石羊河流域土地利用变化及其对乡村恢复力的影响 ——以流域典型乡镇为例

摘要

西北干旱区受内陆干旱气候影响，生态环境脆弱，经济社会发展受阻，人地矛盾突出，严重影响了区域自然生态健康和区域可持续发展。石羊河流域地处西北干旱区，具有人口密集、经济发展水平较高、水资源开发利用程度高等特征。上世纪80年代以来，受到资源高强度开发、耕地无序扩张等人类活动的影响，人地矛盾进一步激化。本研究基于社会-生态系统分析框架和恢复力理论，以石羊河流域不同区段典型乡镇为研究对象，综合利用自然环境遥感数据、土地利用数据和社会经济数据，运用恢复力评价指标体系构建、典型相关分析、Markov模型、OWA等方法对各乡镇土地利用变化与乡村恢复力时空演变进行客观系统分析，并进一步研究土地利用变化对乡村恢复力的影响关系，探讨土地利用变化历史、现状和未来情景下的乡村恢复力变化，旨在协调人地关系、缓解生态环境与社会经济发展矛盾、推进石羊河流域乃至干旱区内陆河流域人地系统可持续发展进程。主要研究结论如下：

（1）石羊河流域内不同区段乡村恢复力时空变化差异较大。从时间序列上来看，2000-2020年间，除高坝镇社会维度恢复力外，各乡镇各维度恢复力均呈现升高趋势，但乡镇之间相对变化幅度较大。从空间分布上看，各乡镇生态维度恢复力呈现出从上游到中游先降低后升高、从中游到下游逐渐降低到整体呈现出从上、下游到中游逐渐减小的空间分布特征；社会维度恢复力一直呈现为从上、下游向中游逐渐减小的空间分布特征；经济维度恢复力则与社会维度相反，呈现出中游较高，向上、下游逐渐减少的分布格局；乡村恢复力空间分布格局随时间推移逐渐均质化。

（2）不同时期各乡镇土地利用变化趋势特征各异。从各乡镇来看，东湖镇和哈溪镇的生态用地增长面积较大、增速较快，高坝镇的建设用地占比增加较快，黄花滩镇的耕地和建设用地增速较快，而苏武镇整体土地利用变化不大；整体看来，除黄花滩镇外，各乡镇耕地面积呈下降趋势，林、草地等生态用地呈上升趋势，未利用地面积不断减少，而建设用地面积逐渐增加。

（3）土地利用结构与乡村恢复力密切相关，不同土地利用类型对不同维度恢复力影响各异。其中，林地和草地等生态用地面积占比对生态维度恢复力具有较强的正向影响，土地垦殖率和建设用地占比则对经济维度恢复力影响较大，土地退化率（未利用地占比）对生态和经济维度恢复力都具有负面影响，各地类变化对社会维度恢复力均无明显影响方向。

（4）不同情景下未来土地利用变化趋势特征和恢复力时空变化特征各不相同。从土地利用情景看，其中基准发展情景基于2000-2020的土地利用转移变化趋势进行模拟，各乡镇未来土地利用变化趋势特征与2000-2020年相似；在社会经济增长情景下，建设用地的快速增长成为经济社会增长情景下土地利用变化的主要特征；而林、草地等生态用地面积增加和未利用地面积快速减少是生态保护情景下未来土地利用变化的基本特征。从三种不同恢复力情景来看，维持现状型和经济优先型下恢复力空间差异较大，而可持续增长情景下流域各区段恢复力空间分布较为均衡。

（5）未来土地利用变化与恢复力变化之间存在着显著的相关关系。其中，林地占比和草地占比与生态维度恢复力之间存在显著的正相关关系，耕地占比在与生态维度恢复力呈负相关关系；仅有建设用地占比与社会维度恢复力呈现明显的负相关关系；耕地占比和建设用地占比与经济维度恢复力呈现正向相关关系，而未利用地占比与经济维度恢复力呈负相关关系；林草地等生态用地占与乡村恢复力呈正向相关关系，生态保护仍是流域未来发展需要关注的重点。

