多情景下张家口市土地利用变化及碳储量分析

Analysis and Multi-scenario Prediction of Carbon Storage in Zhangjiakou City under Land Use Structure Change

土地利用改变促进生态系统碳储量变化,进而对全球气候产生影响,研究土地利用变化对碳储量的影响,对区域生态系统和实现经济可持续发展具有重要意义。该研究以张家口市为例,基于2000年、2010年和2020年土地利用数据,结合PLUS模型和InVEST模型分析土地利用变化与碳储量的关系并对未来不同情景下的碳储量进行评估。结果表明:(1)张家口市土地利用类型以耕地和草地为主,占该地区总面积约71%。20年间,耕地和草地面积呈下降趋势,林地、建设用地面积呈现增长态势,其主要转换方向为耕地转为建设用地。(2)2030年,自然发展情景下,耕地、林地、水域均有所下降,草地、建设用地和未利用地有所增长;生态保护情景下,林地和草地相较自然发展有所增加,其余地类均有不同程度的减少;耕地保护情景下,耕地面积相较于自然发展情景增加约1.11 km^(2)。(3)过去20年间,该区域碳储量先上升后下降,但总体碳储量依然呈现下降趋势,年均下降0.19×10^(6)t;2030年自然发展情景下,碳储量为766.43×10^(6)t;耕地保护情景下,碳储量为767.28×10^(6)t;生态保护情景下,碳储量为768.5×10^(6)t。耕地保护碳储量介于自然发展和生态保护之间,因此张家口市在未来发展中应实行耕地优先发展前提下采取一定生态保护措施,以减缓碳储量下降速率。

Land use changes promote variations in ecosystem carbon storage,thereby influencing global climate.Investigat⁃ing the impact of land use changes on carbon storage is crucial for regional ecosystem management and achieving economic sustainability.Taking Zhangjiakou City,Hebei Province as a case study,this research utilizes land use data from 2000,2010,and 2020,coupled with the PLUS and InVEST models,to analyze the relationship between land use changes and carbon storage.Furthermore,it evaluates carbon storage under different future scenarios.The results showed that the land use types were mainly cropland and grassland,accounting for about 71%of the total area.Over the past 20 years,there has been a declining trend in the area of cropland and grassland,while the area of forest land and cropland has showed an increasing trend,and the main direction of conversion was cultivated land to construction land.In 2030,under the natural development scenario,there will be a decrease in the areas of cropland,forestland,and water bodies,while grassland,construction land,and unused land will experience growth.In the ecological protection scenario,compared to natural development,there will be an increase in forestland and grassland,with other land categories experiencing varying degrees of reduction.Under the crop⁃land protection scenario,the area of cropland is projected to increase by approximately 1.11 km^(2) compared to the natural de⁃velopment scenario.Over the past 20 years,the carbon storage in this region increased first and then decreased,but the overall carbon storage showed a downward trend,with an average annual decrease of 0.19×10^(6) t.Under the natural develop⁃ment scenario in 2030,carbon storage is 766.43×10^(6) t;under the cropland protection scenario,the carbon storage is 767.28×10^(6) t,under the ecological protection scenario,the carbon storage is 768.5×10^(6) t.Cropland protection falls between natu⁃ral development and ecological protection in terms of carbon storage,suggesting that the City should prioritize crop⁃land development while implementing certain ecological protection measures to mitigate the rate of decline in carbon storage in future development.