黑河中游土地利用/覆盖变化及主导因素驱动力

为探讨人文因素在黑河中游绿洲土地利用/覆盖变化过程中的驱动作用,以张掖市甘州区为例,首先分析了在人文因素作用下,研究区2002-2011年各土地利用类型面积变化的速度和幅度以及土地利用/覆盖程度综合指数;其次,在明确各类型土地利用变化趋势的基础上,建立人文因素指标体系,模拟人文因素与土地利用/覆盖变化之间的多元线性关系;最后通过灰色关联分析,提取影响不同用地类型的关键人文因素指标。分析结果表明:2002-2011年甘州区土地利用/覆盖整体结构中,建设用地加速扩张,农用地资源减少,土地利用结构非农化趋势明显;人文因素对甘州区主要用地类型的LUCC(land use/cover change)过程的驱动作用达到90%以上,且在不同类型用地变化过程中各人文因素贡献率不同;采用灰色关联分析法得出,文章评价指标体系中,农业人口数量下降,农业科技人员数量上升以及电机井总数量持续增加分别是2002-2011年甘州区城乡建设用地、交通水利建设用地、耕地变化的主导人文因素指标。

Land use/cover changes and main-factor driving forcein Heihe middle reaches

Abstract: Land-Use and Land-Cover Change (LUCC) is a core program supported by the International Geosphere-Biosphere Program (IGBP) and the International Human Dimensions Program on Global Environmental Change (IHDP). Analyzing anthropogenic influence impacting on LUCC is one of key frontier domains supported by IGBP and IHDP, which requires differentiating and analyzing impact by anthropogenic factors on LUCC, and tightly combining LUCC with social, political, and economic issues. LUCC reflects the most direct and most close relationship between humanity and nature in the interaction. It is a process of adjusting all kinds of land use constantly in order to meet the need of social and economic development, and give expression to the development tendency that humans utilize land to be working and living.Due to the effect of the restriction of the special natural conditions, resources and the environment system in a continental river basin in an arid zone are especially affected by anthropogenic influences. Some scholars pointed out that, if the effective strength of human activities exceeds 37%, the river surface runoff process shits from its natural state to giving priority to an anthropogenic disturbance, Therefore, affecting the middle and lower reaches of the oasis area size would directly impact on the process of the middle reaches of land -use and land-cover change. In order to understand the current problem of the land, we needed to identify the key human influencing factors, discuss its regulatory mechanism, and evaluate its effect on land -use and land-cover change, on basis of which we sought countermeasures to solve the problem. There are many attempts at related research on an anthropogenic driving effect on land -use and land-cover change by quantitative analysis. However, the anthropogenic influence during the course of basin scale land change has not been extensively researched.In order to investigate the driving effect by anthropogenic influence on land use and land cover change in the Heihe Middle Reaches, this paper took Ganzhou District as an example. First, this article analyzed the velocity and amplitude of various land use types and a comprehensive index of LUCC in the study area under anthropogenic influence from the year 2002 to 2011. Secondly, based on specifying the trend of various types of land use change, this article established a humanistic factors index system, and simulated multiple linear relationships between humanities factors and LUCC. Finally, it extracted key humanity factors that affected different land use types through Grey Relational Analysis. The results of the analysis were as follows: 1) In the overall structure of land use/cover of the Ganzhou area from 2002 to 2011, construction land expanded at an accelerating pace, agricultural land resources were being reduced, and the non-agricultural trend of land use structure was evident. 2) Population, poverty and wealth conditions, social economy, technology, policy and cultural concepts resulted in resultant forces to promote regional land use/cover change. The contribution rates of different anthropogenic influences were different in the process of land use change of different types. 3) Using a grey correlation analysis method in the evaluation index system, we found that the agricultural population declined, agricultural science and technology personnel rose, and the amount of motor-pumped well electricity continuing to grow were the dominant cultural factors index respectively to the change of urban and rural construction land, transportation and water conservancy, construction land and cultivated land in 2002-2011.