基于土地利用变化的京津冀生境质量时空演变

Spatio-temporal variability of habitat quality in Beijing-Tianjin-Hebei Area based on land use change

土地利用变化是全球变化的核心内容,评估土地利用变化引起的生境质量时空分异性是区域生态规划的基础,能为土地利用规划和土地管理政策制定提供科学依据.本文在分析京津冀2000—2010年土地利用变化的基础上,以In VEST模型对生境质量进行总体评估,并基于流域划分,借助剖面线和空间自相关深入分析了生境质量格局时空分异性.结果表明:2000—2010年,研究区主要土地利用变化类型为:耕地转为建设用地、林地和草地间的相互转换及水体转为耕地,这导致景观结构异质性的减弱和破碎度的提升.两时期生境质量格局整体表现为东南部和南部较低、北部和西部较高.其中,东南部和南部2010年生境质量明显下降,发生了一定生境退化乃至丧失现象.各流域生境质量具有明显分段特征,较多样点在2010年出现不同程度退化,但也有部分有所改善.该区生境质量格局空间分布集聚性有所增强.2000年"高高"型生境质量流域空间聚集区为滦河流域和白河流域上游地区,"低低"型聚集区集中在永定河中下游和潮白河流域部分地区.2010年"高高"型和"低低"型空间聚集区在原有基础上各自向西南方向有所扩展.

Land use change is the core content of global change. To achieve sustainable land use planning,it is necessary to evaluate the habitat quality pattern and its spatio-temporal variation resulted from land use change,which can provide basis for the formulation of land management policy. Based on the analysis of land use change from 2000 to 2010,this study investigated the spatiotemporal variation of habitat quality pattern of Beijing-Tianjin-Hebei Area. We used the watershed profile sampling points and spatial autocorrelation analysis based on watershed subdivision. The results showed that the main land use change types from 2000 to 2010 in this area included the transition from cultivated land to construction land,the transition between forest and grassland,and the transition from water bodies to cultivated land. This land use / cover change process led to the decrease of heterogeneity of landscape structure and increase of fragmentation. The overall spatial pattern of habitat quality was that southeast and south areas were relatively lower,while north and west areas were relatively higher. The analysis based on watershed profile showed that the habitat quality of each watershed presented significant difference in each part. Habitat quality of most sampling points degraded in a way,while some improved compared with 2000. In general,the habitat quality of the bottom part of Luanhe River basin,the medium part of Bai-Chaobai-Chaobaixin River basin,the medium and the bottom part of Yongding River basin and medium part of Laozhang-FudongpaiBeipai River basin were poor and volatile,while other parts were relatively good. There was a decreasing agglomeration characteristic of distribution of habitat quality in Beijing-Tianjin-Hebei Area under the disturbance of human activities. Areas of high habitat quality in 2000 were mainly located in Luanhe River basin and top part of Baihe basin. Areas of low habitat quality were mainly located in medium and bottom part of Yongding River basin and some parts of Chaobai River basin. However,the areas of high habitat quality and areas with low habitat quality of 2010 had both expanded towards southwest.