- Slides: 4
Creating a Transect A transect is a line following a route along which a survey or observations are made. The transect is an important geographic tool for studying changes in human and/or physical characteristics from one place to another. An urban transect, usually following a street or several streets, may show changes in land use, the nature of buildings such as houses and shops, or features such as schools, churches, community centres, and parks. A rural transect might follow a road, section line, or stream, and show the kinds of crops in adjoining fields, farm buildings, vegetation, or changing features along a riverbank. Transects may show features that are along the actual line selected (line transect) or, more commonly, may show what is on either side of the line (belt transect). Depending on the kinds of features being observed, transects can be a single straight line, straight line segments, or curved lines.
Creating a Transect Next is a sample transect. It is a strip of land used to monitor plant distribution, animal populations, etc, within a given area. Transects are just long, narrow, quadrats. They show changes in vegetation communities such as down a slope or across a valley. If you were mapping vegetation communities from the vertical aerial photograph below, an experienced veg. mapper may pick different communities at A, B, C and D. To check your accuracy you need to do a field survey to 'ground truth' your work. You have chosen to do 3 transects going across the hill in the vicinity of A to C. You need to do a number of transects, by doing only one you may miss important plant species. Once you have selected areas which represent your different plant communities, you need to randomly select a number of transects so you do not have a biased survey. To do this go to the map at the bottom of this page, click on the transect line and drag it to the vicinity of the transect area of A, B and C then drop the transect line without looking at the map. Record your results.
A. red gum community B. casuarina community C. white box community D. cypress pine community
The diagram on the previous slide is a representation of the transect A-B-C. It is a transect 130 m long by 5 m wide with a compass bearing of 1300. At each location there is a record of the tree species and their distance along the transect.