according to the importance of obtaining accurate informations on drought conditions and it risk management for water right of major wetlands in iran, in this study climatic coefficients of palmer index for 17 watersheds in country was calibrated and zonation and their range in basins containing international wetlands were investigated. results showed that in wet conditions, in basins such as c...

Semi-arid rangelands show much spatial heterogeneity, with some parts producing more and better quality food for herbivores. The concepts of ‘Key Resource’ and ‘Key Resource Area’ have been developed to describe a resource that ‘provides good-quality forage’ and that ‘reduces (inter-)annual variation in forage supply’. Illius and O’Connor (1999) formalised these concepts, arguing that in key re...

PURPOSE To describe the features of intraretinal retinal pigment epithelium (RPE) migration documented on a prototype spectral-domain, high-speed, ultrahigh-resolution optical coherence tomography (OCT) device in a group of patients with early to intermediate dry age-related macular degeneration (AMD) and to correlate intraretinal RPE migration on OCT to RPE pigment clumping on fundus photograp...

northern khorasan province is located in north-east iran. according to demarton coefficient, it is a semiarid region. arid and semi-arid or subhumid zones are characterized by temperature variations, low and erratic rainfall, periodic droughts and different associations of vegetative cover and soils. this article looks at current dry lands and general guidelines for finding the best area for dr...