نتایج جستجو برای: vegetation cover

تعداد نتایج: 148562  

Journal: Desert 2010
a. malekian hamed Joneidi Jafari Hosein Azarnivand mohamad Zare Chahouki sh. nikoo

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 locat...

Journal: Desert 2009
A. Tavili J. Farzadmehr M. Rostampour m.a Zare Chahouki

Abstract This paper presents a quantitative account of vegetation–environmental factor relationships in arid rangelands. Vegetation cover was recorded using Braun-Blanquet combined abundance-cover scale in each quadrat. Within each quadrat, one profile was dug and soil samples being taken at 0-20cm and 20-100cm depths. Under study physical-chemical characteristics included texture, lime, orga...

Journal: :Journal of environmental management 2012
Christopher M Gough Hunter L Elliott

Residential abandonment is on the rise in many urban areas, with unknown implications for ecosystem structure and function on land slated for partial or full restoration to native habitat. Partial decoupling of human and natural systems could reduce disturbance (e.g., trampling, recreational traffic) and modify vegetation structure in a way that alters soil carbon storage, an ecosystem function...

2011
THOMAS PANAGOPOULOS VERA FERREIRA JORGE JESUS

Soil erosion risk assessment at the watershed of Alqueva is urgently needed to conserve water resources and prevent the accelerated dam siltation. The variation of soil properties is one of the most important reasons for the spatial variability of vegetation cover and erosion. In order to achieve more and better management of rangelands around the largest reservoir of Europe, it is essential to...

2012
Kathryn Sheffield Elizabeth Morse-McNabb

This study aimed to develop a method for assessing changes in vegetation greenness and land cover over time at both landscape scales and for individual land parcels. It is hoped that an improved understanding of land cover history will increase understanding of soil condition, and linkages between soil health and productive capacity in Victorian agricultural landscapes. Gradual changes and diff...

2010
Soe W. Myint Anthony Brazel Gregory Okin Alexander Buyantuyev

The goal of this study is to improve our understanding of the interactive function of impervious and vegetation covers at different levels of the local and intra-urban spatial scales in relation to air temperatures in an urban environment. A multiple regression model was developed using impervious and vegetation fractions at different scales to predict maximum air temperature for the entire Pho...

1998
Rick L. Lawrence William J. Ripple

Spectral vegetation indices have been used extensively INTRODUCTION to predict ecological variables, such as percent vegetation On 18 May 1980, Mount St. Helens in the State of cover, above-ground biomass, and leaf-area index. We exWashington erupted with catastrophic, landscape-scale amined the use of various vegetation indices and multiple effects (Lipman and Mullineaux, 1981). In a mere 10 l...

2001
Francesca Pozzi Christopher Small

The objective of this study is to investigate the consistency of “suburban” population densities and land covers. We analyzed population density, extracted from the census, and vegetation abundance, derived from Landsat imagery, taking six cities in the U.S.A. as contrasting examples. Combining population density and areal vegetation abundance estimates yields univariate and bivariate distribut...

Journal: :Remote Sensing 2016
Olena Dubovyk Tobias Landmann Andreas J. Dietz Gunter Menz

Currently there is a lack of quantitative information regarding the driving factors of vegetation dynamics in post-Soviet Central Asia. Insufficient knowledge also exists concerning vegetation variability across sub-humid to arid climatic gradients as well as vegetation response to different land uses, from natural rangelands to intensively irrigated croplands. In this study, we analyzed the en...

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...

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