土地利用变化背景下植被大气PM_(2.5)去除能力动态评估

Dynamic Assessment of Atmospheric PM_(2.5)Removal Capacity of Vegetation in the Context of Land Use Change

为了加深对土地利用变化背景下植被大气净化功能的量化理解,回顾分析2000—2020年丽水市土地利用变化趋势,利用干沉降模型评估植被对PM_(2.5)去除能力的动态变化;利用地理加权回归模型分析植被对PM_(2.5)去除能力变化的主要驱动因素,并基于此利用PLUS模型在空间上预测未来不同管理情景下2030年土地利用格局及植被PM_(2.5)去除能力。结果表明,2000—2020年土地利用变化的主要类型是由社会经济因素所驱动的建设用地对林地的侵占;在城市化和大气污染治理的共同作用下,2020年丽水地区植被大气PM_(2.5)干沉降速率相比2000年下降了3.0%,干沉降通量由2000年的0.36 g/(m^(2)·a)下降至2020年的0.26 g/(m^(2)·a);自然环境因素对植被大气PM_(2.5)去除能力的空间分异规律解释能力最强;自然发展情景下,2030年植被大气PM_(2.5)去除能力相比2020年继续下降了1.6%,而生态保护情景则增加了1.3%。2000—2020年,丽水市的耕地、林地和草地面积呈缩减趋势,水域及建设用地面积有所扩张,主要受到社会经济因素的推动;植被大气PM_(2.5)干沉降去除能力不断下降,其空间分异主要与自然环境因素有关;在未来情景中,按照现有发展模式植被大气PM_(2.5)干沉降去除能力将继续下降,而生态发展情景下干沉降去除能力将有所提高。

To deepen the quantitative understanding of the air purification function of vegetation in the context of land use change,this study reviewed the trends of land use change in Lishui City from 2000 to 2020,assessed the dynamic changes of vegetation′s ability to remove PM_(2.5) by using a dry deposition model.Additionally,the study used a geographically weighted regression model to analyze the primary drivers of land use changes and utilized the PLUS model to spatially predict the land use patterns and vegetation PM_(2.5) removal capabilities under different management scenarios by 2030.The results showed that the primary type of land use change from 2000 to 2020 was the encroachment of construction land on forest areas driven by socio-economic factors;under the joint influence of urbanization and air pollution control,the dry deposition rate of atmospheric PM_(2.5) by vegetation in Lishui area decreased by 3.0% in 2020 compared to 2000,and the dry deposition flux decreased from 0.36 g/(m^(2)·a)in 2000 to 0.26 g/(m^(2)·a)in 2020;natural environmental factors had the strongest explanatory power for the spatial variation in the PM_(2.5) removal capacity of vegetation;under a natural development scenario,the PM_(2.5) removal capacity of vegetation by 2030 would continue to decline by 1.6% compared to 2020,while an ecological protection scenario would see an increase of 1.3%.In summary,from 2000 to 2020,the area of cultivated land,forest land and grassland in Lishui City showed a shrinking trend,and the area of water and construction land expanded,which was mainly driven by socio-economic factors;the dry deposition removal capacity of vegetation for atmospheric PM_(2.5) continued to decline,and its spatial differentiation was mainly related to natural environmental factors;in the future scenario,under the current development model,the dry deposition removal capacity of vegetation for atmospheric PM_(2.5) would continue to decline,while the dry deposition removal capacity would increase under the eco-development scenario.