Free and open access to the Landsat archive has enabled the implementation of national and global terrestrial monitoring projects.Herein,we summarize a project characterizing the change history of Canada’s forested e...Free and open access to the Landsat archive has enabled the implementation of national and global terrestrial monitoring projects.Herein,we summarize a project characterizing the change history of Canada’s forested ecosystems with a time series of data representing 1984-2012.Using the Composite2Change approach,we applied spectral trend analysis to annual best-available-pixel(BAP)surface reflectance image composites produced from Landsat TM and ETM+imagery.A total of 73,544 images were used to produce 29 annual image composites,generating∼400 TB of interim data products and resulting in∼25 TB of annual gap-free reflectance composites and change products.On average,10%of pixels in the annual BAP composites were missing data,with 86%of pixels having data gaps in two consecutive years or fewer.Change detection overall accuracy was 89%.Change attribution overall accuracy was 92%,with higher accuracy for standreplacing wildfire and harvest.Changes were assigned to the correct year with an accuracy of 89%.Outcomes of this project provide baseline information and nationally consistent data source to quantify and characterize changes in forested ecosystems.The methods applied and lessons learned build confidence in the products generated and empower others to develop or refine similar satellite-based monitoring projects.展开更多
Free and open access to the Landsat archive has enabled the detection and delineation of an unprecedented number of fire events across the globe.Despite the availability and potential of these data,few studies have an...Free and open access to the Landsat archive has enabled the detection and delineation of an unprecedented number of fire events across the globe.Despite the availability and potential of these data,few studies have analysed residual vegetation patterns and/or partial mortality of fire across the Canadian boreal forest,and those available,are either incomplete or inaccurate.Further,they all differ in the methods and spatial language,which makes it difficult for managers to interpret fire patterns over large areas.There is an urgent need for methods to help unify fire pattern observations across the Canadian boreal forest.This study explores the capacity of the Landsat data archive when coupled with a recently developed fire mapping approach and a robust spatial language to characterize and compare tree mortality patterns across the boreal plains ecozone,Canada.With 507 fires 2.5 Mha mapped,this study represents the most comprehensive analysis of mortality patterns for study area.Summaries from this demonstration generated an accurate characterization of the fire patterns the various ecoregions based on seven key fire metrics.The comparison between ecoregions revealed differences in the amount of residual vegetation,which in turn suggested various climate,topography and/or vegetation ecosystem drivers.展开更多
文摘Free and open access to the Landsat archive has enabled the implementation of national and global terrestrial monitoring projects.Herein,we summarize a project characterizing the change history of Canada’s forested ecosystems with a time series of data representing 1984-2012.Using the Composite2Change approach,we applied spectral trend analysis to annual best-available-pixel(BAP)surface reflectance image composites produced from Landsat TM and ETM+imagery.A total of 73,544 images were used to produce 29 annual image composites,generating∼400 TB of interim data products and resulting in∼25 TB of annual gap-free reflectance composites and change products.On average,10%of pixels in the annual BAP composites were missing data,with 86%of pixels having data gaps in two consecutive years or fewer.Change detection overall accuracy was 89%.Change attribution overall accuracy was 92%,with higher accuracy for standreplacing wildfire and harvest.Changes were assigned to the correct year with an accuracy of 89%.Outcomes of this project provide baseline information and nationally consistent data source to quantify and characterize changes in forested ecosystems.The methods applied and lessons learned build confidence in the products generated and empower others to develop or refine similar satellite-based monitoring projects.
基金Saskatchewan Environment,fRI Research Healthy Landscapes Program,the government of the Northwest Territories,Bandaloop Landscape-Ecosystem Services,and an NSERC Discovery and Engage grant to Coops(RGPIN 311926-13 and EGP 503226-16).
文摘Free and open access to the Landsat archive has enabled the detection and delineation of an unprecedented number of fire events across the globe.Despite the availability and potential of these data,few studies have analysed residual vegetation patterns and/or partial mortality of fire across the Canadian boreal forest,and those available,are either incomplete or inaccurate.Further,they all differ in the methods and spatial language,which makes it difficult for managers to interpret fire patterns over large areas.There is an urgent need for methods to help unify fire pattern observations across the Canadian boreal forest.This study explores the capacity of the Landsat data archive when coupled with a recently developed fire mapping approach and a robust spatial language to characterize and compare tree mortality patterns across the boreal plains ecozone,Canada.With 507 fires 2.5 Mha mapped,this study represents the most comprehensive analysis of mortality patterns for study area.Summaries from this demonstration generated an accurate characterization of the fire patterns the various ecoregions based on seven key fire metrics.The comparison between ecoregions revealed differences in the amount of residual vegetation,which in turn suggested various climate,topography and/or vegetation ecosystem drivers.
