Mohsen Asadollahi; Mohammad Jafari; vahid sayare; Ali esmaeili; Mohammad Tahmoures
Abstract
Wind erosion is one of the most important aspects of land degradation in arid and semi-arid regions, which 20% of land area of the world has been influenced by wind erosion. The wind increases the desertification process by displacing sand dunes. Therefore, the stabilizition and preventing the moving ...
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Wind erosion is one of the most important aspects of land degradation in arid and semi-arid regions, which 20% of land area of the world has been influenced by wind erosion. The wind increases the desertification process by displacing sand dunes. Therefore, the stabilizition and preventing the moving sands is essential. A strategy to combat this phenomenon is to reduce wind speed or to increase surface cover and soil resistance against erosion winds. The application of mulch or soil cover is one of the methods widely used to stabilize moving sands. For this purpose, a study was done at the Research Station International Desert Research Centre in Kashan city. The main purpose of this study was to investigate the effect of Multivariate biopolymer treatment at three concentrations (15%, 30% and 60%) on the moisture content of three sand depths (first depth of 0-5 cm, second depth of 5-10 cm and depth of third 10-20 cm), and study this mulch Compared with levels without mulch on the sand. Results showed soil moisture retention in Mulching compared to the control treatment, and statistically, there was significant differences between different depths of soil moisture Mulching compared to the control treatment and in between the first, second and third depths, the first depth had the highest increase in moisture holding compared to the Control treatment.
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 ...
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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.
T Mesbahzadeh; H Ahmadi; Gh Zehtabian; F Sarmadian
Volume 63, Issue 3 , December 2010, , Pages 399-415
Abstract
Investigation and preparing of wind erosion intensity maps are the main objectives of this research. In this research, the working unit map was prepared and then nine effective factors in wind erosion according to IRIFR.E.A model are determined at each of seven homogeneous units. According to the results, ...
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Investigation and preparing of wind erosion intensity maps are the main objectives of this research. In this research, the working unit map was prepared and then nine effective factors in wind erosion according to IRIFR.E.A model are determined at each of seven homogeneous units. According to the results, active sand dunes and landuse change showed the highest value with the rate of annual sedimentation more than 6000 ton/km2 while lands surrounding the villages showed the least value with an annual rate of sedimentation of 150-500 ton/km2. Also considering whole area which is about 16161 hectares, around 1978 hectares are classified in low class of desertification; 7430 hectares in medium class while 6753 hectares in high and very high classes.