Landscapes Forest and Global Change - ESA - Escola Superior ...

M. Akbarzadeh & E. Kouhgardi 2010. Mapping and monitoring land cover and land –use changing using RS and GIS
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In order to increase the accuracy of land cover mapping of the two images, a cillary data and the
result of visual interpretation were integrated with the classification result using GIS in order to
improve the classification accuracy of the classified image.
Table1. Classification details of land covers classes in study area
Class
Details
Forest stands
Range land
Cropland
Bare land
River
Village
Mountainous forest stands ,which almost coppice
stands and low
forests including in study area. The area have the biggest forest stand in North
West of Iran.
Areas which no ability for agriculture and forestry
grasses. Some range lands is part of
positive line of ecosystem changing.
but have
changing biocenose at
Lands which cultivated vegetables, fruits, and annual crops. These crops are
irrigated mainly from the water of rivers Aras Ilghine chay , or rain water and or
ground water.
Land areas of exposed soil surface as influenced by human impact mainly or
natural causes. That is the last trying of ecosystem to protect its biocenose.
Aras and Ilghineh chay are two main rivers in study area and main resources for
irrigation of croplands and human uses, after this, the area including springs.
The biggest population community where human society is in it, at the study area.
The place of villages did not change during the time of this study so they were
not included in our classifications.
2.5 Land cover/use change detection
Regardless of the techniques used, the success of change detection from imagery will depend
on both the nature of the change involved and the success of the image pre processing and
classification procedures. If the nature of change within a particular scene is either abrupt or at a
scale appropriate to the imagery collected then change should be relatively easy to detect.
Problems occur only if spatial changes are subtly distributed and hence not obvious within any
image pixel (Milne, 1988, Darvishsefat et al, 2002).
In the case of the study area chosen, field observation and measurement have shown that the
change between the image collection dates was both marked and abrupt .In this study post -
classification change detection technique was applied. Post classification is the most abvious
method of change detection, which requires the comparison of independently produced
classified images. The CROSSTAB module of Ilwis software was used for performing cross
tabulation analysis. CROSSTAB performs two operations.
The first image cross tabulation in which the categories of one image are compared with those
of a second image and of the number of cells in each combination is kept in tabulation. The
result of this operation is a table listing the tabulation totals as well as several measures of
association between the images.
Forest Landscapes and Global Change-New Frontiers in Management, Conservation and Restoration. Proceedings of the IUFRO Landscape Ecology
Working Group International Conference, September 21-27, 2010, Bragança, Portugal. J.C. Azevedo, M. Feliciano, J. Castro & M.A. Pinto (eds.)
2010, Instituto Politécnico de Bragança, Bragança, Portugal.