نتایج جستجو برای: arid area

تعداد نتایج: 599002  

Overgrazing affects plant communities, and is a significant disturbance factor in arid and semi-arid regions. The immediate changes of plant communities after overgrazing in the disturbed arid ecosystems of Iran have been poorly studied. We recorded data from 100 random samples before and after overgrazing in the Golbahar plain located in the northeastern Iran to determine the changes in the pl...

Journal: Geopersia 2014

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: :international journal of environmental research 0
y. x. feng xinjiang institute of ecology and geography, chinese academy of sciences, urumqi 830011, china g.p. luo xinjiang institute of ecology and geography, chinese academy of sciences, urumqi 830011, china c.f. li xinjiang institute of ecology and geography, chinese academy of sciences, urumqi 830011, china l. dai xinjiang institute of ecology and geography, chinese academy of sciences, urumqi 830011, china e. chianese department of environmental science, university “parthenope” of naples, centro direzionale isola c4, 80143 napoli, italy

this study aims to quantify the impacts of land use changes on ecosystem service value during large scale land development, and to provide key information for both economic development and policy makers for eco-environmental protection. the study area locates in manas river watershed which is a typical land development region in northwest china. landsat mss/tm/etm+ images in 1976, 1989, 1999 an...

Journal: :بوم شناسی کشاورزی 0
سید حسین ثنایی نژاد علیرضا آستارایی مرجان قائمی

remote sensing techniques are known as very useful methods for studying land use management in arid and semi arid areas, where undeveloped soils are dominant. these techniques can be used for determining different environmental characteristics including soil and vegetations. in this study etm+ band ratios and principal component analysis (pca) were used for monitoring of vegetation cover and it...

Journal: :تحقیقات نظام سلامت 0
عباس آقاخانی دانشجوی دکتری، دانشکده عمران، دانشگاه صنعتی اصفهان، اصفهان، ایران. محسن سعدانی کارشناس ارشد، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان و مربی، دانشکده بهداشت، دانشگاه علوم پزشکی شهید صدوقی، یزد، ایران مریم فرجی کارشناس ارشد، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران. غلامرضا بنیادی نژاد کارشناس ارشد، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران.

background: iran is an arid country and has serious limitations in terms of water recourses. in arid and semi-arid regions this problem is more severe. industry is one of the primary water consumers in the country and appropriate determination of industry water demand is on the most important priorities that should be considered to save water consumption as well as determining the industry wate...

Journal: :international journal of environmental research 2012
y. x. feng g.p. luo c.f. li l. dai l. lu

this study aims to quantify the impacts of land use changes on ecosystem service value during large scale land development, and to provide key information for both economic development and policy makers for eco-environmental protection. the study area locates in manas river watershed which is a typical land development region in northwest china. landsat mss/tm/etm+ images in 1976, 1989, 1999 a...

2018
Andrea J. Roth-Monzón Andrés Alberto Mendoza-Hernández Oscar Flores-Villela

Current global changes are putting both biodiversity and the processes that depend on it at risk. This is especially true for semi-arid regions and the flagship groups that inhabit them, such as amphibians and reptiles. Semi-arid regions are often thought to have lower biodiversity and thus have been overlooked, resulting in the underestimation of their biological richness. Therefore, the aim o...

2017
Miguel A. Medina-Morales Oscar Soto-Cruz Juan C. Contreras-Esquivel Raúl Rodríguez-Herrera Heliodoro De la Garza-Toledo Cristóbal N. Aguilar

Agave is a good source of polysaccharides for the production of fermentable sugars as sustainable bioenergy feedstock solutions for semi-arid and arid lands. This plant grows in arid areas, which correspond to a large territory in northern Mexico. Having lignocellulose as the polysaccharide of interest, the information for the enzymatic saccharification of this kind of material is limited. Agav...

2002
Dallas Bash Yvette M. Villegas

This paper reports a practical application of digitally enhanced Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) data coupled with principal component analysis (PCA) and spectral angle mapping (SAM) techniques to assess changes in vegetation and land condition within the U.S. Army installation at Fort Bliss, Texas. Fort Bliss is located in a semi-arid desert environment wh...

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