نتایج جستجو برای: percent vegetation cover

تعداد نتایج: 243442  

Ali Ashraf Jafari Hossein Arzani Mohammad Jafari Sedigheh Zare Kia Seyyed Akbar Javadi

This study aims to assess the effect of grazing intensity on vegetation structure, soil nutrient concentrations and soil physical properties. The study was carried out in steppe rangelands of Saveh, Markazi province, Iran. Four sites with four grazing intensities including very high, high, moderate and non-grazed with the same ecological conditions were selected. To study various vegetation and...

Journal: :اکو هیدرولوژی 0
مجید خزایی دانشجوی دکتری آبخیزداری دانشگاه هرمزگان احمد نوحه گر استاد دانشکدۀ محیط زیست دانشگاه تهران رسول مهدوی نجف آبادی عضو هیئت علمی آبخیزداری دانشگاه هرمزگان عبدالرسول تلوری سازمان جنگل‏ها و مراتع و آبخیزداری کشور

the vital need for river management is understood and predict of bank erosion processes. almost models will not be able to evaluate bank erosion,accurately. bstem model is the most usable model in many of river engineering projects in the world. necessary data for this model are related to driving and resisting forces controlled by hydraulic and geotechnical processes. these data include geomet...

Journal: :journal of rangeland science 2010
a. mirjalili

in this investigation, the effects of enclosure, restal delayed grazing andcontinued grazing treatments on the production rate and vegetation cover were studied.study area was sadrabad pasture. after selecting three bands (1+1+1=3 hectare area) asthree treatments in the restricted and non restricted area, they were transected to threetransects. then plots (1×2m2 ) were selected to measure the p...

Journal: :ISPRS Int. J. Geo-Information 2012
Ronald C. Estoque Ria S. Estoque Yuji Murayama

Analysis of spatial and temporal changes of vegetation cover using remote sensing (RS) technology, in conjunction with Geographic Information Systems (GIS), is becoming increasingly important in environmental conservation. The objective of this study was to use RS data and GIS techniques to assess the vegetation cover in 1989 and 2009, in the barangays (smallest administrative units) of the cit...

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...

2003
Tommy L. Coleman James H. Miller

The objective of this study was to investigate the regression relations between vegetation indices derived from remotely-sensed data of single and mixed forest regeneration plots. Loblolly pine (Pinos faeda L.J seedlings, sweelgum (Liquidambar sfyraciflua L.) seedlings and broomsedge (Andropogon virginiws L.) grass were arranged in a factorial combination addition series experiment and replicat...

Journal: :Remote Sensing 2014
Xiaohui Yang Xulin Guo

Spectral vegetation indices have been the primary resources for characterizing grassland vegetation based on remotely sensed data. However, the use of spectral indices for vegetation characterization in grasslands has been challenged by the confounding effects from external factors, such as soil properties, dead materials, and shadowing of vegetation canopies. Dead materials refer to the dead c...

Biodiversity is one of the important concepts in ecology and vegetation management, and plays an important role in the health, production, and evaluation of ecosystems. Species diversity is a major part of biodiversity and one of the most important parameters of ecosystem changes. In this research, the data of the rangeland evaluation different climate zones of Isfahan province were used in fiv...

2014
Y. Wang M. L. Roderick Y. Shen F. Sun

Terrestrial vegetation dynamics are closely influenced by both climate and by both climate and by land use and/or land cover change (LULCC) caused by human activities. Both can change over time in a monotonic way and it can be difficult to separate the effects of climate change from LULCC on vegetation. Here we attempt to attribute trends in the fractional green vegetation cover to climate vari...

2017
Dongwook W. Ko Dasom Kim Amartuvshin Narantsetseg Sinkyu Kang

Background: Monitoring terrestrial vegetation cover condition is important to evaluate its current condition and to identify potential vulnerabilities. Due to simplicity and low cost, point intercept method has been widely used in evaluating grassland surface and quantifying cover conditions. Field-based digital photography method is gaining popularity for the purpose of cover estimate, as it c...

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