Land Cover Changes And Wildfire Possibility Assessment Along Power Line Corridors By Satellite Remote Sensing

The high voltage power line in China is long and widely distributed.Power line corridors located in South and center China have greater tendency to be caught by wildfire,because of its varied terrain surface and thick vegetation.Wildfire not only destroyed the environment,ruined the surface of the earth but also led to the power line to stop work,which is really a great threat to the function of power system.This paper combined domestic high resolution optical satellite image(GF-1,GF-2,ZY-3)and utilize object-oriented classification method to extract land covers of ultra-voltage power lines in Hubei province(buffer of a 1.5km radius)as water,bare land,construction area,wood land and farmland.Besides,the accuracy of three H-R satellite images is contrasted.The vegetation area around wildfire accident area is further fine classified into dense forest and sparse forest,it was found that there was a higher possibility for wildfire accident in sparse forest.What's more,Xianning was studied to analyze the changes of land cover during 2010-2015,using domestic H-R satellite images series,the results showed that woodland decreased while construction area increased,which may account for the increasing wildfire accidents during the period.Based on analysis of forest wildfire,various factors those affect wildfire were introduced considering the characteristics of power line corridors,they are NDVI,vegetation types,weather,human activities,historical wildfire,grave points and so on,several forest wildfire possibility assessment models were deduced.After that,NDVI,percentage of precipitation anomaly and historical wildfire were applied as variables to dynamically assess the possibility of wildfire.The historical wildfire accident data was used to verify the results,it was found the assessment was in correspondence with the true wildfire accident data,which proves that the result can be used to map wildfire risk map,in order to plan ahead for prevention of wildfire.In general,this paper analyzed the changes of land covers and assessed the wildfire possibility of power line corridors based on satellite data.Combined with the characteristics of Hubei power line,high resolution satellite image data like GF-1,Zy-3 are introduced,combined with MODSI data and vegetation condition,climate,to assess wildfire possibilities in power line corridors.According to the assessment,different grades of wildfire are allocated,as a reference for the maintenance of power line corridors,which can be used to instruct management of the power line corridors and serves as a powerful technical support.