The linear transect:
“windshield survey”
A very common and useful reconnaissance technique is the linear transect. A linear transect allows the geographer to extrapolate a limited set of field observations into a description of a fairly large area. In some situations, a linear sampling scheme may be the only viable option for field checking of remote sensing data. For example, vegetation mapping of the vast interior of Siberia… without a massive investment in a field campaign it would be impossible to perform a true random sample. The proposed solution was a stratified linear random sample. The few transport corridors would be buffered and samples taken, producing a statistically viable sample with much less investment.
Linear transects are usually laid out along paths of easy transport… while this can limit their statistical viability and leads to a biased sample… the short answer is that they are cheap, easy to lay out and often one of the best tools available for initial recon. of a field area
In your write up please consider how urban/industrial/commercial development might bias a linear transect.
Please visit
And read a bit about one of the more notable theories of development across space.
Recording data:
It is very important to record data during your transect. In educational theory it has been noted that we remember what we first see (primacy), what we last see (recency), and that which has a significant impact (the ‘oh wow’! factor). If a geographer makes a transect without the discipline to record accurate notes, he or she may ‘remember’ differently and again produce a biased result. In this exercise, you will record data at ½ mile intervals along your transect.
The ‘grain’ of the landscape:
Landscapes have patterns, this is one of the key understandings in geography, which can be defined as a search to identify and understand the patterns of a landscape.
In many cases it is desirable to construct the transect across as many features / factors of the landscape as possible. In many places the gradient on the landscape will be elevation and or climatic. Here in Northern Alabama it appears that the ‘grain’ of the landscape, in general, follows the Tennessee River. It should prove to be more instructive and produce a better sample to cross the landscape at right angles (or something approximating right angles) to the development along the Tennessee River.
The Assignment:
Working in pairs for driving safety, identify a series of roads that will lead you across the landscape roughly perpendicular to the development corridor of the Tennessee River. Make sure you reach at least 10 miles North and South across the river. (if you see interesting/significant features in the next couple of miles, feel free to add a little to your transect). Record the land use/land cover at ½ mile intervals along your route. Record changes in elevation, changes in vegetation, changing land use, changes in development density. In your write up, provide a final version of your field notes. Add a map that shows the route you chose for the transect, and describe changes in the landscape. Quantify the landscape based on your data points (X% forest, Y% pasture, Z% commercial etc….Use Anderson’s level 2 classification categories). Compare these percentages with your knowledge of the area, are your percentages a fairly accurate representation of the area as a whole? Evaluate the transect you chose, is it representative of the area? Demonstrate in your discussion that you have a good understanding of the ‘central place theory’ and how development will follow transport corridors. Are there significant differences (cultural/agricultural/development) between the North and South sides of the river? Are the differences in the landscape a function of distance from the river? Or are other factors involved?
BE SAFE!!!!!
Table 1. A part of the modified Anderson classification system illustrating subcategories included in the "developed" land use category
Level 1 / Level 2 / Level 3 / Level 42.0
Developed / 2.1 Residential / 2.11 Single-family residential
2.12 Multi-family residential
2.2 Nonresidential developed / 2.21 Commercial/Light Industry / 2.211 Major retail
2.212 Mixed/minor retail and services
2.213 Office
2.214 Light industry
2.22 Heavy industry / 2.221 Petrochemical refinery
2.3 Mixed urban