1990—2015年武汉市土地利用碳排放格局研究

Study on spatio-temporal change of land use carbon emission pattern in Wuhan from 1990 to 2015

土地利用变化引起的碳排放增加,是全球碳排放量增加的重要原因,土地利用不合理会影响区域碳平衡。利用1990—2015年遥感影像数据和能耗数据,通过碳排放模型构建、碳排放效应测算、土地利用碳排放动态度和碳排放贡献率等方法,剖析了武汉市土地利用碳排放时空变化。结果表明:(1)武汉市碳排放量逐年增加,研究期内增加了91.02%,年均增长率为3.64%。建设用地是最大碳源,水域和林地是主要碳汇,建设用地的碳排放量是决定土地利用净碳排放量的主导因素。(2)单位国内生产总值的碳排放强度波动下降,人均碳排放强度稳定上升。(3)碳排放强度较大的地区主要集中在城市中心的建城区,远郊区林地集中的地区碳排放强度较小。武汉市“碳源”增强区以市中心呈现典型的圆形分布,而“碳汇”增强区零星分布在公园建设、退耕还林和退建还林区。(4)建设用地对区域碳排放量变化的碳排放贡献率高达99.75%,是区域碳排放的主要贡献因子。

The increase of carbon emission caused by land use change is an important reason for the increase of global carbon emission,and unreasonable land use can affect the regional carbon balance.In order to analyze land use change and the carbon emission effect of Wuhan,remote sensing image from 1990 to 2015 was used to reveal land use change pattern and its influence on carbon emission effect through the methods of carbon emission model,estimation of carbon emission effect,land-use carbon emission dynamics and carbon emission contribution rate.The results show that the carbon emission of the land use in Wuhan was increased by 91.02%,with an average annual growth rate of 3.64%.The construction land was the largest carbon source,followed by the cultivated land,water area and forest land were the main carbon sink,and the carbon emission of construction land was the dominant factor to determine the net carbon emission of land use.The fluctuation of carbon emission intensity per unit of GDP decreased,while the per capita carbon emission intensity increased steadily.The areas with high carbon emission intensity were mainly concentrated in the urban center of the city,while the areas with high forest land in the outer suburbs had low carbon emission intensity.The“carbon source”enhanced area in Wuhan showed a typical circular distribution in the center of the city,while the“carbon sink”enhanced area was scattered in the area of park construction,conversion of cropland to forest and conversion cropland to forest.The contribution rate of construction land to regional carbon emission was 99.75%,which was the main contribution factor of regional carbon emission.