Estimation of Vegetation and Land Use Changes Using Remote Sensing Techniques and Geographical Information System (Case Study: Roodab Plain, Sabzevar City)
Authors
Abstract
Land use may be regarded as one of the most important factors affecting the
environment with respect to human activities. So far, destroying the rangelands and
changing them into the waste lands and poor rangelands has been proposed as the most
significant variations of land use done by human beings. This paper has been conducted to
evaluate the variations of vegetation percentage and land uses in Barabad-Darook village
with the area of 1522.99 km2 in Sabzevar city during 1987-2007. Thus, using satellitebased
images of TM and ETM+, the most appropriate band composition has been selected
and a mapping of vegetation cover and land use was provided through maximum
likelihood algorithms to correct the errors of geometer and radiometer highlights. At last,
the accuracy of extracted maps was to be determined by the means of overall accuracy test
and Kappa coefficient in order to achieve the validation of research process. Results
indicate that waste lands have been increased from 84.75 to 89.49 and third-rated
rangelands have been reduced from 6.85 to 4.14 percent. On the other hand, first-rated
rangelands were reduced from 0.03 to 0.01 percent which covers 5170791.45 m2 of total
area in the district. Also, the results show that irrigated agricultural lands are to be
decreased from 6.53 to 0.07 percent. In total, due to improper exploitations of regional
water resources and vegetation cover, land uses have been changed into fallow and waste
lands leading to the decrease in the percentage cover of high quality rangelands. Research
findings demonstrate that considering the accepted accuracy, new remote sensing
technology can be applied to exactly estimate the area changes of land use and vegetation.
