生态脆弱区城市生态用地碳效应时空演变研究

Spatiotemporal Evolution of Carbon Effects of Urban Ecological Land in Ecologically Fragile Areas

【目的】研究城市生态用地变化及其碳排放的时空特征变化,为全面把握城市发展中碳排放变化趋势和城市间土地利用调整提供参考。【方法】通过榆林市5期土地利用遥感数据,采用碳排放模型、碳足迹压力模型、热点转移模型等方法,研究2000—2020年榆林市生态用地转移引起的碳排放效应及其空间特征。【结果】2000—2020年,榆林市生态用地净碳排放总体呈下降趋势,由2000年的637028 t减少到2020年的572875 t,碳足迹压力指数由4.3102下降至3.6683;碳排放风险指数由0.1491下降到0.1371。【结论】榆林市碳汇用地中心整体呈现向东南移动,碳源用地中心整体呈现向西北移动,榆林市县域碳源碳汇变化热点区域的图斑较为集中,而冷点地区变化的图斑相对分散。从空间尺度上看,榆林市的碳源和碳汇分布格局具有南部强碳源和北部强碳汇的特征,空间分布与碳净排放量一致。

[Purposes]The purpose of this paper is to study the changes of urban ecological land use and the temporal and spatial characteristics of carbon emissions,so as to provide reference for comprehensively grasping the changing trend of carbon emissions in urban development and the adjustment of land use between cities.[Methods]Based on the five-phase remote sensing data of land use in Yulin City,carbon emission model,carbon footprint pressure model and hot spot transfer model were used to study the carbon emission effect and its spatial characteristics caused by ecological land transfer in Yulin City from 2000 to 2020.[Findings]From 2000 to 2020,the net carbon emission of ecological land in Yulin City decreased from 637028 t in 2000 to 572875 t in 2020,the carbon footprint pressure index decreased from 4.3102 to 3.6683,and the carbon emission risk index decreased from 0.1491 to 0.1371.[Conclusions]The overall center of the carbon sink land in Yulin City is moving to the southeast,and the carbon source land center is moving to the northwest as a whole.The spots in the hot areas of carbon sources and carbon sinks in the county of Yulin City are more concentrated,while the spots in the cold spots are relatively scattered.From the spatial scale,the distribution pattern of carbon sources and carbon sinks in Yulin City has the characteristics of strong carbon sources in the south and strong carbon sinks in the north,and the spatial distribution is consistent with the net carbon emissions.