نتایج جستجو برای: deforestation and desertification

تعداد نتایج: 16827997  

Journal: Desert 2017
M. Ownagh S.A. Arami

About 80 percent of Iran is arid and semi-arid and about 35 percent of this area is susceptible to desertification hazard. Therefore desertification assessment and identification of the most important criteria for the assessment of risk and a basis for development of management plans is essential. This research was conducted in the semi-arid region of Agh-Band in the Golestan province, Iran wit...

Journal: :desert 2013
h. ahmadi h. azarnivand m.r. ekhtesasei m. tazeh

there have been different indices identified for desertification. among these is technogenic desertification index which seems much more efficient. in this study, some of technogenic desertification indices were studied and evaluated. first land use maps of the region were taken from irs-pan satellite image and aerial photos analysis. after evaluating the area of different uses, lands that had ...

Journal: :Ecology letters 2009
Fernando T Maestre Matthew A Bowker María D Puche M Belén Hinojosa Isabel Martínez Pablo García-Palacios Andrea P Castillo Santiago Soliveres Arántzazu L Luzuriaga Ana M Sánchez José A Carreira Antonio Gallardo Adrián Escudero

The worldwide phenomenon of shrub encroachment in grass-dominated dryland ecosystems is commonly associated with desertification. Studies of the purported desertification effects associated with shrub encroachment are often restricted to relatively few study areas, and document a narrow range of possible impacts upon biota and ecosystem processes. We conducted a study in degraded Mediterranean ...

2008
Luca Montanarella Gergely Tóth

A common misunderstanding is that desertification is linked to the presence of deserts. The truth is that desertification can and does occur far from any climatic desert, as the presence or absence of a nearby desert has no direct relation to desertification. Desertification is the result of human induced land degradation which can be accelerated under severe drought conditions, and can occur u...

2013
Kazem Rangzan

Desertification is the reduction of ecologic and biologic on the earth surface, which might happen naturally or unnaturally (human). In this research, the TM and ETM images were used to study changes occurred in sand dunes during last 11 years and for determining the type of clay minerals. For evaluation of changes, maximum likelihood image classification and LMM, methods are carried out. Accor...

Journal: :desert 2013
a. pahlavanravi f. bahreini

this study used quantifying factors affecting desertification based on the iranian model of desertification potentialassessment (imdpa) to assess the current status of desertification in bordekhun region, iran. bordekhun region has anarea of 214.11 km2 and is located near the city of daiyer in boushehr province. first, a working unit map of the regionwas selected as the basic map for evaluation...

Land degradation in arid and semi-arid regions caused by climate change and human activities makes it more susceptible to desertification. The aim of this research is assessing the intensity of desertification in Roudab plain of Sabzevar city using IMDPA model. So two criteria of climate and water as the main criteria affecting desertification process were considered based on field observations...

2000
Wang Quan

Arid and semi-arid areas occupy one third of the total area of the world. This vast region is rich in natural resources. In recent times, desertification has become a world-wide phenomenon, due to human activities. China also suffers from this problem. Desertification is especially severe in the southeastern part of the arid and semi-arid region of the country. In this paper, the use of remote ...

2016
Emanuele Calabrò Salvatore Magazù

Background: This study investigates the connection between annual global solar radiation and ground albedo solar radiation due to desertification in line with previous research on the correlation between climatic changes and desertification. Methods: A simulation study was performed using an algorithm formulated by the authors and the typical albedo coefficient values of forested ground, green ...

2008

Germany has made the United Nations Convention to Combat Desertification (UNCCD) since its creation an instrument of choice for its policy to combat desertification and drought and for sustainable management of land. More then ten years after the Convention has entered into force in 1996, Germany continues to view it as a key reference point and strategic instrument of its development cooperation.

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