نتایج جستجو برای: degradation indicators

تعداد نتایج: 258369  

2013
H Y Wang Z Y Li Z H Gao J J Wu C L Li

Land condition assessment is a basic prerequisite for finding the degradation of a territory, which might lead to desertification under climatic and human pressures. The temporal change in vegetation productivity is a key indicator of land degradation. In this paper, taking the Otindag Sandy Land as a case, the mean normalized difference vegetation index (NDVI_a), net primary production (NPP) a...

Journal: :Revista de biologia tropical 2006
A C Fonseca H K Dean J Cortés

Coral reef status was surveyed in three south Pacific coral reefs of Costa Rica, one in Caño Island and two in Golfo Dulce, and the density, richness and distribution of non-colonial macro borers (> 1 mm) was determined in dead and live coral fragments from these reefs. Based upon traditional indicators of degradation such as high particulate suspended matter and low live coral cover, the reefs...

2003
David I. Stern

1. Introduction The environmental Kuznets curve is a hypothesized relationship between various indicators of environmental degradation and income per capita. In the early stages of economic growth degradation and pollution increase, but beyond some level of income per capita (which will vary for different indicators) the trend reverses, so that at high-income levels economic growth leads to env...

Journal: :The British journal of radiology 2000
R Burgul F J Gilbert P E Undrill

In recent years, teleultrasound has emerged as a potentially effective method of provision of ultrasound services to remote areas of the community. Transmission of teleultrasound, however, requires a high degree of compression when utilizing the relatively low bandwidth ISDN connections available within the UK. The actual amount of compression occurring varies both with the connection and the i...

2013
Mirjam Pulleman Rachel Creamer Ute Hamer Johannes Helder Céline Pelosi Guenola Peres Michiel Rutgers

max 200 words) Soil biota are essential for many soil processes and functions, yet there is an increasing pressure on soil biodiversity and soil degradation remains a pertinent issue. Therefore, the sustainable management of soils requires soil monitoring, including biological indicators able to relate land use and management to soil functioning and ecosystem services. Since the 1990’s, biologi...

2001
P. S. André A. L. J. Teixeira J. L. Pinto J. F da Rocha

This paper reports a detailed experimental study of the wavelength conversion dynamics using cross-gain modulation in reflective semiconductor optical amplifiers. The effect of pump and probe powers on the operating performance in terms of signal to noise ratio was experimentally investigating. The variation of others performance indicators such as extinction ratio, timing jitter and eye openin...

Journal: :desert 2008
a.a. mehrabi gh. zehtabian n. rostami a. malekian

undoubtly, land degradation causes apparent decrease of natural resources potential which are highly linked to desertification. different countries and also international organization have realized a great number of projects to combat desertification. unfortunately these projects have not reach to their goals. the experiences shows that the reason of these unsuccessful works is lack of consider...

Journal: :مرتع و آبخیزداری 0
زهرا گیوئی اشرف کارشناس ارشد مدیریت مناطق بیابانی محمد علی حکیم زاده ااستادیار گروه مدیریت مناطق بیابانی، دانشکدة منابع طبیعی، دانشگاه یزد محمد زارع استادیار گروه مدیریت مناطق بیابانی، دانشکدة منابع طبیعی، دانشگاه یزد زهره ابراهیمی خوسفی کارشناس ارشد مدیریت مناطق بیابانی کاظم دشتکیان عضو هیئت علمی مرکز تحقیقات کشاورزی و منابع طبیعی یزد

desertification relates to the both the process and end state of drylands degradation. salinization and alkalinization are two indicators of soil degradation in arid and semi-arid regions. the main objectives of this research is monitoring of soil salinity using high spectral and spatial resolution of remote sensing to assess desertification in the marvast plain, yazd province. two images of te...

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