Study on Landscape Degradation in Neka Watershed Using Landscape Metrics

Document Type : Original Articles

Authors

1 epartment of Environment, Faculty of Natural Resource, Tarbiat Modares University

2 epartment of Environmental Planning, Faculty of Environment, University of Tehran

3 Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University

4 Department of Remote Sensing Organization, Iranian Space Agency

Abstract

Land cover/use change induced by human activities, ignoring environmental constrains caused landscape degradation. The continuous land use change has also severe impacts on natural ecosystems. Therefore, in consideration with the negative effects of unsuitable use of land and land use change, knowledge and understanding about the changes is essential in environmental impact assessment for sustainable planning and land management .This study is for investigating the trends of changes in the landscape, in Neka Watershed. In order to provide land cover maps the satellite images of MSS 1972, TM 1992, ETM+2001 were applied and landscape metrics of class area, largest patch index, number and mean patch size were used to quantify landscape patterns. The analysis of landscape metrics revealed that the extensive replacement of agricultural lands and forests with rangelands and the results verified that increased patch number and decreased mean patch area were two important fragmentation indicators and the trend of degradation and fragmentation of the landscape was increasing. Therefore the results necessitated paying attention to the quality of land use and cover in the region for decreasing the natural resources degradation.

Keywords