Investigation on ecosystem degradation induced by LU/LC changes using landscape pattern indices analysis

چکیده مقاله

Notable land use change and land degradation are occurring in Iran as a result of demographic pressure and consecutive droughts. Landscape indicators are efficient quantitative metrics to assess and monitor the status of the landscape in a general description and can provide the more accurate understanding of land use and land cover. The main goal of this research was to evaluate the usefulness of landscape metrics in the context of land degradation. In this study, land use changes in the Ardabil region of Iran and in two periods of 1987 to 2014 were analyzed and compared. LU/LC maps were obtained from Landsat satellite images by using supervised maximum likelihood classification method coupled with GIS analysis and based on landscape metrics, and finally, structural and functional relations were compared. The results showed that the land use in the studied area has undergone significant changes from 1987 to 2011, half of the rangelands and forest has changed for the benefit of abandoned lands and agricultural lands since 1987. According the results, MNN metrics have declined in all land uses, which indicates the most changes have happened in the land use frontier. Also, the PSSD metrics show an increase in some land uses indicating a disproportionate size of land use classes in the landscape. The IJI metrics have increased in some land uses that indicates an increase in the dispersion of the intended land use at the regional level. The MSI index has risen in residential land use that indicates an increase in irregularity in land use form. MNN index increases in forest land use. This suggests that there is a difference between the remaining patches that have been affected by the deforestation phenomenon. All these changes are evidence of the fact that the structure of landscape goes fragmented and fine-grained under human intervention along with climate change.