نتایج جستجو برای: desert areas

تعداد نتایج: 414951  

2014
F. Allag S. Bouharati M. Belmahdi R. Zegadi

The rapid expansion of deserts in recent decades as a result of human actions combined with climatic changes has highlighted the necessity to understand biological processes in arid environments. Whereas physical processes and the biology of flora and fauna have been relatively well studied in marginally used arid areas, knowledge of desert soil micro-organisms remains fragmentary. The objectiv...

2005
Camille A. Holmgren Jodi Norris Julio L. Betancourt

Late Quaternary histories of two North American desert biomesC4 grasslands and C3 shrublandsare poorly known despite their sensitivity and potential value in reconstructing summer rains and winter temperatures. Plant macrofossil assemblages from packrat midden series in the northern Chihuahuan Desert show that C4 grasses and annuals typical of desert grassland persisted near their present north...

2013
Mohamad Bakir

This paper attempts to describe the state of Rainwater Harvesting (RWH) techniques and the contributions of GIS and Remote Sensing (RS) technologies for RWH in The Syrian Desert (AL-Badia). Studies were conducted using physiographic factors of The Syrian Desert (the natural factors, the climatic factors, the pastoral cover, and animal wealth) for the applications of GIS and Remote sensing techn...

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2010
P Vítek H G M Edwards J Jehlicka C Ascaso A De los Ríos S Valea S E Jorge-Villar A F Davila J Wierzchos

The hyper-arid core of the Atacama Desert (Chile) is the driest place on Earth and is considered a close analogue to the extremely arid conditions on the surface of Mars. Microbial life is very rare in soils of this hyper-arid region, and autotrophic micro-organisms are virtually absent. Instead, photosynthetic micro-organisms have successfully colonized the interior of halite crusts, which are...

2007
Paul C. Johnson

A 60-year database of nitrate concentrations from more than 200 wells in and around Phoenix, Arizona, was studied using geographic information system tools. This information, augmented with land-use maps, ground water levels, and well construction details, was used to examine ground water nitrate concentrations and changes in concentration and their relationship to land use, land-use changes, a...

Journal: :Remote Sensing 2016
Frank-M. Göttsche Folke-Sören Olesen Isabel F. Trigo Annika Bork-Unkelbach Maria A. Martin

Since 2005, the Land Surface Analysis Satellite Application Facility (LSA SAF) operationally retrieves Land Surface Temperature (LST) for the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board Meteosat Second Generation (MSG). The high temporal resolution of the Meteosat satellites and their long term availability since 1977 make their data highly valuable for climate studies. In o...

Journal: :Journal of environmental sciences 2007
Qiu-yan Li Wen-zhi Zhao Hai-yan Fang

This study addresses the adaptation of Nitraria sphaerocarpa to blown sand at the edge of a desert oasis with regard to the aspects of soil seed banks, seedlings, and population. Horizontally, the total number of seeds per unit area decreased from the shrub canopy center to intershrub areas, and most seeds were found under shrub canopies. Vertically, the highest proportion of seeds was found at...

Journal: :محیط شناسی 0
امیر هوشنگ احسانی دانشیار گروه مهندسی طراحی محیط زیست، دانشکدۀ محیط زیست، دانشگاه تهران مرضیه فروتن دانشجوی دکتری، جغرافیا، دانشگاه کالگری کانادا

introduction morphological segmentation of land surface is commonly used for land surface allocation in management and environmental sciences. the first step in assigning a piece of land to a specific application is to divide it into homogeneous morphological segments. traditional field-based geomorphological mapping can be time consuming, costly, and challenging when large areas, particularly ...

Journal: :Journal of vector borne diseases 2005
S P Yadav R C Sharma Vinod Joshi

BACKGROUND & OBJECTIVES A longitudinal study on social determinants of malaria has been undertaken in different villages of Ramgarh PHC of Jaisalmer district, Rajasthan. The study aims to determine social determinants of malaria as applicable to existing cast groups of desert part of Rajasthan. METHODS Out of 940 households in five villages, 150 households of Rajput community (forward communi...

2006
M. L. Brooks J. R. Matchett

Fire has been historically infrequent in the Mojave Desert, and its increased prevalence caused by the invasion of non-native annual grasses is a major concern for land managers there. The most dramatic changes have occurred in middle elevation shrublands dominated by creosotebush (Larrea tridentata), Joshua tree (Yucca brevifolia), and/or blackbrush (Coleogyne ramossissima), where most of the ...

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