جستجوی مقالات مرتبط با کلیدواژه « ناپایداری » در نشریات گروه « محیط زیست »

Development of buildings and the widespread usage of the southern ranges of the Alborz ecosystem and Darabad watershed have led to unsustainable growth in this region such that continuation of this situation will destroy this ecosystem. The aim of this research is to identify unsustainable land use changes and practices in Darabad watershed through studying these characteristics.
The research method is a descriptive-analytical one, with the information gathering library-based and use of a spatial analytical method and the Delphi technique. Satellite images of TM1990, ETM 2004 and IRS2014 in four classes covering vegetation, built-up areas, arid areas and roads have been used for identifying unsustainable land use changes and practices in the case study area by using the Brovey algorithm and the Maximum Likelihood Method for the supervised classification algorithm and image enhancement. The research domain is Darabad watershed, and the statistical group comprised experts of environmental sciences, geography and natural resources.
Research results show that vegetation has decreased during the period 1990 to 2014, while built-up areas, arid areas and roads have increased in this period. In 1990, more than 20% of the area was vegetation, while this land use has decreased to less than 20% in 2014. Built-up areas and roads also increased from 40% in 1990 to 61.5% in 2014. This trend shows unsustainability in that ecosystem.
Results show that multiple factors affect the sustainability of Darabad watershed. These include ecological-geographical, economic-organizational and socio-cultural factors. Economic-organizational factors have the greatest efficiency among all the factors with a coefficient of 0.5824. Some effective variables in this regard are the widespread activity of ecotourism, lack of supervision procedures and an incorrect politicaleconomic relationship in developing build-up areas.

Earth movement is one of natural hazards which affects sustainability of our environment. In this research, on slopes facing Hamedan city (W. Iran), the hazards of natural movements have been studied by Brunsden (1994) methods, using GIS (Arc GIS 9) in scale of 1:25000. The hazard been classified in 3 groups of A, B and C. The results indicate that 64% of slopes facing Hamedan city is unstable to relatively unstable, which this hazard should be considered in development planning of the city.