localities. Both natural and anthropogenic factors in this study are realistically considered to assess land degradation severity. It is found that desertified area of most of the counties in the study area has exceeded 50% of each county's total area. The percentage is even higher in a few counties. The overall severity of land degradation has worsened during the last 13 years with extremely serious and serious degraded areas accounting for 88.5% of the total study area in 1998. The spatial distribution of the desertified land is uneven in terms of degrees. A comparison of the recent satellite image with historical aerial photographs reveals that the extent of degraded land in the study area has expanded while the overall severity of land degradation has worsened. Confirmed by the field investigation, the desert front in the vicinity of Xincheng, Jingbian County has encroached by over 10 km. In the worst affected region between Yulin and Hengshan, the encroachment is as far as over 40 km. Because of the expansion of the Mu Us Desert and the impact of sandstorms, the Great Wall is no longer the divide between sandy land and loessial area. The worsened desertification is attributed to the intensified conflicts among mounting population pressure, limited land resources, and the fragile ecosystem. Inappropriate human activities such as excessive exploitation of natural resources and malmanagement of land, to a certain extent, have inevitably resulted in the destruction of the environment. Mining activities have been identified as the sole cause of rapid spread of desertification in the vicinities of coalfields. The findings in this study have profound implications on how to reduce the severity of desertification hazard in the study area. As the cause of this problem is both natural and anthropogenic in origin, any measure must deal with problems of rural economic development, especially development of agriculture and animal husbandry for increasing farmer's income. A mechanism should be established to compensate for farmers whose income has dropped as a consequence of diminished land productivity caused by mining-induced degradation in the vicinity. Secondly, environmental laws aimed at controlling desertification and protecting environment should be formulated to mitigate the detrimental influence of human economic activities on land. For instance, in severely degraded, poverty-stricken regions the scattered small villages must be shifted to areas with relatively richer water resources so as to enable natural vegetation to recover, thus reversing the trend of desertification.
LIU Yansui, Jay Gao . Trend Analysis of Land Degradation in the Zone along the Great Wall in Northern Shaanxi[J]. Acta Geographica Sinica, 2002 , 57(4) : 443 -450 . DOI: 10.11821/xb200204009
[1] Al Dousari A M, Misak R, Shahid S. Soil compaction and sealing in AL-Salmi area, western Kuwait. Land Degradation and Development, 2000, 11(5): 401-418.
[2] Johnson D L, Lewis L A. Land Degradation: Creation and Destruction. Cambridge: Blackwell, 1995.
[3] Stoorvogel J J, Fresco L O. Quantification of land use dynamics: an illustration from Costa Rica. Land Degradation and Development, 1996, 7(2): 121-131.
[4] Mabbutt J A. Desertification indicators. Climatic Change, 1986, 9: 113-122.
[5] Chen Jie, Gong Zitong, Gao Shangyu. Identification and analysis of root causes of desertification in semi-arid region of China. The Journal of Chinese Geography, 2000, 10(2): 108-119.
[6] UNDP. China Human Development Report: Economic Transition and the Role of Government. Beijing: China Finance and Economics Publishing House, 1999. 63-65.
[7] Zhou Lihua, Fan Shengyue. Study on cause mechanism and rehabilitative approaches of desertification in China. Chinese Environment Preservation Industry, 2000, (4): 30-33.
[周立华, 樊胜岳. 对沙漠化成因机制和治理途径的思考. 中国环保产业, 2000, (4): 30-33.]
[8] Liu Yansui, Ni Shaoxiang, Zha Yong. Land degradation mechanism and management countermeasures in the sand-blown area of northern Shaanxi Province. Journal of Natural Resources, 1997, 12(4): 357-362.
[刘彦随, 倪绍祥, 查勇. 陕北风沙滩地区土地退化机理与治理对策. 自然资源学报, 1997, 12(4): 357-362]
[9] UNEP. Status of Desertification and Implementation of United Nations Plan of Action to Combat Desertification. 1992. 1-15.
[10] Dong Yuxiang. Assessment of hazard degree and analysis of desertification trend in sandy China. Journal of Desert Research, 1996, 16(2): 127-131.
[董玉祥. 中国沙漠化危险度评价与发展趋势分析. 中国沙漠, 1996, 16(2): 127-131.]
[11] SBSP (Statistical Bureau of Shaanxi Province). Statistical Yearbook of Shaanxi. Beijing: China Statistics Press, 1999. 90-100.
[陕西省统计局. 陕西统计年鉴. 北京: 中国统计出版社, 1999. 90-100.]
[12] Le Houerou H N. Climate change, drought and desertification. Journal of Arid Environments, 1996, 34: 133-185.
[13] Huang Fuxiang, Niu Haishan, Wang Mingxing et al. The relationship between vegetation cover and sand transport flux at Mu Us sandland. Acta Geographica Sinica, 2001, 56(6): 700-711.
[黄富祥, 牛海山, 王明星 等. 毛乌素沙地植被覆盖度与风蚀输沙率定量关系. 地理学报, 2001, 56(6): 700-711.]
[14] Fryrear D W. Soil cover and wind erosion. Transactions of the ASAE, 1985, 28(3): 781-784.
[15] Liu Lianyou. The quantity and intensity of regional aeolian sand erosion and deposition: the case of contiguous region of Shanxi-Shaanxi-Inner Mongolia. Acta Geographica Sinica, 1999, 54(1): 59-68.
[刘连友. 区域风沙蚀积量和蚀积强度初步研究――以晋陕蒙接壤地区为例. 地理学报, 1999, 54(1): 59-68.]
[16] Wu Jianxiong. Dongsheng coalfields afforestation showing initial success. Journal of Desert Research, 1996, 16(2): 207-209.
[吴剑雄. 东胜煤田矿区绿化初见成效. 中国沙漠, 1996, 16(2): 207-209.]
[17] Liu Yuping, Ci Longjun. Driving action of population increase on desertification. Journal of Arid Land Resources and Environments, 2000, 14(1): 28-33.
[刘玉平, 慈龙骏. 人口增长对荒漠化的驱动作用. 干旱区资源与环境, 2000, 14(1): 28-33.]
[18] Liu Yansui. Structural analysis and optimal use of land types in mountainous regions. Acta Geographica Sinica, 2001, 56(4): 426-436.
[刘彦随. 山地土地类型的结构分析与优化利用. 地理学报, 2001, 56(4): 426-436.]
[19] Wang Jingai, Xu Xia, Liu Peifang. Landuse and land carrying capacity in ecotone between agriculture and animal husbandry in northern China. Resources Science, 1999, 21(5):19-26.
[王静爱, 徐霞, 刘培芳. 中国北方农牧交错带土地利用与人口负荷研究. 资源科学, 1999, 21(5):19-26.]
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