Mehdi Feyzolahpour, Neda Kanani,
Volume 0, Issue 0 (3-1921)
Abstract
“Desertification is a form of land degradation in arid, semi-arid, and semi-humid regions caused by climate change and human activities. The purpose of this research is to investigate the desertification situation in the Sirjan Plain region in the period from 1990 to 2023. Desertification in this area threatens human settlements. The purpose of this research is to combine several indicators to evaluate the state of desertification, and for this purpose, several spectral indicators are combined with each other to select the best indicator. In this research, based on albedo, MSAVI and SFI indices, desertification monitoring index (DMI) was proposed and the spatial and temporal distribution of desertification in the west of Sirjan was estimated in 1990 and 2023. To classify the results obtained from the DMI index, Jenks classification methods and quantitative index were used. Based on the results of the Jenks index, it was observed that the areas with very low desertification in 1990 were about 59.7 square kilometers, which decreased to 127.5 square kilometers in 2023, and 47.68 percent of the area has desertification. It has been very little. Areas with high desertification have faced a significant change and have reached 118.6 square kilometers in 2023 from 465.7 square kilometers in 1990. The results showed that Jenks classification method has a higher ability than the quantitative index with an overall accuracy of 82% and a Kappa coefficient of 0.86 in 1990. Finally, it was observed that the albedo index had the highest positive correlation compared to the DMI index. So that the correlation between these two indicators in 1990 and 2023 was estimated at 0.71 and 0.82, respectively.
Mrs Malihe Mohamadnia, Dr Abolghasem Amirahmadi, Dr Mohamadali Zanganeasadi,
Volume 22, Issue 66 (9-2022)
Abstract
The purpose of this research is to use granulometric analyzes in desertification studies in Gonabad city, To achieve this goal, after the preparation of geomorphological maps of the region, 14 sediment samples were taken from the erosion-sensitive facies of the region. In the laboratory, a series of sieve with a diameter of 2000, 1000, 500, 250, and 64 micrometers, and a container Gatherings of sediment smaller than 64 μm were screened. The results showed that the highest frequency of particle diameter in sand samples was in the 250-225 micron class. And, given the average particle relationship with their transport intervals, it can be concluded that the distance between the particles was close to a point. Variants of different samples varied from 1.502 to 1.319. The most prevalent plots of ridge and the smallest slopes with low slope were the highest. In surveys in the skidding section, precipitates were mostly positive tilted, indicating the prevalence of fine particles in the region.
Sara Kaviani Ahangar, Rasool Mahdavi, Gholamreza Zehtabian, Hamid Gholami, Ashok K Chapagain,
Volume 24, Issue 72 (3-2024)
Abstract
Desertification is a serious environmental and socio-economic threat to the planet. The aim of this study is to use a scientific, reasonable and repeatable method to evaluate the process of vegetation and land use as two important factors in the process of desertification on different scales (local-regional and global). In this study, Sarvestan plain in Fars province was selected as the study area. For this purpose, Landsat images were used for TM (1993), ETM + (2001 and 2006) and OLI / TIRS (2016). Image monitoring was performed using image differentiation, NDVI index difference and land use maps. In 1993, 2001, and 1993, and 2016 difference maps, the decrease in the amount of water in the mouth of Lake Maharloo can be clearly seen as increasing changes in the infrared band. The results of the difference between the vegetation index and the increase in vegetation in the form of agricultural lands in 2016 compared to 2006 and 1993. According to the results of the monitoring classification, from 1993 to 2016, irrigated areas decreased from 7.11 hectares to 0.7575 hectares, on the other hand, the level of saline lands increased from 143.99 hectares to 223.83 hectares and the level of cultivated lands increased. (Agricultural and horticultural) has increased from 113.28 hectares to 14/2014 hectares, which due to the importance of saline lands and land use change indicators in the studies of the desertification assessment process, it can be concluded that the desertification process in the study area is growing.
