1964-2014年玛曲高原土地沙漠化驱动力定量分析

目的]对玛曲高原土地沙漠化的驱动因子进行定量分析,为黄河上游地区沙化草地恢复及生态环境治理提供科学依据和理论基础.方法]以多期玛曲高原遥感数据和近50 a气象及社会经济资料为数据源,采用主成分分析等方法开展研究.结果] 1964-2014年,玛曲高原沙漠化土地的扩张是综合贡献率高达57.18％的自然因素和人为因素共同作用的结果.在不同时段,玛曲高原沙漠化土地扩张的驱动因素不同;1964-1980年,沙漠化土地的扩张以自然因素为基础,人为因素为主导,它们的贡献率分别为33.95％和47.66％;1981-1997年,玛曲高原沙漠化程度的加剧是受自然因素和人为因素共同作用,综合贡献率为42.75％;1998-2014年,玛曲高原沙漠化土地的逆转以人为因素为主导,其贡献率为44.97％.结论]玛曲高原沙漠化土地的演化是在高寒脆弱不稳定的大自然背景下,人为因素尤其是人口数量和牲畜数量辗转变化的产物.人为因素在短期内对区域沙漠化的影响更为显著,甚至决定着沙漠化的演变方向.

Quantitative Analysis of Driving Forces to Land Desertification in Maqu Plateau During 1964-2014

Objective] The objective of this study was to analyze the driving forces of land desertification in Maqu plateau in order to provide basis and reference for ecological restoration of land degradation in the upper reaches of the Yellow River. Methods] Land desertification information was elicited from multi-phase remote sensing data, and the driving forces data were collected from Maqu meteorological stations during 1964-2014 and social-economic statistical yearbook of Maqu County Gansu Province. Principal component analysis(PCA) was used. Results] During 1964-2014, both natural and human factors contributed to the variation of land desertification area, their joint contribution was 57.18%. Driving factors of land desertification in Maqu Plateau varied in different stage during 1964-2014. The expansion of desertification land area in 1964-1980 was induced both by human and natural factors, but human factors played a dominant role with a contribution rate of 47.66%. The expansion of land desertification area in 1981-1997 was caused by the interaction of natural and human factors. The contribution rate of human factor and natural factor was 42.75%. During 1998-2014, the area of desertification land decreased by human factors. The contribution rate was 44.97%. Conclusion] The development of land desertification in Maqu plateau was the result of mutual interaction between fragile alpine ecosystem and the intervention of human activities. For human activities, population and livestock are important driving factors. And eventually, human factors are more important and might determine whether progress or retrogress evolution will happen in a short term.