Event Title
Satellite-based western Canadian glacier inventory
Description
We utilized Landsat imagery ~2005 and existing ice polygons from provincial mapping ~1985 to produce a glacier inventory for western Canada south of 60 º N. We corrected errors in the mapping from 1985 due to late lying snow and debris cover using Landsat TM and the provincial digital terrain model (DTM) based on the same aerial images as the ice polygons. The 2005 glacier vectors were produced from a band ratio (TM3/TM5) and the 1985 outlines as a clip layer. Misclassified pixels were corrected with water and slope detection algorithms. Final polygons were manually checked for errors. We also used the provincial DTM to split the glaciers into individual flow sheds. The estimated error in our method, determined by comparison of the digital vectors to those obtained through manual interpretation, is within 2.5%. Glacier cover in British Columbia and Alberta declined by 11.5% over the period 1985-2005. The annual retreat rate 0.6% a-1 is comparable to rates reported in other mountain ranges. Work is underway to compare these rates of ice loss to climate change over the period of study.
Document Type
Event
Start Date
8-3-2008 8:00 AM
Subject - LCSH
Glaciers--Climatic factors--British Columbia; Glaciers--Climatic factors--Alberta; Glaciers--British Columbia; Glaciers--Alberta
End Date
8-3-2008 5:00 PM
Session
Glacial Studies: Inventory, Resources, Applications
Genre/Form
abstracts (summaries)
Type
event
Geographic Coverage
Alberta; British Columbia
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Language
English
Format
application/pdf
Keywords
glacier inventory, glacier recession, remote sensing
Satellite-based western Canadian glacier inventory
We utilized Landsat imagery ~2005 and existing ice polygons from provincial mapping ~1985 to produce a glacier inventory for western Canada south of 60 º N. We corrected errors in the mapping from 1985 due to late lying snow and debris cover using Landsat TM and the provincial digital terrain model (DTM) based on the same aerial images as the ice polygons. The 2005 glacier vectors were produced from a band ratio (TM3/TM5) and the 1985 outlines as a clip layer. Misclassified pixels were corrected with water and slope detection algorithms. Final polygons were manually checked for errors. We also used the provincial DTM to split the glaciers into individual flow sheds. The estimated error in our method, determined by comparison of the digital vectors to those obtained through manual interpretation, is within 2.5%. Glacier cover in British Columbia and Alberta declined by 11.5% over the period 1985-2005. The annual retreat rate 0.6% a-1 is comparable to rates reported in other mountain ranges. Work is underway to compare these rates of ice loss to climate change over the period of study.