益阳市“三区空间”时空变化特征及其生态环境效应研究

Spatio-Temporal Change Characteristics and Its Ecological Environmental Effects of the “Three-Function Spaces” in Yiyang City

揭示国土空间变化的规律及其生态响应是开展国土空间开发与保护的重要基础。以长江经济带重要节点城市益阳市为例,基于2000,2010和2018年三期土地利用数据构建“三区空间”(城镇空间、农业空间和生态空间)分类体系,采用转移矩阵、生态环境质量指数和生态贡献率方法分析“三区空间”时空变化特征及其生态环境效应。研究结果表明:(1)在研究期内益阳市生态空间波动减少,城镇空间持续增加,呈“核心+点状”空间扩张特征,农业空间和城镇空间补偿生态空间的趋势增加;(2)生态环境指数呈“L”型变化特征,与“三区空间”的数量变化特征基本一致,生态环境质量呈现由西南的山地、丘岗向东北平湖梯次递减的空间分异特征;(3)耕地转化成林地、水域转化为未利用地是生态环境质量改善的主导因素,生态环境退化的主导因素是林地转建设用地和林地转耕地,次要因素是耕地转建设用地。

Revealing the law of territorial space change and its ecological response is an important basis for the development and protection of territorial space.Taking Yiyang,which is an important node city of the Yangtze River Economic Belt,as an example,a classification system for “three-function spaces”(urban space,agricultural space,and ecological space) was constructed based on the remote sensing data of land use from three periods in 2000,2010,and 2018.The spatial and temporal changes and ecological environmental effects of “three-function spaces” were analyzed by spatial transformation matrix,ecological environment quality index,and ecological contribution rate methods.The research results are presented as follows.(1) During the studied period,the ecological space of Yiyang decreases,while the urban space continues to increase,showing a “core + point” spatial expansion feature.The trend of the ecological space compensated by the agricultural and urban spaces is increasing.(2) The change of ecological environment index is like an “L”,which is basically consistent with the variation characteristics of the “three-function spaces”.The eco-environment index shows a spatial differentiation characteristic of decreasing from mountainous and hilly areas in the southwest to flat lakes in the northeast.(3) Conversions of cultivation into forest and water into unused-land are the main factors for improving ecological environment quality.The factors causing the decline of the eco-environment quality are conversions of forest into construction and forest into cultivation.The conversion of cultivation into construction is just behind them.