1992-2015年中亚五国LUCC特征及耕地驱动力研究

The land-use and land-cover change characteristics and driving forces of cultivated land in Central Asian countries from 1992 to 2015

  • 摘要: 中亚五国地处亚欧大陆的中心地带,是“一带一路”全球发展战略中重要的沿线节点之一。借助GIS空间统计分析方法,以欧洲太空局气候变化项目全球土地覆盖数据为基础,利用土地利用程度、动态度和转移矩阵对中亚五国1992-2015年土地利用/覆盖变化(LUCC)特征进行分析,并运用地理探测器对耕地驱动力进行深入研究。结果表明:1)1992-2015年,中亚五国的土地利用格局总体上表现为耕地和城镇用地持续增加,林地、草地和水域呈减少的趋势。耕地的增加主要来自林地(7.88万km2)和草地(5.27万km2)的转入,城镇用地的增加主要来自耕地(0.50万km2)的转入,耕地是仅次于城镇用地增速较快、变化最为显著的土地利用类型;城镇用地在各国均呈现增加的趋势,耕地除乌兹别克斯坦之外,在其他4国均呈现增加的趋势。2)1992-2015年中亚五国土地利用程度总体呈缓慢上升趋势(土地利用程度综合指数从1992年的193.34增加到2015年的197.41),即土地利用处于发展阶段;土地利用程度为耕地> 林地> 草地> 未利用地> 水域> 城镇用地。3)地理探测器对耕地变化驱动因素的分析结果表明,自然因素中年平均降水量对耕地变化的作用较为显著,但在短时间内社会和农业因素发挥决定性的作用;因子探测表明人口总数(0.882)和农村人口(0.881)对耕地扩张的影响力最大,其次为粮食单产(0.746);交互探测表明各因子交互作用均为互相增强,其中,农村人口与粮食单产的叠加作用对耕地扩张的解释力度最大(0.972),影响耕地扩张的主要因素可归纳为人口增长和粮食单产提高。本研究可为中亚五国土地利用格局演变、区域土地利用规划和土地资源可持续利用提供决策支持。

     

    Abstract: Five countries located in the center of Eurasian continent (i.e., Central Asian countries) are important nodes along the Belt and Road Initiative, a global development strategy launched by China. The Central Asian countries' land-use and land-cover change (LUCC) characteristics from 1992 to 2015 were analyzed. The European Space Agency Climate Change Initiative global land cover data were used to determine the land-use degree, dynamic attitude, and transfer matrix by geographic information system (GIS) spatial analysis, and the driving force of cultivated land was explored using geographical detectors. The results showed that in the Central Asian countries, the area of cultivated and urban lands continuously increased, and that of forests, grasslands, and water areas decreased. Forests (7.88×104 km2) and grasslands (5.27×104 km2) were converted into cultivated land, and cultivated land (0.50×104 km2) was converted into urban areas. The transfer between land-use types was country-specific (e.g., cultivated land was created from forests and grasslands in Kazakhstan, Kyrgyzstan, and Tajikistan and from unused land in Turkmenistan; cultivated land became urban areas in Uzbekistan) and closely associated with human activities. Urban land had the highest growth rate in all countries, followed by cultivated land (except in Uzbekistan), and cultivated land was the most variable land-use type. The land-use degree slowly increased (comprehensive index of land use degree was 193.34 in 1992, 197.41 in 2015), indicating that land-use was in the development stage. Land-use types ranked as follows (by land-use degree): cultivated lands > forests > grasslands > unused lands > water areas > urban lands. The driving forces for cultivated land changes were analyzed using geographical detectors and showed that the annual average precipitation had a significant effect. Social and agricultural factors also played a decisive role in the short term. The total population and rural population had the greatest influence on cultivated land expansion, followed by the per unit area grain yield. Interactive detection showed that interactions between factors were mutually reinforcing. In particular, super-positioning rural population and crop production index explained cultivated land expansion. The primary factors affecting cultivated land expansion were population growth and agricultural production improvement. These results are useful for planning sustainable land use in Central Asian countries.

     

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