نتایج جستجو برای: arid region in north

تعداد نتایج: 17040270  

Journal: :تحقیقات جغرافیایی 0
علیرضا تقیان دانشگاه اصفهان

abstract alluvial fans are the most striking phenomena o fluvial geomorphology . these forms are found in frount of mountains and pediments of arid and semiarid zones . alluvial fans are affected by climate changes and tectonics . occurring of tectonic events lead to reaction of alluvial fans . some of these reactions appear on dissection of alluvial fans and displacement of depocenters on allu...

Journal: :ecopersia 2015
behnaz attaeian behnoush farokhzadeh davoud akhzari mohammad mehdi artimani mahshid souri

soil alkalinity and salinity are serious problems in arid and semi-arid regions, and therefore monitoring of soil ph and electrical conductivity (ec) is necessary in any region. the present study aimed to properly interpolate soil ph and ec as soil quality indices in a semi-arid mountainous area with annual precipitation of 342.4 mm. the study area is the karimabad rangelands in hamadan provinc...

Journal: :geopersia 2014
jyoti sharma habib alimohammadian amavala bhattacharyya parminder ranhotra morteza djamali

palynological analyses from exposed palaeolacustrine deposits located at the flanks of damavand volcano, in the central alborzmountains in northern iran, provide a broad idea of the temporal variation of vegetation according to climate changes during a rangeof limited time intervals during the quaternary period. this research reveals that the regional vegetation of the study area had been asemi...

Journal: : 2021

On the basis of experimental garden Precaspian agrarian federal scientific center (Astrakhan region) in 2017 ... 2020, quality fruits apple varieties Renet Simirenko, Idared and Melba on rootstocks SK series (North Caucasus) selection North Caucasus Federal Scientific Center for Horticulture, Viticulture, Winemaking was studied comparison with combinations M (a total 27 graft-rootstock combinat...

Extended abstract 1- Introduction Water scarcity is currently one of the worldchr('39')s challenges, especially in arid and semi-arid regions; This is because population growth and rising living standards require more food and water. Therefore, excessive use of natural resources has led to the destruction of potential agricultural lands and natural resources. The final process is floods, dust...

Drought is one of the most destructive natural disasters in human societies that cause irreparable impacts on agriculture, environment, society and economics. So, awareness of occurrence of droughts can be effective in reducing losses. In this study, in order to modeling and forecasting drought severity in a 37 year time period (1971-2007) in 21 meteorological stations, located in the cold semi...

Journal: :مرتع و آبخیزداری 0
سید هدایت پروری اصل دانش آموخته کارشناسی ارشد رشته بیابان¬زدایی، دانشکده منابع طبیعی، دانشگاه زابل، ایران احمد پهلوانروی استادیار، دانشکده منابع طبیعی، دانشگاه زابل، ایران علیرضا مقدم نیا استادیار، دانشکده منابع طبیعی، دانشگاه زابل، ایران

desertification is the consequence of series of processes in which climate change and human activities are more important factors than others. arid and semi-arid areas have occupied most parts of iran. sistan region is one of arid areas of iran where wind erosion is an important factor of land degradation and soil deterioration. for classification of desertification intensity, several methods h...

Wind is one of the main causes of erosion and degradation of land in arid and semi-arid regions. In these areas, winds are more effective than other areas due to lack of vegetation cover. The purpose of this research is to use granulometric analyzes in desertification studies in Gonabad city,  To achieve this goal, after the preparation of geomorphological maps of the region, 14 sediment sample...

Journal: :Evolution; international journal of organic evolution 2013
John J Wiens Kenneth H Kozak Natalia Silva

Deserts occupy approximately 12% of the Earth's land surface, and are thought to have species poor but highly specialized biotas. However, few studies have examined the evolutionary origins of desert biotas and of diversity patterns along aridity gradients. Further, it is unclear if species occurring in more extreme conditions on a given niche axis (i.e., precipitation) are more specialized for...

Journal: :Remote Sensing 2014
Wenping Yu Mingguo Ma Xufeng Wang Liying Geng Junlei Tan Jinan Shi

This study presents preliminary results of the validation of the Moderate Resolution Imaging Spectroradiometer (MODIS) daily LST products (MOD/MYD11A1, Version 5) using longwave radiation ground measurements obtained at 12 stations in the North Arid and Semi-Arid Area Cooperative Experimental Observation Integrated Research program. In this evaluation process, the broadband emissivity at each s...

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