Usage of Spectral Indices in Monitoring of Green in the Selected Parts of the Pardubice Region (the Czech Republic)

Abstract

The aim of the project was to evaluate the possibility of using spectral indices in the monitoring of the green in part of the Pardubice region, namely municipality with extended powers Pardubice. Five Landsat datasets were selected in the time period from 1987 to 2013. The processed data comes from Landsat 5, Landsat 7 and Landsat 8 satellites. Next three scenes were taken from the Terra satellite MODIS scanner. Images were selected in such a way that the acquisition dates were approximately the same. Four vegetation indices were compared: ratio index NDVI, SAVI and MSAVI distance indexes, and orthogonal index GVI. A temporal analysis was carried out for these indices between 1987 and 2013. An unsupervised classification was performed to better interpret the images. Data were classified by ISODATA algorithm into fifteen classes, which were then aggregated into three classes. A majority filter was used for smoothening the classified results. NDVI and SAVI values show almost identical results in the area of interest and there were no significant differences after the classification. MSAVI versus NDVI and SAVI index is less sensitive to capture of concrete surfaces. The water areas were classified correctly. The GVI vegetation index differs considerably from NDVI, SAVI and MSAVI indices. After classification, GVI ranked green areas similarly to other indices. However, agricultural land was largely included in the class of water areas. Therefore, GVI is inappropriate to analyse the green of areas of interest. The best results are provided by the classified MSAVI. The minimum of concrete surfaces were assigned into the class of water bodies. At the end of the work, the detection of green changes was calculated. Changes between 1987 and 2013 were most evident in the southern part of the area. The highest changes in vegetation identified GVI index.