Assessment and Mapping desertiication in the northern part o Khorasan Province.

The recent rapid increase in human population and the evolutions over the past two centuries has raised concerns that humans are beginning to overpopulate the Earth, and that the planet may not be able to sustain present or larger numbers o inhabitants and be orced to deal seriously with his environment. His battle with nature changed rom the traditional mode to a new orm o war with some kind o the tools and implements o war by emerging new energies. With a promotion in advance technology and improve living conditions, human population growth was as the most winning tactic o this war range. Thus inappropriate use over the years these ecosystems can decline the ecosystem energy and desertiication process is quickly expanding in the world. Expansion characteristics o desert areas is one o the main challenges o arid and semi arid regions that threat the world including our country. UN announced that the desertiication challenge is one o the three main challenges in the 37 major global challenges o the world in the twentyirst century. Result o studies shows that currently (1389) 78 percent (13,158.2 square kilometers) o the studied area are at risk o desertiication and aected by dierent desertiication processes. Only a level equivalent to 9.3 percent (1,572.1 square kilometers) o the total area is without any eects o desertiication. They are apparently are covered by orest or pasture with good coverage or areas prone to agriculture. A total o about 12.7 percent (2,131.0 square kilometers) o land are unsuitable component area (natural deserts) o arming with very low cover including the hills east Kopeh Dagh mountains (in the northern city o Bojnourd), salty land o south city o Esarayen and salty land or lowing sand o Jajarm city. The most exposed area o desert area with 92.3 percent o the city, most non-desert areas with vast extent o 15.3 percent o the city and most areas o vast natural wilderness area o 28.2 percent,have been on Esarayen city, Bojnourd and Jajarm respectively. Desertiication in the region, thus developing the our main phenomena (vegetation degradation, water erosion, wind erosion, soil secondary salinity) and their combined eects which are associated with human economic activity. Desertiication phenomenon is not observed in all the studied area. There are still care or using the land, because o the optimum crop water, appropriate user technology o agricultural produce, construction o gardens, the phenomenon, orested areas and grazed pastures Key words: Desertiication,Advance technology,desertiication challenge, desertiication process, characteristics o desert, natural deserts, vegetation degradation, water erosion, wind erosion, soil secondary salinity non-desert