نتایج جستجو برای: 4 criteria were selected including vegetation cover

تعداد نتایج: 4984083  

Journal: :محیط شناسی 0
نرگس حاج کاظمیها دانشجوی دکتری علوم محیط زیست، دانشکدۀ محیط زیست و انرژی، دانشگاه آزاد، واحد علوم و تحقیقات تهران، محمود شریعت استاد، دانشکدۀ محیط زیست و انرژی، دانشگاه آزاد، واحد علوم و تحقیقات تهران مسعود منوری استادیار، دانشکدۀ محیط زیست و انرژی، دانشگاه آزاد، واحد علوم و تحقیقات تهران محمد عطایی استاد، دانشکدۀ مهندسی معدن، دانشگاه صنعتی شاهرود

introduction development of natural resources and mining activities are prerequisite for economic and industrial growth in many countries. in many cases, such mining areas lie within residential or agricultural lands or natural habitats intensifying the contradiction between land use and environmental protection. different components of mining activities including exploration, extraction and pr...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده علوم تربیتی و روانشناسی 1388

on- the-job training on of the most effective tools for managers to cope with the changing organizational environment. it grantess suitable services to customers, particularly in public service enterprises. if such training os goal oriented, planned systematically, and tailored to the employees, job content, then not only it could increase employees and organizational performance, but also it c...

ژورنال: علوم آب و خاک 2007
احمد جلالیان, , حسین خادمی, , مریم یوسفی فرد, ,

Improper use of natural resources, especially soil, causes its degradation and severe soil erosion. Water erosion is an important factor causing soil degradation. Land use change of pasture would result in severe soil erosion mainly due to the reduction of vegetation cover and also surface soil disturbance. The objectives of this study were to estimate the amount of sediment, runoff and nutrien...

Journal: :آب و خاک 0
سلیمان پور سلیمان پور صوفی صوفی احمدی احمدی

abstract gully erosion is a kind of water erosion that has high priority in fars province due to sediment production and enormous damages to land, roads and infrastructures. in this study, 15 gullies were selected and their morphometric characteristics, such as catchment area, soil, cover vegetation and climate were measured. in order to determine influential factors on the sediment production ...

Journal: :desert 2010
hosein azarnivand hamed joneidi jafari sh. nikoo mohamad zare chahouki a. malekian

abstract the objective of current research is to investigate distribution patterns of vegetation types and its relation with environmental factors in southern margin of haj aligholi kavir of damghan. three vegetation types including halecnemum strobilaceum, sedlitzia rosmarinus and artemisia sieberi were studied in marginal arid regions and uplands of the study area. firstly, geographic locatio...

Journal: :محیط شناسی 0
سید حامد میرکریمی استادیار دانشگاه علوم کشاورزی و منابع طبیعی گرگان سپیده سعیدی دانشجوی دکتری ارزیابی و آمایش محیط زیست، دانشگاه علوم کشاورزی و منابع طبیعی گرگان مرجان محمد زاده استادیار دانشگاه علوم کشاورزی و منابع طبیعی گرگان عبدالرسول سلمان ماهینی دانشیار دانشگاه علوم کشاورزی و منابع طبیعی گرگان

introduction conservation and management of landscapes and beautiful sceneries is one of the necessities of establishing and maintaining the protected areas. analysis of landscape visual quality has an important place in landscape planning and designing. in this way, reviewing effective criteria and discovering the simple patterns which affect the landscapes is the most important step of modeli...

Journal: :Environmental management 2006
Steven S Seefeldt D Terrance Booth

Methods that are more cost-effective and objective are needed to detect important vegetation change within acceptable error rates. The objective of this research was to compare visual estimation to three new methods for determining vegetation cover in the sagebrush steppe. Fourteen management units at the US Sheep Experiment Station were identified for study. In each unit, 20 data collection po...

Introduction: More than 168 countries face the phenomenon of land degradation and desertification. Land use changing and more exploitation of nature's potential in arid and semiarid ecosystems over the past three decades have increased the trend of desertification phenomena in these ecosystems. Deserts are dynamic ecosystems that are constantly evolving. Deserts are dynamic ecosystems that are ...

Mohammad rahimi Mohammadkia kianian Neda soleiman dehkordi Seyed Hassan kaboli Shima nikoo Zahra bayat,

Desertification could be traced back to one or many factors. Thus, to cope with such a phenomenon, there exists a need for a profound understanding of the processes and the causes. The study area of the current paper is the extent of Shahrekord’s Marghzar as an important case amongst the important ones of the province. In order to evaluate the roots of desertification in the area, the Iranian m...

Fire affects vegetation and changes plant succession. In this paper, the vegetation of Sirachal Research Station, which burned in the summer of 2014, was studied and compared with the unburnt areas, based on biodiversity indices. The research was implemented as a factorial experiment in a completely randomized design. First, on the basis of physiognomy, the area was divided into three parts: sh...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید