Monitoring Research Of Daquanhu Coal Fire Of Urumqi In Southern Junggar Coalfield

Coal fire is a typical eco-environmental problem associated with coal mining.The present paper focuses on the Daquanhu coal fire,which is located in Southern Junggar coalfield,to investigate the change of surface temperature and vegetation coverage by retrievaling remote sensing data of this area.Basing on result of retrievaling data from 2013 to 2016,the trend of the change of surface temperature and vegetation coverage was predicted by using GM[1,1]model.In order to investigate the situation of soil contamination and gases emission from this coal fire,the soil samples were collected and analyzed,the gases were measured at the same time.Results were obtained from this research as follow:（1）From 2013 to 2016,grade one of vegetation coverage were mainly distributed in the west,the middle and the east part of this fire zone.The area of the grade one and the grade two of vegetation coverage decreases during this period.The area of the grade three increases during the same period.And it’s clear that the area of grade three and grade four increases from 45.23×10⁵m² of 2013 to 52.42×10⁵m² of2016.（2）From 2013 to 2017,the area of abnormal temperature of this fire shows the trend of fluctuation.The number of abnormal areas reduces from three sites of 2013to two sites of 2017.The total area of abnormal temperature of this fire reduces obviously since 2015.The possible reason for that is the extinction of this fire was started in the end of 2015.（3）Result from prediction of GM[1,1],the area of grade four of this fire zone will increase from 2017 to 2020.Inversely,the area of grade two and three will decrease during the same period,i.e,the percentage of the area of grade two will decrease from 17%of 2016 to 11%of 2020,and the percentage of the area of grade three will decrease from 51%of 2016 to 49%of 2020.The area of grade four will increase from 25%of 2016 to 30%of 2020.The area of abnormal temperature will decrease from 0.32×10⁵m² 2017 to 0.09×10⁵m² of 2020.（4）The content of the N of soil shows an obvious positive relationship with the temperature of soil.The contents of the P,the K and the organic matter show a negative relationship with the temperature.The contents of the Cu,the Zn,the Pb,the As and the Hg show an obvious positive relationship with the temperature.The content of the N shows an obvious positive relationship with each heavy metal.The contents of the P and the K don’t show any relationship with each heavy metal.The content of organic matter shows positive relationship with the Cu and the Cd but other heavy metals.（5）The single factor pollution index of heavy metals for the soil of the Daquanhu coal fire has the order of Hg>Cd>Cr>As>Zn>Cu>Ni>Pb.The Nemerow synthetical pollution index is 15.93.And the potential ecological hazard index is951.15.Results from above three indexes indicate there exist a serious heavy contamination in the zone.（6）Results from gases measuring,there exists different gas compositions,such as the O₂,the CO,the SO₂,the NO,the NO₂ and the NOx.The amount of gases emission from this fire was estimated as the 256.2kg of CO,the 4.20kg of SO₂,the108.60kg of NO,the 4.80kg of NO₂ and the 171.00kg of NOx respectively.Considering the impact of the change of meteorological parameters,this paper also proposed a model to quantify the impact of the fluctuation of the air temperature.Results from above research present the situation of the contamination of the soil in Daquanhu coal fire,and reveal the characteristics of gases emission from this fire.It also demonstrates the change of the surface temperature and the vegetation coverage of this fire from 2013 to 2017,including the trends after 2017,which provides the bases of evaluating the coal fire impact on environment.