نتایج جستجو برای: arid region in north

تعداد نتایج: 17040270  

2017
Cuicui Jiao Guirui Yu Jianping Ge Xi Chen Chi Zhang Nianpeng He Zhi Chen Zhongmin Hu

To explore the importance of the Eurasian steppe region (EASR) in global carbon cycling, we analyzed the spatiotemporal dynamics of the aboveground net primary productivity (ANPP) of the entire EASR from 1982 to 2013. The ANPP in the EASR was estimated from the Integrated ANPPNDVI model, which is an empirical model developed based on field-observed ANPP and long-term normalized difference veget...

Journal: :journal of rangeland science 2013
gholamreza zehtabian hossein azarnivand hasan ahmadi saeideh kalantari

one of the influential tools concerning the rangeland and vegetation sciences isthe technology of remote sensing and satellite data. satellite data have played essentialroles in preparing the needed information for studying the vegetation. vegetation has beenwidely recognized as one of the best indicators for determining the land conditions. usingvegetation indices is one of the techniques of r...

Journal: :journal of rangeland science 2012
jalal barkhordari trahel vardanian

classifying remote sensing imageries to obtain reliable and accurate landuse/cover (luc) information still remains a challenge that depends on many factors suchas complexity of landscape especially in arid region. the aim of this paper is to extractreliable luc information from land sat imageries of the pishkouh watershed of centralarid region, iran. the classical maximum likelihood classifier ...

Extended abstract 1- Introduction A dust storm is one of the biggest serious environmental problems in the arid and semi-arid regions of the world, causing irreparable damages to farms, facilities, roads, traffic and transportation every year and respitory problems by contaminating the air. Due to the geographic location of Iran which is  in the arid and semi-arid belt of the world, the count...

ژورنال: :مجله تحقیقات دامپزشکی (journal of veterinary research) 2007
مهدی خلج صادق رهبری صدیقه نبیان حسن لدنی وحید عطارد

two hundred and ninty four engorged female ticks were collected from 4 different geographical regions for assessment of tick resistance against acaricide compounds.the 15-21 day- old larvae have been tested in accordance with fao recommended larvae packet test . resistant factor for each region was calculated by lc50 and lc99. minimum lc50 (0.008)and, maximum lc50 (0.024) for amitraz wer...

Journal: :desert 0
h. azarnivand associate professor, faculty of natural resources, university of tehran, karaj, iran m.a. zare chahouki associate professor, faculty of natural resources, university of tehran, karaj, iran h. joneidi assistant professort, university of kurdestan, sanandaj, iran

one of the characteristics in iranian model of desertification potential assessment (imdpa) is vegetation. sincevegetation is very important factor in the degradation of land, so some indices were determined for this item in order toevaluate desertification potential of arid, semi arid and arid sub humid areas of iran. the indices included vegetationcondition, exploit and revegetation. to calib...

Understanding weather zoning and knowing homogeneous climate regions are essential for land use and regional planning. The aim of this study was to compare three different geographical climate of Iran, the Caspian coastal, mountainous and arid interior of the provinces of Mazandaran, Semnan, Tehran, Qazvin, Qom, and Markazi. In order to do this study, climatic data of 56 synoptic and climatolog...

2012
K. H. Li

General Comments: This manuscript, “Atmospheric reactive nitrogen concentrations at ten sites with contrasting land use in an arid region of Central Asia”, is a good baseline assessment of the concentrations of nitrogenous species for an understudied region of the world, the arid Xinjiang region of China. This study will provide foundational information in understanding air quality over this re...

2008
Steven R. Archer Katharine I. Predick

Arid desert ecosystems of the western United States are particularly susceptible to climate change and climate variability. Plants and animals in this region live near their physiological limits for water and temperature stress. Slight changes in temperature or precipitation regimes or a change in the frequency and magnitude of extreme climatic events could therefore substantially alter the com...

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