the solar radiation received by earth surface is one of the most applicable parameter that is so important in hydrology, agriculture, meteorology and climatological modeling. because of very expensive instrument for measuring the radiation, researchers suggested many different experimental equations to estimate this parameter in different climate. seven models which are calibrated for semi-arid...

This paper reports the study of the effect of the length of the recorded data used for monthly rainfall forecasting. Monthly rainfall data for three periods of 5, 10, and 49 years were collected from Kermanshah, Mashhad, Ahvaz, and Babolsar stations and used for calibration time series models. Then, the accuracy of the forecasting models was investigated by the following year’s data. The follow...

A new challenge which the world will face in near future is the reduction of water resources regarding to global climate changes. Climate change is one of the phenomena which will threats future of the universe. Iran locates in an arid and semi-arid region and has limited water resources. Based on global and Intergovernmental Panel on Climate Change (IPCC) board database and the statistics of s...

soil biodiversity is the origin of considerable goods for maintenance and extension of above ground biodiversity and environmental soundness. this study was carried out in shirvan, mashhad and gonabad, three regions of razavi and northern khorasan provinces, to determine soil characteristics and biodiversity in natural systems of arid and semi-arid regions. in each studied system, 10 locations ...

1. introduction during the past decade, many efforts for investigating the relationship among air pollution and meteorological factors have been undertaken and some statistical methods have been proposed. population increase and technological advancement were among the factors affecting creation and extension of air pollution in big cities, forcing large cities all over the world to contemplate...

Bagherzadeh A., Paymard P. (2015): Assessment of land capability for different irrigation systems by parametric and fuzzy approaches in the Mashhad Plain, northeast Iran. Soil & Water Res., 10: 90–98. Water quality and quantity in agricultural systems of arid and semiarid regions of the world are of great importance. In this regard the trend to pressurized irrigation systems compared to surface...

This paper reviews the main methodologies and techniques that have been used to characterize gypsum in soils, especially in gypsiferous soils of semiarid and arid regions and range from the identification of gypsum in soil surveys in the field to the study of gypsum in the laboratory. Many methods of gypsum identification and determination have been developed, each one with its own limitations....