基于1990—2020年土地利用变化的西秦岭生境质量时空演变研究

Spatial and Temporal Evolution of Habitat Quality in the West Qinling Mountains Based on Land Use Change from 1990 to 2020

为进一步了解西秦岭区域生境质量状况、空间分布特征及其与土地利用类型变化之间的关系,以期解决该区域生境质量退化、生态系统受损、空间格局失衡、自然资源开发利用不合理等国土空间问题。本研究借助InVEST,利用生境质量模型、土地利用程度指数、双变量空间自相关等方法,以西秦岭三县区秦州区、康县、碌曲县1990—2020年土地利用数据为基础,对西秦岭近30 a的生境质量进行模拟评价。结果表明:(1)西秦岭东北部耕地面积降幅明显;南部和西部以草地和未利用地减少为主,其他土地利用类型面积增加;(2)西秦岭东北部、南部生境主要变化是由较高向高等级生境过渡,而中、较低等级生境向低等级生境过渡;西部主要是由较高向中等级生境变化,较低向低等级转化的过程,整体生境质量处于中等偏上水平;(3)西秦岭东北部、南部生境质量与土地利用程度整体呈负相关,相关程度有减弱的趋势;西部土地利用程度与生境质量呈正相关,且空间上存在集聚现象,空间集聚性先增强后减弱。(4)30 a来,西秦岭生境退化度一直为上升趋势,空间分布总体表现为东北部、东部及南部高,西部和西北部低。对西秦岭近30 a的生境质量进行模拟评价,为西秦岭生境质量提高、土地资源保护、区域土地利用方向等方面提供科学参考。

The aims is to further understand the status of habitat quality,spatial distribution characteristics and their relationship with land-use type changes in the western Qinling region,with a view to solving the territorial spatial problems such as degradation of habitat quality,damage to ecosystems,imbalance of spatial patterns,and irrational exploitation and utilization of natural resources in the region.In this study,with the help of InVEST,the habitat quality model,land use degree index,and bivariate spatial autocorrelation were used to simulate and evaluate the habitat quality of West Qinling in the past 30 years based on the land use data of Qinzhou District,Kang County,and Luqu County in West Qinling from 1990 to 2020.The results showed that:(1)the area of cultivated land in the northeast of West Qinling decreased significantly;in the south and west,the decrease of land was dominated by the grassland and unutilized land,and the area of other land-use types increased;(2)the main change of habitats in the northeast and south of West Qinling was the transition from higher to higher grade habitats,while the middle and lower grade habitats were transitioning to lower grade habitats;in the west,it was mainly a process of changing from higher to medium grade habitats and lower to lower grade habitats,and the overall habitat quality was in the middle to upper level;(3)the habitat quality in the northeast and south of West Qinling was negatively correlated with the degree of land use,and the degree of correlation had a tendency to weaken;the degree of land use in the west was positively correlated with the quality of habitats and there was a phenomenon of spatial agglomeration,with spatial agglomeration increasing and then decreasing.(4)Over the past 30 years,the degree of habitat degradation in West Qinling had been on an upward trend,and the spatial distribution was generally high in the northeast,east and south,and low in the west and northwest.The simulation and evaluation of the habitat quality of West Qinling in the past 30 years can provide scientific references for the improvement of the habitat quality of West Qinling,the protection of land resources,and the direction of regional land use.