نتایج جستجو برای: desertification assessment
تعداد نتایج: 562493 فیلتر نتایج به سال:
one of the characters in iranian model of desertification potential assessment (imdpa) is soil. since soil is very important in the degradation of land, so some indices were determined for this character in order to evaluate desertification potential of arid, semi-arid and dry sub humid areas of iran. the indices included soil texture, deep gravel percentage, soil depth, and ec. to calibrate th...
one of the characteristics in iranian model of desertification potential assessment (imdpa) is vegetation. sincevegetation is very important factor in the degradation of land, so some indices were determined for this item in order toevaluate desertification potential of arid, semi arid and arid sub humid areas of iran. the indices included vegetationcondition, exploit and revegetation. to calib...
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 ...
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...
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 ...
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...
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...
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 ...
Extended abstract 1-Introduction Desertification means land degradation in the arid, semi-arid and dry sub-humid regions because of natural or anthropogenic factors. Desertification is accounted as the third most important global challenge after the crisis of water shortage and drought in the 21st century. Desertification is a problem for many countries, especially the developing countries. I...
Land degradation impacts on several critical environmental issues such as food security, diminishing quality and quantity of fresh water resources, preservation of natural resources, loss of biodiversity, and global climate change. Land degradation is responsible for soil erosion and can eventually lead to desertification. The International Convention to Combat Desertification (CCD) defines des...
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