Elevation and Vegetation
Using Raster Data to Predict Life
Introduction
In our class that talks about the use of GIS, we've recently wrapped up our discussion of raster GIS analysis. One part about raster analysis that stuck with me was the concept of the Digital Elevation Model (DEM). It uses interpolation techniques to form a surface that attempts to reflect the elevation of the area it is modelling.
Clearly, such data would be valuable. If we have access to the elevation of an area, we can begin to talk about what kind of effects that elevation has on any number of variables that we would want to investigate. One such variable that I want to talk about today: Vegetation.
An analysis like this could be useful. If it's found that elevation does have an influence on vegetation, then the implication appears to be that being at a certain elevation may benefit/hinder agriculture in that area. Vegetation may also impact urban sprawl, and so city planners may want such information when considering city expansion.
Data Format
We know what it is that we want to find: A model for elevation and an indicator for the amount of vegetation in areas. We can model elevation using a DEM, as explained above. We also know about an effective tool for collecting information about vegetation: Infrared scanning. Because plants can emit electromagnetic radiation in the infrared boundaries, we know that picking up these radiation emissions should give us an idea of where the vegetation is.
This may be problematic however, as this scanning may not give us enough information about how much vegetation is in an area. Depending on the sensitivity of the scanner, it may function as an absence/presence type of data. This is a factor that will have to be explored in during research.
Procedure
I will be updating this project heading over the next few days with my documenting the steps I have taken to research and
obtain the data to perform this analysis.
It appears as though there is a source of data for our DEM. The Geogratis website provides topographic data via its data extraction tool. It appears as though you have to request the data, so that's what we'll do. Previously, we would have done the entire province of British Columbia. However, this is a large set of data, and we may not benefit from such an extensive study. Instead, we will focus on the city of Kimberley, BC, as a kind of high elevation example. We will use other cities for other elevations when such cities are determined.The data for Kimberley, BC is available from this link. There is also data available here for the infrared sensing around Kimberley, BC.