Investigation on Dynamic Supervising Methods In North Part of Shaanxi Province

摘要

In order to have an objective understanding of the status that vegetation is resumed and the progress that the eco-environment construction project makes in Shaanxi province, we utilized the year of 1997 as a base in our investigation and did the dynamic supervising for the variations in the north part of Shaanxi province under the support of 3S technology. The major task of the dynamic supervising had been completed by the software of ERDAS IMAGINE. Three dynamic supervising methods are used: (1) Difference value or ratio value of TM images from two different periods was calculated and the area of variation was obtained. (2) TM remote sensing images from the two different periods are merged, based on which the corresponding relationship between the zone where the spectrum property changed abruptly and the variation of practical use of land was found. (3)Spectrum curves for different ground objects in different areas were established on the basis of the classified result of 1997. According to those curves, the present classified diagram was made and the variation diagrams of the land using were obtained after comparing these two classified diagrams.