The use of TM imagery to monitor the general health of coastal marshes /

(prepared by using training sites from the National

Bibliographic Details
Main Author: De Sousa, David Alexandre
Format: Thesis eBook
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1994.
Subjects:
Online Access:Link to OAKTrust copy
Description
Summary:(prepared by using training sites from the National
accurate and reliable assessments concerning marsh health
and a 1990 Winter scene were overlaid for change-detection
and no-change errors. As was the case in this study, the
any degradation and loss, causing unintentionally-introduced
are possible. The traditional 2-layer overlay procedure
be used more efficiently, by channeling resources directly
because of field work and personnel required, the procedure
between true-change and no-change situations, from change
but less harsh conditions may give promising results. The
change detection, in that two varied sources of information,
clarity to warrant quantitative investigations to evaluate
classes do not seem likely under the conditions stipulated,
classifying an image to be used as a GIS layer in the 2-
concerning alterations in the study area, except that which
conditions of the test. These were: (1) seasonal
could be extracted from the images and the NWI Map, and 5)
DeSousa procedure, or modifications thereof to suit specific
detected, at little expense; therefore limited budgets can
differences, 2) no ground-truthed image, 3) no field work to
difficult conditions. The classes were much cleaner (less
digitally produced maps.
each image to be studied. Therefore, a 4-layer overlay is
error, by unrealistically shifting the water regime to a
excessive care by the image-processing operator to capture
field-corrected, 4-layer overlay appears to be of such
General marsh-health monitoring without field observations
guide the image processing; 4) no information used
health were possible. The interpretations given in this
Imagery. As monitoring is very expensive and time-consuming
its full potential (not the subject of this study).
layer over- Jay, each pixel is given a classification that
layer overlay procedure for change detection. It involved
logical mapping unit, and eliminates error. The results are
may be correct or not. There is information to distinguish
modelled out of the change-detection process; thus more
much drier one.
much superior to those of 2-layer processing. Applying the
offer more information to be processed in a GIS. Errors are
pern-tits no truly convincing means to correct errors. When
Practically all areas of digital map making can benefit from
prepared. The 4-layer overlay has superior structure for
procedure was devised and compared to the traditional 2-
processed change-detection map difficult conbecomes speckled
processing of TM imagery permits classifications to the most
proposed should cut costs. Areas of declining health can be
requirements, can greatly enhance the quality of most
speckled with error). Interpretations concerning marsh
study are visual. Area quantification of marsh-health
The 4-layer overlay procedure fared well under these
the concepts involved in the procedure proposed. Multi-layer
to be interpreted into general marsh-health classes. A new
to locations where they are needed. Preprocessed imagery
using a supervised and an unsupervised classification of
was demonstrated to be feasible using TM (Thematic Mapper)
Wetlands Inventory Map for the area) of a 1983 Summer scene
with error. The 2-layer overlay could not cope with the
Item Description:"Major subject: Geography".
Vita.
Physical Description:x, 73 leaves : illustrations, maps ; 28 cm.
Also available online.
Bibliography:Includes bibliographical references.