湘西土家族苗族自治州不同海拔梯度 景观格局时空变化特征

spatial and Temporal variation characteristics of Landscape pattern at Different Altitude Gradients in xiangxi prefecture

摘要:

探究区域尺度不同海拔梯度下的景观格局变化特征,对维护区域可持续发展具有重要意义 。本研究以湘西土家 族苗族自治州(以下简称湘西州)为研究区,基于 30m分辨率的 CLCD土地覆盖数据集,利用 ArcGIS和 Fragstats 软件进 行统计处理,对比分析 2000~2020年不同海拔梯度景观格局的动态变化特征,结果表明:①研究区土地利用类型的变化特 征主要是农业用地和森林的相互转换,其中森林为研究区内的优势景观,海拔越高优势度越大,且面积保持逐年增长,主要 得益于植树造林、封山育林等林业工程取得良好成效,其次是农业用地,其面积逐年减少,是建筑用地的主要来源;②对比 研究区各景观指数近20年来的变化趋势,研究区内景观破碎程度降低,由小斑块向大斑块聚集,反映出湘西州城镇空间结 构不断优化,土地利用与开发逐渐规模化;高海拔山地地区也能因地制宜,在不破坏生态环境的前提下发展药材种植经济 ; ③在湘西州划分的 4个海拔梯度中, T1~T3梯度的土地利用与景观格局时空变化特征较为接近, T4梯度才出现了明显差 异 。说明在以山地地形为主体的湘西州,海拔 1500m左右是生态环境发生变化的重要分界线 。通过剖析湘西州的景观空 间结构及其影响因子,可为湘西州的景观规划发展以及生态资源的保护、管理和合理开发提供科学支持和规划建议。

Abstract:

It is great signiFicance to explore the characteristics oFlandscape pattern changes at diFFerent altitudes at re- gional scales For maintaining regional sustainable development. In this study, xiangxi preFecture was taKen as the research area . Based on the cLcDland cover data set with 30m resolution, ArcGIs and Fragstats soFtware were used For statistical processing, and the dynamic changes oFlandscape patterns at diFFerent altitude gradients From 2000 to 2020 were com- pared and analyzed. The results showed that :①The change characteristics oFland use types in the study area were mainly the mutual conversion oFagricultural land and Forest. Among them, Forest is the dominant landscape in the study area . The higher the altitude was , the greater the dominance was , and the area Kept increasing year by year . Followed by agricultur- al land, its area decreased year by year , was the main source oFconstruction land ;②comparing the change trend oFeachlandscape index in the study area in the past 20 years , the degree oFlandscape Fragmentation in the study area had de- creased, and it had gathered From small patches to large patches , reFlecting the continuous optimization oFurban spatial structure in xiangxi preFecture and the gradual scale oFland use and development. High— altitude mountainous areas could also adapt to local conditions and develop medicinal planting economy without destroying the ecological environment. ③In the Four elevation gradients divided by xiangxi preFecture , the temporal and spatial variation characteristics oFland use and landscape pattern in T1~T3gradients were close , and there was a signiFicant diFFerence in T4gradients . It shows that in xiangxi preFecture , which is dominated by mountainous terrain, the altitude oFabout 1500m is an important dividing line For the change oFecological environment. By analyzing the landscape spatial structure and its inFluencing Factors in xiangxi , it can provide scientiFic support and planning suggestions For the landscape planning and development oFxiangxi and the protection, management and rational development oFecological resources .