Transect

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A transect is a path along which one records and counts occurrences of the phenomenon of study (e.g. plants noting each instance).

It requires an observer to move along a fixed path and to count occurrences along the path and, at the same time, obtain the distance of the object from the path. This results in an estimate of the area covered, an estimate of the way in which detectability increases from probability 0 to 1 as one approaches the path. Using these two figures one can arrive at an estimate of the actual density of objects.

The estimation of the abundance of biological populations (such as terrestrial mammal species) can be achieved using a number of different types of transect methods could be used, such as strip transects, line transects, belt transects, point transects[1] and curved line transects.[2]

New Urbanist town planners use the term transect to refer to the varieties of land use from an urban core to a rural boundary.[3] General New Urban transect classifications (from highest to lowest density) are: urban core, urban center, general urban, suburban, rural, and natural.[4]

References

  1. Buckland, S.T., Anderson, D.R., Burnham, K.P and Laake, J.L. 1993. Distance Sampling: Estimating Abundance of Biological Populations. London: Chapman and Hall. [1]
  2. Line Lex Hiby, M. B. Krishna 2001. Transect Sampling from a Curving Path. Biometrics. 57(3):727-731 [2]
  3. Transect applied to regional plans. September 2000. New Urban News. [3]
  4. Transect. Duany Plater-Zyberk & Company (DPZ). Undated. [4]

See also