Reyhaneh Masoudi; Gholamreza Zehtabian; Hassan Ahmadi; Shahram Khalighi sigarudi
Abstract
Desertification is a major problem in many countries. International efforts have been considered to combat and prevent this phenomenon. The most important cases of these measures are the United Nations Convention to Combat Desertification. In this study, IMDPA model and GIS were used to assess desertification ...
Read More
Desertification is a major problem in many countries. International efforts have been considered to combat and prevent this phenomenon. The most important cases of these measures are the United Nations Convention to Combat Desertification. In this study, IMDPA model and GIS were used to assess desertification phenomena in Kashan Plain. Some indices of Climate and water criteria were selected to consider for each condition of the region. Final desertification intensity was calculated based on geometric average of the selected criteria and their indices. The numerical value was classified in 5 classes including non-significant, low, medium, severe and very severe and desertification intensity map was drawn using GIS in the studied period. According to the results, among the studied indices, the groundwater level depletion, EC and Transu aridity index with 3/82, 3/04 and 3/01 numerical values are the most effective factors. The threshold of ground water level, EC and Transu aridity index were determined respectively: more than50 cm/year, 2250-5000((μmohs)⁄(cm)) and 0/05-0/2. Also, the case study has classified in medium class of desertification with DS=2/4. Regarding the determined thresholds were specified the sensitive areas, and the required equipment are proposed to install on these areas for observing the thresholds.
E. S. Shokoohi; Gh. R. Zehtabian; A. Tavili
Abstract
More than 80% of Iran’s area has arid and semi arid climate. Therefore, Iran is exposed to desertification process. Practical activities in controlling desertification must be based on current desertification situation and its severity. Based on this theory, evaluating desertification rate indices ...
Read More
More than 80% of Iran’s area has arid and semi arid climate. Therefore, Iran is exposed to desertification process. Practical activities in controlling desertification must be based on current desertification situation and its severity. Based on this theory, evaluating desertification rate indices in Khezrabad region was done based on IMDPA model. In this research two factors with 10 indices were investigated. Each of the investigated indices was analyzed and scored based on work units. Data layers of each index were made by Arc GIS software. By compiling data layers and calculating geometric mean of indices, desertification rate map of the region was then prepared. According to the selected indices, final desertification map shows the mean rate of desertification. Soil index by 2.21 scoring value was classified in median class while water index by 1.46 scoring value was classified in poor class. Soil depth had the biggest influence while SAR and Cl of water had the least influence on desertification. Based on the assessments, geometrical mean of desertification rate quantity value for the entire region was 1.76, thus the entire region was classified in median class.
