چکیده:
This study used quantifying factors affecting desertification based on the Iranian model of desertification potential assessment (IMDPA) to assess the current status of desertification in Bordekhun region, Iran. Bordekhun region has an area of 214.11 km2 and is located near the city of Daiyer in Boushehr province. First, a working unit map of the region was selected as the basic map for evaluation of factors and indices of interest. Regional conditions for the five criteria of
climate, wind erosion, water, soil, and vegetation were calculated as essential for the study of desertification intensity. The scores for the indices were determined using IMDPA; for each index, a map was prepared employing the calculated weighting. A qualitative map of the criterion was obtained using the geometric mean of indices related to each criterion. A map of current desertification potential was then created for the study area by combining the layers produced for each criterion, determining their geometrical means, and classifying the resultant map. Analysis of the study criteria showed that climate was rated high with a quantitative value of 3.15, wind erosion was high with a value of 2.87, water was medium with a value of 1.77, soil was high with a value of 2.66, and vegetation was medium with a value of 2.37. The results showed that of the total area, 49.12% is classified in the high desertification class, 48.9% is in the moderate class
and about 0.99% is not classified. The quantitative value of desertification intensity on the basis of the five criteria for the entire study area was desertification map (DM) = 1.55, which is indicative of the average desertification intensity in the region. The study area is located such that it has the potential for severe desertification. Climate was found to be the dominant criterion and plays an important role in desertification.
خلاصه ماشینی:
Evaluation of Current Desertification Status Based on IMDPA with Emphasis on Climate, Wind Erosion, Water, Soil and Vegetation: Case Study of Bordekhun Region of Boushehr A.
Bahreinia* a Faculty of Natural Resources, University of Zabol, Zabol, Iran Received: 9 April 2012; Received in revised form: 7 April 2013; Accepted: 12 May 2013 Abstract This study used quantifying factors affecting desertification based on the Iranian model of desertification potential assessment (IMDPA) to assess the current status of desertification in Bordekhun region, Iran.
Regional conditions for the five criteria of climate, wind erosion, water, soil, and vegetation were calculated as essential for the study of desertification intensity.
Amap of current desertification potential was then created for the study area by combining the layers produced for each criterion, determining their geometrical means, and classifying the resultant map.
A widely accepted definition of desertification is land degradation in arid, semi-arid, and sub-humid areas resulting from factors including climatic variation and human activity (Reynolds and Stafford-Smith, 2002; UNCCD, 1994).
IMDPA2 is a comprehensive desertification model that was developed by the Faculty of Natural Resources at the University of Tehran in a project entitled Determination of Methodology of Desertification Criteria and Indices in Arid and Semi-Arid Regions of Iran (Ahmadi, 2004).
IMDPA recognizes the five criteria of climate, wind erosion, water, soil and vegetation to be essential to the study of desertification.
7. Map of current desertification status caused by IMDPA Model Analysis of the criteria in Bordekhun region showed that climate, with a weighted average of 3.