نتایج جستجو برای: dry land

تعداد نتایج: 206267  

2005
RAYMOND W. ARRITT

Variations of dry deposition velocity for S02 due to terrain-forced mesoscale circulations have been explored for northeast Colorado and south Florida. A mesoscale numerical model was used to obtain the wind and turbulence data needed to calculate the deposition velocities. Computations were performed both with and without consideration of observed land use characteristics. The results indicate...

Journal: :پژوهش های حبوبات ایران 0
مجنون حسینی مجنون حسینی حمزه ئی حمزه ئی

in order to evaluate a better sowing date of chickpea cultivars in dry land conditions, a factorial experiment in randomized complete block design with four replications was carried out at research station of bahar (hamadan province) during 2005-2006 cropping season. two planting time included winter and spring and four chickpea cultivars (cvs.) including one local (check) and three improved cv...

Soil erosion and sediment yield from watersheds confine sustainable use of land resources and is supposed as one of the most critical environmental issues. Prediction of storm wise soil erosion and sediment yield is very important, especially in arid and semiarid regions due to small number of events and high intensity of rainfall. Evaluation of soil erosion by existing models is needed as an i...

Journal: :مرتع و آبخیزداری 0
حشمت اله آقارضی عضو هیئت علمی مرکز تحقیقات کشاورزی و منابع طبیعی استان مرکزی مهدی مردیان دانشجوی دکتری آبخیزداری دانشگاه علوم کشاورزی و منابع طبیعی ساری علی اکبر داوودی راد دانشجوی دکتری آبخیزداری دانشگاه تربیت مدرس و عضو هیئت علمی مرکز تحقیقات کشاورزی و منابع طبیعی استان مرکزی داوود نیک کامی دانشیار پژوهشکدة حفاظت خاک و آبخیزداری

land use optimization using linear programing is a method in watershed management for access to production sustainability and decreasing of soil erosion. the sensitivity analysis of the model can with investigation of results influence form changes in input parameters, lead to decrease the uncertainty in decision-making of management programs. so in this research, linear programming model using...

Journal: Desert 2015

The objective of this research was to determine the best model and compare performances in terms of producing landuse maps from six supervised classification algorithms. As a result, different algorithms such as the minimum distance ofmean (MDM), Mahalanobis distance (MD), maximum likelihood (ML), artificial neural network (ANN), spectral anglemapper (SAM), and support vector machine (SVM) were...

2007
A. Kelarestaghi H. Ahmadi M. Jafari

Land use change may influence many natural phenomena and ecological processes, including runoff, soil erosion, sedimentation and soil conditions. Decreasing of forest area in the North of Iran is one of the critical problems in recent years. The aims of this study are to detect land use changes between 1967 to 2002 using satellite images of Land Sat 7 ETM (2002), aerial photos and digital topog...

2012
Fred Nelson

The land management practices of pastoralist Maasai communities have a major bearing on landscapes and wildlife habitats in northern Tanzania and play a key role in maintaining habitat for one of the world's most spectacular assemblages of terrestrial large mammals. Pastoralists manage lands according to locally devised rules designed to manage and conserve key resources such as pastures and wa...

Journal: :international journal of agricultural management and development 2016
khadijeh abolfathi marzieh alikhah-asl mohammad rezvani mohammad namdar

the growing population and increasing socio-economic necessitiescreates a pressure on land use/land cover. nowadays, land use change detection using remote sensing data provides quantitative and timely information for management and evaluation of natural resources. this study investigates the land use changes in part of hableh rood watershed of iran using landsat 7 and 8 (sensor etm+ and oli) i...

2015
Emmanuel Quansah Matthias Mauder Ahmed A Balogun Leonard K Amekudzi Luitpold Hingerl Jan Bliefernicht Harald Kunstmann

BACKGROUND The terrestrial land surface in West Africa is made up of several types of savanna ecosystems differing in land use changes which modulate gas exchanges between their vegetation and the overlying atmosphere. This study compares diurnal and seasonal estimates of CO2 fluxes from three contrasting ecosystems, a grassland, a mixture of fallow and cropland, and nature reserve in the Sudan...

Journal: Desert 2006
A. Kelarestaghi, H. Ahmadi M. Jafari

Land use change may influence many natural phenomena and ecological processes, including runoff, soil erosion, sedimentation and soil conditions. Decreasing of forest area in the North of Iran is one of the critical problems in recent years. The aims of this study are to detect land use changes between 1967 to 2002 using satellite images of Land Sat 7 ETM+ (2002), aerial photos and digital topo...

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