关键词：社会-生态系统，乡村，土地利用，恢复力，石羊河流域

XIII

ABSTRACT

The northwest arid region is affected by the inland arid climate,the ecological environment is fragile,the economic and social development ishindered, and the contradiction between human and land is prominent, which seriously affects the regional natural ecological health and the sustainable development of the region. Shiyang River Basin is located in the arid area of northwest China,which has the characteristics of dense population,high level of economic development and high degree of water resources exploitation and utilization. Since the 1980s, under the influence of human activities such as high-intensity exploitation of resources and disorderly expansion of cultivated land,the contradiction between man and land in the basin has been furtherintensified, the natural environment has deteriorated, and economic and social development has been hindered. Based on the framework of socio-ecological system analysis and resilience theory,this study takes typical towns in different sections of Shiyang River Basin as the research objects. Natural environment remote sensing data and land use data and socioeconomic data such as data,restoring force construction of evaluation index system, canonical correlation analysis,Markov model, such as, OWA method was used to rural land use change and the resilience of space-time evolution analysis,and further study the effect of land use change on resilience, to explore the history, present situation and the future of the land use change situations of rural resilience. The aim is to coordinate man-land relationship,alleviate the contradiction between ecologicalenvironment and social and economic development, and promote the sustainable development process of man-land system in Shiyang River Basin and even the arid land inland river basin. The results can be summarized as follows:

(1) The temporal and spatial variation of rural resilience in different sections of Shiyang River Basin is great. From the perspective of time series, from 2000 to 2020,the resilience of all dimensions of towns showed an increasing trend, but the relative change range among towns was large. In terms of spatial distribution,the resilience of ecological dimension decreased first and then increased from the upper reaches to the middle reaches, gradually decreased from the middle reaches to the lower reaches, and gradually decreased from the upper and lower reaches to the middle reaches. Resilience of social dimension is gradually decreasing from upper and lower reaches to middle reaches. The resilience of economic dimension is opposite to that of socialdimension, showing a higher distribution pattern in the middle reaches and a gradually decreasing pattern in the upper and lower reaches. The spatial distribution pattern of rural resilience was gradually homogenized over time.

(2) The characteristics of land use change trend are different in different periods.From the perspective of each township,the area of ecological land in DonghuTown and Haxi Town increased larger andfaster, the proportion of construction land in Gaoba Town increased faster, the cultivated land and construction land in Huanghuatan Town increased faster, but the overall land use in Suwu Town changed little. In a whole word, except for Huanghuatan town,the area of cultivated land decreased,the ecological land such as forest and grassland increased, the unused land decreased, and the area of construction land increased.

(3) Land use structure is closely related to rural resilience,and different land use types have different effects on different dimensions of resilience. Among them, the dimension of woodland and grassland area of ecological resilience has strong positive influence, arable land,construction land proportion and accounted for the influence on the economic dimension of resilience is bigger, unused land ecological and economic dimensions of resilience has negative impact, around the class changes had no significant effect on social dimension restoring force direction.

(4) The characteristics of future land use change trend and spatiotemporal change of resilience are different under different scenarios. From the perspective of land use scenarios,the characteristics of future land use change under the baseline development scenario are similar to those in 2000-2020.The rapid growth of construction land has become the main feature of land use change under the socio-economic growth scenario. The increase of forest,grassland and other ecological land area and the rapid decrease of unused land area are the basic characteristics of future land use change under the ecological protection scenario. From the perspective of three resilience scenarios,the spatial difference of resilience is obvious under the maintenance status quo scenario and the economic priority scenario, while the spatial distribution of resilience is more balanced under the sustainable growth scenario.

(5)There is a significant correlation between future land use change and resilience change.Firstly, there was a significant positive correlation between the proportion of forestland and grassland and the resilience of ecological dimension,while the proportion of cultivated land was negatively correlated with the resilience of ecological dimension. Furthermore, only the proportion of construction land was negatively correlated with the resilience of social dimension. In addition, the proportion of cultivated land and construction land has a positive correlation with the economic dimension resilience,while the proportion of unused land has a negative correlation with the economic dimension resilience. In general, there is a positive correlation between the proportion of ecological land such as forestland and rural resilience,and ecological protection is still the focus of the future development of the river basin.

Keywords: social-ecological systems, rural area, resilience, land use, Shiyang River Basin