Study On Surface Temperature Change Of Oil Sand Mining Area In Alberta Province,Canada,1990-2019

In recent years,with the continuous development of global green mining,ecological environment monitoring and governance in mining areas has become the focus of scholars' research.The development of mineral resources makes the mining area face a series of serious ecological environment problems.Carrying out ecological environment monitoring in mining area is an important means of mine management and an important reference basis for ecological restoration and management of mining area.Land surface temperature is the key factor of surface energy and water balance.It is also the input parameter of remote sensing models such as surface flux,soil moisture,crop water shortage model and yield estimation.It is also an important indicator to monitor the dynamic changes of the earth's resources and environment.It also plays an irreplaceable role in the process of energy exchange between the surface and the atmosphere.Land surface temperature inversion is widely used in regional hydrology,ecology,environmental monitoring and other research fields.Remote sensing technology has incomparable advantages in macro ecological environment monitoring Combination of Landsat-8 OLI/TIRS and Landsat-5 TM remote sensing images from 1990 to 2019 combined with modis-mod11 Taking the oil sand mining area in Alberta province of Canada as the research object,this paper selects the land surface temperature,which is an important parameter reflecting the ecological environment change of the mining area,through the data cutting,mosaic,radiation calibration,atmospheric correction,geometric correction and other preprocessing,and then based on envi software platform,the atmospheric correction method is used to retrieve the surface temperature of the mining area.Based on the Landsat-5 TM and Landsat-8 OLI/TIRS remote sensing data,the land cover information extraction and mapping were carried out,and the temporal and spatial changes of land cover pattern were analyzed.Combined with the spatial pattern change rule of land cover and the spatial distribution of surface temperature,the influence of oil sand mining on the change of surface temperature is explored.According to the main research content of this paper,the following research results and understanding are obtained:(1)Based on the Landsat-8 OLI/TIRS and Landsat-5 TM remote sensing images,the land cover pattern mapping of the study area was carried out,and the temporal and spatial change characteristics,laws and main driving forces of land cover pattern in the study area from 1990 to 2019 were analyzed.From 1990 to 2019,the vegetation cover decreased,the mining land increased gradually,and the exposed surface area of oil sand mine also increased gradually,which caused the temporal and spatial changes of land cover pattern in the study area.(2)With the continuous exploration of oil sand mine and the oil sand outcropping on the surface,the cost of oil sand mining is reduced,and the economic benefits are obviously increased.The expansion of oil sand exploitation scale is the most fundamental driving force for the change of land cover pattern.(3)Based on the thermal infrared band of Landsat-8 OLI/TIRS and Landsat-5 TM remote sensing images,the spatial distribution of surface temperature in oil sand mining area from 1990 to 2019 is analyzed,and the temperature grade is divided.The total surface temperature in the study area has been increasing in the past 30 years,and the area of each temperature range has gradually concentrated to the area with higher temperature.In 1990,88.5% of the land surface temperature in the study area is concentrated in the temperature range of 11.5-24.5 ?.By 2019,88.9% of the land surface temperature in the study area is concentrated in the range of 24.5-37.5 ?.(4)Through the spatial analysis of land cover pattern and land surface temperature distribution,it can be seen that the area of high-temperature area increases gradually from 1990 to 2019,and the proportion of mining land in high-temperature area is increasing,which has obvious positive correlation with the rise of surface temperature,and the proportion of vegetation cover is decreasing,which has obvious negative correlation with the rise of surface temperature.The spatial and temporal variation of land cover pattern is the most direct reason for the spatial distribution change of land surface temperature.The expansion of oil sand mining scale is the most fundamental driving force for the increasing of surface temperature over time in the study area.