today, climate change is one of the most important scientific and even the political – social issues. the causes of climate change can be divided into natural and human - made. natural factors have the long-term performance and long history, such as the cycle of solar activity, dusts and gases of volcanic eruptions, geodetic and static agents and etc. human-made factors was mainly formed and ac...

introduction the coastal zone is one of the greatest environmental and economic assets of each nation. in coastal regions the natural forces that cause shoreline changes are embodied in waves, currents, wind and other factors. gorganroud river delta is located in 53°57 to 54° 1 e and 36°56 to 37° n in southeast part of caspian sea. in this study, gibbosity of gorgan river delta has been studied...

risk assessment of soil erosion, one of the most important land degradation problems worldwide, is very essential for land and water resources management, and development of soil conservation methods. in the present study, the temporal changes of soil erosion risk were assessed from 1987 to 2010, based on the revised universal soil loss equation (rusle) using remote sensing (rs) and geographic ...

The study of the exclosure effects on the vegetation changes undergrazing and non-grazing conditions in the rangeland areas has particularimportance in the rangeland improvement and revivification projects. Theresearch was accomplished in semi-steppe KhoyBilehvar area, from 1999 to2005. Vegetation cover was annually measured within fixed plots during transact.The results showed that during nine...

abstractprecipitation could be regarded as a complex and a very vital element in the earth atmosphere and its spatial-temporal changes can control iran's climate. in the current research, in order to model the spatial-temporal changes of annual precipitation, the data taking from 50 synoptic stations, have been analyzed during the years 1966-2005, with a suitable distribution. the most dat...