Determination of suitable indices for vegetation cover assessment in summer rangelands in south of Mazandaran

Abstract

In order to determine suitable indices for vegetation cover and production assessment based on remote sensing data, simultaneous digital data with field data of summer rangeland in south of Mazandaran province were analyzed. During 3 years monitoring vegetation cover including annuals, grasses, forbs and shrubs and total production data of sixty plots in each site (1 square meters) were collected. The Global Positioning System (GPS), geometric correction, histogram equalization and images digital numbers were converted to reflectance numbers. In the next stage, intrinsic indices, soil-line related indices and atmospheric corrected indices were generated. For determining suitable indices, linear regression model was used. The results showed that there are significant relationships between satellite data and vegetative characteristics. Among indeces, VI10 with annual covers, VI6, VI10, MIRV1 with grasses cover, PD312, VI9, MIRV1, GVI indices with forbs cover, MIRV2, VI6, VI10 with shrubs cover, VI12, MIRV2, VI5, fuse2 and total cover and MIRV1, MIRV2, VI5, Tgr with total production, showed significant relationships. Generally introduced indices presented accurate quantitative estimation of the parameters. Therefore, it is possible to estimate vegtation cover and range production as important factors for range monitoring using landsat ETM+ data.

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