نتایج جستجو برای: especially in arid and semiarid regions
تعداد نتایج: 21755242 فیلتر نتایج به سال:
improved pasture establishment in plants, especially in arid and semi-arid is very important application of biological fertilizers in pasture can be considered as a useful approach. that is one of the sources of the symbiotic fungus.. the purpose of the present study was to investigate the possibility of enhancing seedling establishment and growth rate of bromus kopetdaghensis under natural hab...
We analyzed potential land degradation processes in semiarid regions worldwide using long time series of remote sensing images and the Normalized Difference Vegetation Index (NDVI) for the period 1981 to 2011. The objectives of the study were to identify semiarid regions showing a marked decrease in potential vegetation activity, indicative of the occurrence of land degradation processes, and t...
The Chilean sclerophyllous matorral is a Mediterranean semiarid ecosystem affected by erosion, with low soil fertility, and limited by nitrogen. However, limitation of resources is even more severe for desert soils such as from the Atacama Desert, one of the most extreme arid deserts on Earth. Topsoil organic matter, nitrogen and moisture content were significantly higher in the semiarid soil c...
evaporation is one of the main parameters for the optimum operation of reservoirs, design of irrigation systems and scientific management of water resources. accurate estimation of the water evaporation level is crucial in any region especially in arid and semiarid regions. in this study, the feasibility of simulation of pan evaporation in maraghe station using the multiple regression models we...
abstract sensitive and precise voltammetric methods for the determination of trace amounts of furaldehydes, mainly as furfural (f) and 5-hydroxymethyl-2-furaldehyde (hmf), in waste waters and other matrices is described. determination of total furaldehyde at < ?g g-1 levels in alkaline buffered aqueous media was individually investigated. by the use of ordinary swv and adsorptive square wave ...
The global warming due to increased greenhouse gas concentrations, especially carbon dioxide has led to severe climate change over the past decade. This has aggravated the destruction of natural resources, soil and water, especially in arid and semi-arid regions. One of the most important tools for adaptation or correction of the consequences of this crisis is the carbon sequestration using nat...
Soil salinity is a major abiotic stress adversely affecting plant growth and crop production worldwide. Increased salinization of arable land is expected to have destructive universal effects, resulting in 30 % land loss within the next 25 years and up to 50 % by the middle of twenty-first century (Porcel et al. 2012; Kapoor et al. 2013; Abdel Latef and Chaoxing 2014). The term ‘‘salinity’’ ref...
It has been suggested that, unless a major effort is made, the atmospheric concentration of carbon dioxide may rise above four times the pre-industrial level in a few centuries. Here we use a coupled atmosphere-ocean-land model to explore the response of the global water cycle to such a large increase in carbon dioxide, focusing on river discharge and soil moisture. Our results suggest that wat...
Soil erosion is undoubtedly one of the most important problems in natural areas of Iran and has destructive effects on different ecosystems. Considering that calculation of the sediment rate in sediment stations and direct measurements of erosion process is costly and difficult, it is critical to find ways to accurately estimate the amount of sediment yield in catchments especially in arid and ...
عنوان: بررسی اوضاع فرهنگی گیلان (از انقلاب مشروطیت تا به قدرت رسیدن رضا شاه ) نویسنده: افضل افشاری سال :90-1389 استاد راهنما: دکتر ابوطالب سلطانیان استاد راهنما: دکتر حسن کهنسال واجارگاه چکیده: این پژوهش می کوشد اوضاع فرهنگی گیلان را از دور? مشروطیت تا ظهور رضا خان بررسی نماید و کم و کیف آن را آشکار سازد. انقلاب مشروطیت دو دستاورد مهم فرهنگی را در پی داشت؛ یکی انتشار گسترد? مطبوعات د...
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