introduction: wind erosion is one of the most important factors in desert environments. prevailing winds can shift sand dunes and affect their accumulation and morphology. also, wind regime determines the direction of sand dune mobility in different ways. therefore, the wind regime, frequency, direction and velocity are supposed to be the most important factors to form the morphology of sand du...

drought, as a normal, recurrent climatic condition with complicated mechanism, is one of the least known natural disasters that may occur in any climatic condition. considering the recent drought events in the iran and the deterioration of water crisis, especially in the area under study, the necessity of further research in this area is felt. also, the evaluation and monitoring of drought with...

abstract spi is based on fitting a gamma distribution to precipitation amounts in selected periods. based on current research, the gamma distribution may not be fitted to annual precipitation of some regions. in order to evaluate this subject, annual precipitation have been used during 1958- 2007 at 11 synoptic stations in iran. in first step, values of spi and frequency of different classes of...

This paper attempts to establish an evaluating index system of land comprehensive carrying capacity in Xi'an city involving three aspects, such as economic carrying capacity, social carrying capacity, and ecological carrying capacity, combined with the development goals and constraint factors of Xi'an city. Furthermore, we adopted the method of mean-squared deviation weight decision to evaluate...