changes in vegetation related to bear ranges by: aurora hagan, jaime nielsen, krista trenda
TRANSCRIPT
CHANGES IN V
EGETATI
ON
RELATE
D TO B
EAR
RANGES
BY : A
UR
OR
A H
AG
AN
, J AI M
E N
I EL
SE
N, K
RI S
TA
TR
EN
DA
OUTLINE
• Brief history on black bears
• Objectives
• Methods
• Results
• Discussion
• References
NATURAL HISTORY
Geographic Range: Alaska, Canada , NE United States, Rocky Mountains, Appellation Mountains, and Northern Minnesota
• Smaller populations found through out the US
Home Range in MN: The northern third of MN, coniferous and deciduous forest
Food Habits: Omnivores—grasses, nuts, berries, insects, fish, and human food
June and Lily
• Located in St. Louis County, MN
OBJECTIVES
• Classify vegetation in study area
• Visual vegetation change over time
• Relate analysis of vegetation to bear use
METHODS
ArcGIS 2010:
• Convert Lat/Long GPS points to UTM 1984 WGS 15N to match satellite imagery
• Separate shape files were created per bear, per month in order to relate them more directly to the time frames chosen for comparison
METHODS
ERDAS 2010/2011
• Layer stacked the 7 bands from the Landsat images to produce one pyramid layer per image
• Clipped the images to focus on the study area
• Unsupervised classification : 16-20 classes, 15 iterations, 0.95 convergence threshold
• Recoded to combine like classes
• Accuracy Assessment : Stratified Random--100 points, 10 points minimum per class
• Change detection • Oct 2008 to Sept 2011• July 2006 to July 2010• April 2010 to Aug 2010
RESULTS – 4 YEAR COVER TYPE COMPARISONJuly 2010
July 2006
RESULTS – GENERAL CHANGE DETECTION• Oct 2008 to Sept 2011
RESULTS – CHANGE IN COVER TYPE AND BEAR MOVEMENT• April 2010 to August 2010
DISCUSSION – PROBLEMS!
GPS points –
• 2008 – limited points over a 2 month period
• October 2010 – limited points for June
• Inconsistent collection intervals
Landsat imagery –
• Must have Level 1 downloadable data• Limited our ability to directly match GPS points to images
• Clouds are pretty, but not in my image
• Lack of 2009 images
DISCUSSION – PROBLEMS!
NAIP imagery –
• Files are HUGE• Need a large GB flash drive
• The images aren’t user friendly
ERDAS –
• Images were classified and recoded differently for July 2006 and July 2010• Caused an unusable change detection map
DISCUSSION – UNUSABLE CHANGE DETECTIONChanges in all classes from July 2006 to July 2010
DISCUSSION – WOULD HAVE DONE DIFFERENTPlanning
• Looked at the GPS data first to help decide time ranges
• Looked at what imagery from GloVis was Level 1
• Learn how to correct pixels of cloud cover
REFERENCES
• Special Thanks to Dr. Lynn Rogers and Sue Mansfield
• Thanks to Professor : Joe Knight, Teacher Assistants : Lian Rampi
and Jennifer Corcoran
QUESTIONS??
????
??