1. Land Cover Mapping and Habitat Analysis
Distinguishing vegetation communities

3. Learning Objectives
Understand the difference between land cover, vegetation, ecosystems, and habitat
Understand the general procedure used for mapping land cover using remote sensing
Understand the importance of scale and MMU.
Be able to construct a classification scheme for mapping.
Understand the role of photointerpretation and interpretation keys.
Understand the importance of accuracy assessment in mapping.

4. Some definitions… Vegetation Ecosystem Land Cover Habitat
All of the plant life in a particular region (e.g., the vegetation of Wyoming) or period (e.g., Pleistocene vegetation)
Ecosystem
An interacting system of biotic (plants, animals, microorganisms) and abiotic factors (the environment)
Land Cover
All of the features occupying the land surface including vegetation, unvegetated areas, natural and human affected
Habitat
Habitat includes the physical requirements that a species requires to live.

5. Mapping land cover: General procedure
Scope the project
Acquire the remotely sensed imagery
Develop a classification scheme (map legend)
Explore the area on the ground (if possible)
Develop an interpretation key and/or spectral tools
Create land cover units (make the map)
Assess the accuracy of the product
Refine as necessary

6. Scoping the project What is the desired mapping scale?
What is the MMU?
What resources are available (data, money, etc.)?
How much time is available to do the project?
How accessible is the map area?
Etc.

7. Minimum Mapping Units (MMU's)
The minimum mapping unit is the smallest contiguous area that will be digitized or classified on your map.
Important decision because it determines what patch sizes will be retained
Will have different effects on map depending on the spatial configuration of the area (e.g., is the area homogeneous or patchy)
Sometimes maps have different MMUs for some types (e.g., riparian) than others
MMU lower limit defined by resolution of the imagery

8. MMU determines which clearcuts get mapped
Copper Mountain, Colorado (IKONOS image)

9. Acquiring imagery for mapping
What qualities does the imagery need to have to accomplish the mapping task?
Dates/times
Spatial scale/resolution
Spectral resolution (panchromatic, true color, false color IR, etc.)
Geometric properties (orthorectified, vertical, oblique, etc.)
Amount of overlap for stereo viewing, etc.
Are suitable images available (e.g., NAIP, satellite)?
Are contractors available to fly if no archive is suitable?
Costs, timing, etc.

10. Land Cover Classification Schemes
How many types do you want to map?
How should you divide up the features you are interested in?
What resources do you have?
How will your interpretation be used?
What do the funders want!
Can be very controversial!

11. How would you classify this produce?

12. Characteristics of classification schemes
Must be useful
Types must be detectable using the data you have
Should be hierarchical
Categories must be mutually exclusive
Require explicit definitions of each class

13. Example of a simple hierarchy
Vegetated
Forest
Evergreen
Spruce-fir forest
i. Spruce-fir with winterberry understory
Lodgepole pine forest
etc.
Deciduous
Shrubland
Non-Vegetated

14. Exploring the ground (field recon)
Critical for understanding the distribution of land cover in the real world
Helps you choose useful ancillary data
Useful for understanding images back at the computer
Nice to get outside!

15. How would you classify this vegetation and where are the boundaries??

16. Interpretation keys Interpretation keys should include the following:
Explicit written description of each type in the classification
Examples of each type as it appears in the aerial photography being used
A list of key features of the type that can be used to distinguish it from other types
Can take the form of a dichotomous key like you would use for keying out plants or animals
Should be organized into an easy-to-use notebook or in some kind of digital format (e.g., hyperlinked web key)

17. Image interpretation key for forest types in Vermont

18. Photointerpretation/classification
Classification can take two basic forms:
Manual photointerpretation of imagery
On hard copy using clear overlays or other tools
On computer screen by digitizing with mouse
On tablet using a stylus
Per-pixel classification of digital imagery
Not used as commonly with aerial photography because the spectral data are not as good as in multispectral satellite imagery.
Will talk about this more in the context of satellite data

19. Detailed view of Wyoming GAP Land Cover Map

21. Wetland community mapping – University of Wisconsin

22. Horticulture map at University of Wisconsin
Individual shrubs delimited with carefully rectified orthophoto

23. Assessing accuracy
Accuracy assessment is crucial for any mapping project
Requires extensive field work to compare what is on the ground to what is designated on the interpreted photo
Can be expensive – field work costs money
Can be quantified using a suite of accuracy assessment metrics

24. Product refinement If product accuracy is not sufficient, must refine
Assess the original data – are problems related to the information content of the imagery?
Assess the interpretive process – are problems related to inconsistent or poor image classification?
Does the interpretive key need to be revised/amended?
Assess the classification scheme – is the list of types appropriate and mappable.
Would moving “up” the hierarchy be useful and if so would the map still be appropriate for users?

25. Using land cover data to create habitat maps
Habitat is usually a combination of land cover with other spatially distributed environmental drivers
Climate
Soils
Proximity to water
Availability of cover
Contiguity of cover types needed for different parts of the life cycle
Availability of food/prey
Etc.
Typically combine these as spatial layers in a GIS

27. GIS Habitat model schematic for Wild Boar

28. Summary
Land cover is the collection of features occupying the land surface
Air photos are useful for mapping land cover, especially at fine scales
Land cover mapping is a process with a series of important steps, each of which must be carefully executed
Our ability to accurately map land cover can be limited by the quality of the photography or other data that we are interpreting
Important to be realistic about what can be accomplished