جستجوی مقالات مرتبط با کلیدواژه « Sentinel-2 » در نشریات گروه « برق »

Taftan is a semi-active volcano located in southeast Iran with many craters. The main objective of this study is to investigate whether subsidence or uplift in Taftan Peak. 58 Sentinel 1-A images acquired from January 2015 to December 2020 in the ascending orbit mode, and 102 Sentinel 1-A Sentinel 1-B images acquired from October 2014 to June 2020 in the descending orbit mode were preprocessed for this purpose. The interferograms with the permanent scatterer interferometry (PSI) method were created using SARPROZ and StaMPS softwares, in which atmospheric corrections were made automatically, and then the surface displacement of Taftan volcano estimated.The Line of Sight (LOS) displacement corresponding to the uplift was 0.5 mm to 1 mm yr-1 for the ascending orbit and 1 mm yr-1for the descending orbit. Because no GPS station was close to Taftan volcano, the GPS measurements of one station located in the study area (Saravan station) was used to check the accuracy of PSI method. The GPS station of SARAVAN has situated inside the town ,and it is appropriate to use and analyze PSI technique in this station. As a result, the researchers found that the PSI method is in accordance with the GPS data.

Plant species used for urban green space in arid and semi-arid regions are not very diverse and many of them are drought sensitive and have high water requirements. This study was conducted to select new species as well as drought tolerant species for planting in green space and afforestation around cities in arid and semi-arid regions such as Tabas. To conduct this research, the required images of Sentinel 2 satellite in the period of 2017, 2018 and 2019 were prepared. Then, by performing the necessary processes, the amount of vegetation was calculated. And finally, maps and diagrams related to each year in the study area in Tabas city, which includes the area under municipal irrigation, Munshi Bashi Children's Park, Women's Park, Golshan and Anonymous Martyrs Garden, Anonymous Martyrs Boulevard and Social Security Boulevard, an area of Imamzadeh Musa Ibn Jafar Kazem and Razavi town were prepared and presented. The final results indicate that in 1996 there was an increase in vegetation, in 1997 with a decrease in vegetation and in 1998 there was a slight increase in vegetation. Also, the amount of water in 1996, 1997 and 1998 was estimated to be 11,250 cubic meters, 1433 cubic meters and 17,200 cubic meters, respectively. The results of the present study give us a worrying result that one of the reasons for these results could be due to improper use of water and improper vegetation in the target areas. In the end, suggestions were made to improve the current situation.

The role of humans in anthropogenic erosion and geomorphological changes of its natural environment is very important. Its most important role in recent decades is the use of surface and groundwater resources, which has been clearly shown as the destructive effects of excessive use of groundwater. Therefore, the need for water resources has caused the withdrawal of these very valuable resources from the underground aquifers of the country, whether allowed or not, and is facing the risk of land subsidence. The construction of the dam was another destructive effect that played an important role in blocking the aquifer nutrition. Normanshir-Fahraj plain is one of the plains in the country which has been directly affected by dam construction and uncontrolled abstraction of groundwater. After the dewatering of Nesa Dam, we were witnessed many environmental and water crises downstream of the alluvial fans of Fahraj and Normanshir. The need for drinking water, irrigation of date orchards and other uses has led to high groundwater abstraction. Also, the subsidence is calculated using radar data Sentinel 1 satellite for 6 months about 10 cm, which is high. Therefore, it is necessary to pay attention to landslide risk management as well as to avoid secondary hazards such as the destruction of walls and buildings, road lines and the transfer of energy and infrastructure by the relevant governorate.

In recent years, it has occurred in different regions of Iran, especially the plains, and in most regions has caused this phenomenon to become a major regional and country crisis. Kerman desert province is no exception to this rule and most of its plains and industrial areas have suffered from this phenomenon and have high subsidence rates. The present study investigated the occurrence of this phenomenon using radar interferometry technique and Sentinel 1 satellite images in the period of 2019 and 2020 in Bardsir plain of Kerman province. To investigate the rate of subsidence in the region, initial processing was performed in remote sensing software and GIS and two Goldstein and Adaptive filters were used to evaluate the obtained results. The results show that the Goldstein filter has subsidence values up to 10 cm in certain ranges and the uplift values up to about 6.5 cm and the Adaptive filter have given the subsidence values up to 9 cm in some ranges and the uplift values up to about 5.6 cm. The reason for the difference in values in the results of these two filters is that in the Goldstein filter, the amount of coherence increases by manipulating the phases, so the image is brighter, thus the situation in this filter improves. But this is not the case with the Adaptive filter, and the phases are not manipulated, and in some areas, the amount of blurriness is higher in different parts of the image.