Evaluation Of The Industrial Heat Sources Activities Over Jin-Jin-Ji Region And Their Impact On The Air Pollution Based On Satellite Data

In recent decades,the rapid development of heavy industries in the Jing-Jin-Ji region brought series of problems caused by industrial expansion.These problems threaten the sustainable development of social economy,and increase the pressure on regional resource and environment.Therefore,timely mastering the geographical distribution and dynamic changes of heavy industrial enterprises in Jing-Jin-Ji region is of great significance for industrial structure adjustment,sustainable development and ecological environmental protection of heavy industries.In this study,VIIRS 375m data,MODIS land surface temperature(LST)products,ground-based measurements from China environmental monitoring stations and Hebei county monitoring station were used for analyzing the situations of heavy industries in the Jing-Jin-Ji region from 2012 to 2017.Firstly,NDVI,K-Means++,visual interpretation and spatial filtering were adopted for determining the specific locations and types of heavy industrial enterprises.And then,based on the VIIRS 375m thermal anomaly spots and MODIS LST data,both the qualitative and quantitative analysis were made for heavy industrial actives.Lastly,we tried to investigate the impact of heavy industrial actives on the regional air pollution by using MODIS LST data and ground-based monitors of air quality factors.The main work and results of this paper are as follows.(1)Based on the VIIRS 375m thermal anomalies,K-Means++method,visual interpretation algorithms and spatial filtering were employed to identify heavy industry targets in the Jing-Jin-Ji region.All the identified heavy industrial enterprises were grouped into four types.The relationship between heavy industrial actives of these four heavy industrial types and their monthly numbers of VIIRS 375m thermal anomalies was analyzed.The results show that the total number of the heavy industry factories over the Jing-Jin-Ji decreases 19.2%from 2012 to 2017.Numbers of heavy industry factories in the Steel,Chemical,Gas and Machinery manufacturing categories decline 14.2%,23.1%,-2.9%and 41.5%respectively.And the VIIRS 375m thermal anomalies can reflect the production and operation status of heavy industry enterprises.(2)Because several production sectors of heavy industry factories emit a large amount of heat to the outside environment,the economic activities of heavy industry factories can be analyzed by establishing time series of heat island intensity index calculated by MODIS LST data.Our results indicate that in a certain period,the heavy industry enterprises are in the normal production state when the heat island intensity index exceeds the seasonal background value.When the gap between the heat island intensity value and the seasonal background value is narrowed,or when the heat island intensity value is lower than the seasonal background value,it reflects that the heavy industry enterprises have reduced the production level or even stopped production.(3)The statistical analysis of MODIS LST data of heavy industry factories and nearby environmental air quality automatic monitoring station data shows that LST data has certain positive correlations with the various pollutant concentrations.pollutant concentrations of SO2 show the highest relevance with MODIS LST data,and R2 reaches up to 0.779.R2 values between MODIS LST data and mass concentrations of NO2,CO,O3,PM2.5 and PM10 are 0.606,0.428,0.296,0.306 and 0.295 respectively.Therefore,it is practicable,to some extent,for evaluating the surrounding environmental pollution levels by monitoring the LST levels of heavy industry factories,which can provide some help for government departments to supervise heavy industrial enterprises.