نتایج جستجو برای: land desertification

تعداد نتایج: 119172  

Investigation of desertification trend needs an understanding phenomena creating changes singly or action and reaction together in the manner that these changes end up in land degradation and desertification. In the investigation of pedological criterion affecting on land degradation in alluvial fans, first, maps of slope classes, land use and geology were created, then a map of units was found...

2012
YinPing CHEN YuQiang LI Tala AWADA JuanJuan HAN YongQing LUO

Horqin Sandy Land is a fragile, seriously desertified region located in Inner Mongolia of China. Overgrazing is one of the primary drivers of desertification in this region. We investigated whether the establishment of grazing exclosures in areas with active sand dunes enhances soil carbon (C) sequestration and benefits soil recovery. The results showed that soil organic C storage was 1.4, 1.9,...

2006
Sabine Chabrillat Hermann Kaufmann Paula Escribano Alicia Palacios-Orueta

The overall goal of this study is to develop remote sensing desertification indicators for drylands, in particular using the capabilities of imaging spectroscopy (hyperspectral imagery) to derive soil and vegetation specific properties linked to land degradation status. For this purpose, a hyperspectral (field and remote sensing) monitoring program was established in the Natural Park Cabo de Ga...

Introduction: Desertification refers to the decreased biological potentials in the ecosystem of hyper-arid, arid, semi-arid, and humid semi-arid regions because of climate change and human activities. The phenomenon occurs due to a combination of direct and indirect factors whose intensity varies according to time and place, making the scientific, replicable, and systematic evaluation of desert...

Victor R. Squires

The UNCCD has been ratified by over 190 countries. It is the attempt by nations, both rich and poor to control the scourge of desertification. The definition of which is “land degradation in arid, semiarid, and dry subhumid areas resulting from various factors, including climatic variations and human activities. It is now widely accepted that desertification is not the relentless advance of des...

Journal: :desert 0
m. karimpour reihan associate professor, international desert research center, university of tehran, tehran, iran s. feiznia professor, faculty of natural resources, university of tehran, karaj, iran a. salehpour jam ph.d. student, faculty of natural resources, university of tehran, karaj, iran m.k. kianian academic staff, university of semnan, semnan, iran

investigation of desertification trend needs understanding of phenomena creating changes singly or action and reaction together in the manner that these changes were ended up in land degradation. in investigation of pedological criterion onland degradation in quaternary rock units, first, a part of the rude-shoor watershed area was selected. after distinguishing target area, maps of slope class...

Journal: :desert 2013
m. karimpour reihan s. feiznia a. salehpour jam m.k. kianian

investigation of desertification trend needs understanding of phenomena creating changes singly or action and reaction together in the manner that these changes were ended up in land degradation. in investigation of pedological criterion onland degradation in quaternary rock units, first, a part of the rude-shoor watershed area was selected. after distinguishing target area, maps of slope class...

Journal: :Environmental management 2004
Rattan Lal

Drylands occupy 6.15 billion hectares (Bha) or 47.2% of the world's land area. Of this, 3.5 to 4.0 Bha (57%-65%) are either desertified or prone to desertification. Despite the low soil organic carbon (SOC) concentration, total SOC pool of soils of the drylands is 241 Pg (1 Pg = petagram = 10(15)g = 1 billion metric ton) or 15.5% of the world's total of 1550 Pg to 1-meter depth. Desertification...

Journal: :desert 2011
n. shakerian gh.r. zehtabian h. azarnivand h. khosravi

desertification refers to land degradation phenomenon in arid, semi-arid and dry sub-humid areas, resulting from various factors including climate variation and human activities. for evaluation and mapping of desertification many research have been conducted leading to regional and local models. in this research, among different existing methods imdpa was selected and desertification intensity ...

Journal: :Int. J. Applied Earth Observation and Geoinformation 2010
Jay Gao Yansui Liu

Tongyu County in Northeast China is highly prone to land degradation due to its fragile physical settings characterized by a flat topography, a semi-arid climate, and a shallow groundwater table. This study aims to determine the causes of land degradation through detecting the long-term trend of land cover changes. Degraded lands were mapped from satellite images recorded in 1992 and 2002. Thes...

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