International Symposium on
Drylands Ecology and Human Security
Introduction of Iranian Model of Desertification Potential Assessment to Monitoring and Assessment of Land Degradation:
Hassan Ahmadi* & Ali Akbar Nazari Samani
Faculty of Natural Resources, University of Tehran, Iran
Today since of human activities and his interventions on natural resources, especially in arid, semi arid and humid regions, the meaning of desert was changed and caused to create new terms such as: Desertification and Dedesertification. To evaluate desertification potential in Iran nine indicators including: Climate, Geology, Geomorphology, soil, vegetation, agriculture, erosion (wind and water), socio-economic and technogenic were considered as complex in Iranian Model of Desertification Potential Assessment (IMDPA). Each above-mentioned indicator consists of some quantitative indices (35 in total) and the score of each index was drawn based on various measurable parameters. To the final score of IMDPA was figured out through geometric mean of all nine indicators as following equation:
Finally, four classes including: Low (1), moderate (2), high (3) and very high (4) were consider to assess the desertification potential of each land use (rangeland, dry farming, and irrigated farming).
The Northern Hableh-rood basin was chosen as a typical semi arid region in Iran to calibrate reliability assessment of this method and indicators. A Terrain Mapping Units (TMU) was extracted through overlaying of landuse and slope as well as geology maps in GIS and in each TMU all of mentioned indicators and corresponding indices were evaluated and scored. Results indicated that among different factors, water erosion and technogenic had the most and least effects on desertification process respectively. In rangeland, the water erosion was the most effective factor and in term of this indicator 42 percent of the basin area laid in class 4 (very high), while in agricultural lands socio-economics get the high score on desertification. Among socio-economic indices, poverty and relay on land had a remarkable influence on desertification. According to results, it can be concluded that IMDPA has high adoptability to assess desertification in semi arid and sub humid regions of Iran. So it is proposed to assess this model in other region and climate to introduce a national method for desertification monitoring and assessment.
Keywords: Desertification assessment, Indicators, Index, Semi-arid region, Iran