基于DEM的山区冬季燃煤污染物排放遥感测算——以北京市门头沟区为例

Estimation of coal-burning contamination emissions in mountain areas during winter season based on DEM: A case study of Mentougou, Beijing

选择山地面积占98.5%的北京市门头沟区作为研究区,利用资源三号(ZY-3)三线阵前、后视影像构建立体模型,提取数字高程模型(Digital Elevation Model,DEM).由高分二号影像,基于CART(Classification and Regression Tree)决策树的面向对象方法对居住房屋进行提取,获取空间分布与面积,并结合采暖面积、采暖季燃煤量等抽样调研数据确定的深、浅山区(海拔>300m为深山区,海拔<300m为浅山区)燃煤系数,建立燃煤量估算模型.进一步,基于文献调研法获取型煤排放因子,测算燃煤产生的PM10、PM2.5、NOx、SO2、CO的排放量.结果表明:借助遥感技术,基于DEM可对山区燃煤污染物排放量进行快速有效测算.地形对冬季燃煤量有显著影响,深山区燃煤系数分别为12.5kg/m2,浅山区为9.375kg/m2.2017年门头沟使用型煤取暖的房屋面积为5.68km2,冬季燃煤总量为6.52万t,山区各镇大气污染物排放量差别较大.

At present,the research on coal pollution emissions has focused on plain areas and has largely ignored mountainous areas.In this paper the mountainous region of Mentougou in Beijing was selected as the research study area as it has 98.5%of its area covered by mountains.A stereo model was constructed to extract a DEM(Digital Elevation Model)using forward-looking and backward-looking ZY-3 images.Classification and a regression tree model(CART)combined with an object-oriented method were used to extract residential areas from GF-2 remote sensing images.Imagery interpretation along with statistical records of the residential areas were used to derive a coefficient of burning coal in a mountainous area.A statistical model was then developed to estimate coal consumption in a mountain area.A literature search helped us to determine emission factors and to estimate the specific emissions of PM10,PM2.5,NOx,SO2,and CO.With the help of remote sensing and a DEM this study demonstrates that the emission of coal-fired pollutants in mountainous areas can be measured efficiently and effectively.Terrain had a significant effect on coal combustion in winter.The derived coefficient of burning in a deep mountainous area was 12.5kg/m2 while the shallow mountain area exhibited a value of 9.375kg/m2.In the mountain region of Mentougou in 2017 the area of coal-fired residential buildings was 5.68km2.The derived coefficient of burning in a deep mountainous area was 12.5kg/m2 while the Shallow mountain area exhibited a value of 9.375kg/m2.The coal consumption was 0.0652 million tons in the winter,but the emission of air pollutants varied greatly among the towns in the mountainous areas.