武汉市湖泊水域利用转变及其碳排放影响

考虑到湖泊水域面积与土地面积的相互变迁进程,以及土地利用变化已成为仅次于化石能源燃烧的第二大温室气体排放源的客观现实,首次尝试分析特定区域湖泊水域的变化以及间接产生的碳源碳汇影响。根据2005、2010和2015年遥感影像获取武汉市湖泊水域利用转变的数据,采用国际通用的土地碳排放测算模型,评估武汉市湖泊水域转变为4类用地产生的碳排放量及碳强度变化情况。研究显示:(1)2005～2015年武汉市湖泊水域面积整体减少超10 km~2,且2010年后呈现加速萎缩趋势, 2010～2015年的减少值约为2005～2010年减少值的2.04倍;(2)虽然部分耕地、林地和草地转化为湖泊导致湖泊水域的增加,但湖泊大面积转变为建设用地导致水域面积的显著较少;(3)从碳排放总量来看,变动面积区域内呈碳源区,后5年碳源值是前5年的1.45倍;前后5年湖泊水域变化的碳排放强度分别为0.03和0.04 t/km~2,碳排放强度明显增加。针对武汉市湖泊水域利用的现实状况,提出把"山水林田湖草"放到统一的管理机制中进行考虑、规范土地资源利用、限制建设用地过度扩张等措施。

Utilization Change of Lake and Its Carbon Emission in Wuhan City

Considering the dynamic change of lake and land area, and the fact that land-use change has become the second largest greenhouse gas emission source after fossil energy combustion, this paper originally analyze the changes of the area of lake in a specific region and its indirect carbon effects. Based on the data obtained from remote sensing images in 2005, 2010 and 2015, the carbon emissions and carbon intensity changes from lake to four types of land in Wuhan city were assessed by the recognized model measuring carbon emission. The results show that: (1) From 2005 to 2015, the lake area in Wuhan decreased by more than 10 km2, and this trend accelerated after 2010. the reduction in 2010-2015 was about 2.04 times that in 2005-2010；(2)Although the conversion of some cultivated land, woodland and grassland into lakes leads to an increase in lake waters, the conversion of large areas of lakes into construction land directly results in significantly less water area;；(3)From the perspective of total carbon emission, the water conversion area was carbon source, and the carbon emission in the last five years was 1.46 times of that in the first five years. The carbon emission intensity was 0.03 t/km² from 2005-2010 and 0.04 t/km² from 2010-2015. The carbon emission intensity has increased obviously. In view of the situation of lake use in Wuhan, measures are put forward, such as “putting landscape, forestry, fields, lakes and grasses” into a unified management mechanism, standardizing the utilization of land resources, and restricting the excessive expansion of construction land.