introduction there are significant differences in the spatial distribution of the iran annual precipitation. this is resulted from spatial behavior of precipitation in the one hand and variation in the sources of precipitation on the other. the lack of adequate distribution of meteorological stations and the unavailability of long-term statistics of precipitation makes the analysis of precipita...

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...

prediction of annual average precipitation over a regin is one of important issues in watersherd management and natural resources planning. geostatistics is one of the useful methods for precipitation prediction which varies based on type of the variable. this study was conducted in karoon and dez basins located in southwertern of iran. the data set including 20 years of annual precipitation of...

Future climate change has been predicted to affect the potential distribution of plant species. However, only few studies have addressed how invasive species may respond to future climate change despite the known effects of plant species invasion on nutrient cycles, ecosystem functions, and agricultural yields. In this study, we predicted the potential distributions of two invasive species, Rum...

climate change impacts on precipitation and temperature world-wide are not yet well understood (especially for precipitation), due to their complexity and regional variability. in this study in order to explicit the impact of climate change on precipitation and temperature in iran, 15 aogcm whose greenhouse gases scenarios ran under a2, a1b and b1 were used. monthly precipitation and temperatur...

This paper presents the result of the regional coupled climatic and hydrologic model of the Nile Basin. For the first time the interaction between the climatic processes and the hydrological processes on the land surface have been fully coupled. The hydrological model is driven by the rainfall and the energy available for evaporation generated in the climate model, and the runoff generated in t...

We simulate the effect of climate change on water requirements of cold seasonwheat in various climatic zones of Iran. The research considers both observedclimate (temperature and precipitation) changes during recent decades (1960-2009)based on instrumental records and projected future changes to 2100 based on theMAGICC/SCENGEN 5.3 compound model. 20 General Circulation models are usedbased on a...

Local climate and environment broadly affect the deuterium/hydrogen (D/H) ratios of plant materials, however the degree to which an individual plant’s leaf waxes D/H ratios are affected by these parameters remains in question. Understanding these issues is particularly important in order to reconstruct past floral transitions and changes in the paleohydrologic cycle. For this study, we sampled ...

To obtain a better understanding of the variability in net primary production (NPP) in savannas is important for the study of the global carbon cycle and the management of this particular ecosystem. Using satellite and precipitation data sets, we investigated the variations in NPP in southern African savannas from 1982 to 2010, and disentangled the relationships between NPP and precipitation by...