depth of frost penetration is one of the main indices in agriculture, civil and transportation engineering. soil temperature is a function of several factors including: topography, solar radiation, air temperature, moisture content and other physical properties of soil such as thermal capacity, coefficient of heat conductivity, and specific heat. the main objective of the present paper is to de...

arid and semi-arid lands cover around one-third of the world's terrestrial expanse and their widespread plantdistributions provide these areas with a high potential for sequestering carbon. vegetation management for developingshrub or tree species in arid and semi-arid regions is one inexpensive and multi-purpose approach for decreasing co2.this study assessed the potential of carbon sequestrat...

Water resources globally face unprecedented challenges, but these are at their greatest in the world’s arid and semi-arid regions. Recent IPCC estimates (Kundzewicz et al., 2007) state that between 1.4 and 2.1 billion people live in areas of water stress; those numbers are expected to increase significantly under the pressures of population growth and climate change. By definition, arid and sem...

New vegetation in barren areas offers possibilities for sequestering carbon in the soil. Arid and semi-arid areas (ASAs) are candidates for new vegetation. The possibility of agriculture in ASAs is reviewed, revealing the potential for cultivation by covering the surface with a layer of organic fibres. This layer collects more water from humidity in the air than does the uncovered mineral surfa...

the importance of groundwater as a source of water supply in arid, semi –arid areas in recent years due to the uncontrolled exploitation of groundwater have been doubled. uncontrolled exploitation has been caused a drop in the water table in many areas of the country, including this region. with replace methods of modern irrigation instead of traditional irrigation methods can prevent drop the ...

knowledge about low flow statistics is essential for effective water resource planning and management in ungauged orpoorly gauged catchment areas, especially in arid and semi-arid regions such as iran. we employed a data set of 20 riverflow time-series from the iranian central plateau river basin, iran to evaluate the low-flow series using several frequencyanalysis methods and compared the resu...

in arid and semi-arid rangelands, grazing as one of the natural or human induced processes has direct and indirect effects on structure and dynamics of plant community and ecosystems. a study was done to analyze the effects of grazing on plant species diversity and plant functional types‘ (pfts) diversity of arid and semi-arid rangelands. we analyzed plant richness and diversity data from 75 sa...

this study aims to assess the effect of grazing intensity on vegetation structure, soil nutrient concentrations and soil physical properties. the study was carried out in steppe rangelands of saveh, markazi province, iran. four sites with four grazing intensities including very high, high, moderate and non-grazed with the same ecological conditions were selected. to study various vegetation and...

Few studies have investigated the influence of water availability on plant population spatial patterns. We studied changes in the spatial patterns of Caragana stenophylla along a climatic drought gradient within the Inner Mongolian Plateau, China. We examined spatial patterns, seed density, "nurse effects" of shrubs on seedlings, transpiration rates and water use efficiency (WUE) of C. stenophy...

Abstract Desertification is one of the fundamental problems that threaten many arid and semi-arid areas. The formulation of the United Nation Convention to Combat Desertification (UNCCD), adopted in Paris, 1994 and ratified in 1996, with the active participation of Egypt, gave emphasis on combating the major threats to sustainability of dry lands. Recently, different models were developed to fo...