چکیده:
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 the soil character of the IMDPA, above mentioned indices were assessed in
Segzi Pediment as arid region. To do this, in first stage, map of the study area was prepared based on slope, land use and
geological maps. Scores of indices were recorded in different study units. At last, using the formula, SI= 4 a.b.c.d , final
score of soil indicator (SI) was determined in the study area based on IMDPA. In this model, desertification potential
classes are low, moderate, high and very high. The map showed that 1.5%, 20% and 78.5% of the study area are
considered as medium, high and very high desertification intensity classes, respectively. More over, there wasn't low class
based on vegetation character.
خلاصه ماشینی:
R. Abbasid a Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran b Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran c Professor, Islamic Azad University, Science and Research Branch , Tehran, Iran d Research instructor, Forest, Range Watershed Management Organization, Tehran, Iran Received: 4 February 2007; Received in revised form: 1 March 2008; Accepted: 1 June 2008 Abstract 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.
d , final score of soil indicator (SI) was determined in the study area based on IMDPA.
Introduction According to the definition given in the Convention to Combat Desertification taken by the United Nations (1994), desertification is any land degradation in arid, semi-arid and dry sub- humid areas, resulting from various factors, including climatic variations and human activities.
Therefore, evaluation of soil changes can be as a suitable indicator to assess desertification intensity.
This research focuses on soil indicator with Iranian Model of Desertification Potential Assessment (IMDPA).
Results and discussion The map of current desertification status caused by soil, prepared according to final score of soil indicator (Fig 1).
Table 2 shows the surface areas of each desertification classes caused by soil.
This leads to soil degradation and therefore it is not surprising a major part of the study area is in class four (very high) of desertification.