فهرست مطالب

Journal of Radar and Optical Remote Sensing
Volume:4 Issue: 2, Spring 2021

  • تاریخ انتشار: 1401/03/30
  • تعداد عناوین: 6
|
  • Abolfazl Bameri *, Moazam Khaleghi Pages 7-15

    In order to be aware of groundwater-level fluctuations in arid and semi-arid regions, it is necessary to make an accurate forecast of the groundwater depth situation. The drying of Hamoon lake, severe water shortages and significant reduction in groundwater levels have led to critical environmental conditions in the Sistan plain. Spatial understanding of groundwater depth changes in the region and awareness of the severity of groundwater depletion are important for the development of water resources management strategies. Therefore, this study was conducted with the aim of zoning groundwater depth using geostatistics and GIS techniques in the agricultural lands of Sistan plain located in the east of Hamoon Lake, with an area of about 201000 ha. For this purpose, groundwater depth data were collected from 846 wells by field survey using piezometric wells in the study area. In this research, various geostatistical methods including deterministic interpolation method and geostatistical methods were evaluated to compare the prediction ability of groundwater depth spatial variations. The results showed that the intensity of groundwater depth changes in the study area with a coefficient of variation of 19.87% is moderate. The spherical model could better explain the spatial variation of the experimental variogram of the studied parameter in the region. Finally, the results related to the deterministic method of inverse distance weighted with power 2 estimates a better prediction for groundwater depth zoning than kriging and cokriging geostatistical methods.

    Keywords: Sistsn Plain, Geostatistics, Groundwater Depth, Hamoon Lake
  • Sara Shirzad, Babak Maghsoudi Damavandi, Hamed Piri * Pages 16-22

    In general, from ancient times to the present, there are various methods for collecting locationbased data, including astronomical observations, photogrammetry, mapping and remote sensing. Remote sensing is one of the data collection methods in which it has the least amount of direct contact with the objects and features being measured and unlike other methods in which human factors play a role in collecting and interpreting terrestrial data, in remote sensing method the task of collecting information will be the responsibility of the sensors. Due to the over-exploitation of natural resources, the landscape is constantly changing and monitoring these changes as well as updating maps is costly and time consuming, so many developed countries now have to prepare maps in Different levels use satellite data. The factors studied in this research include 1 preparation of land cover maps and land use of a part of Khuzestan lands. 2 Evaluation of bioecological potential in agricultural development of the study area by weighted overlap method. With regard to collecting information, studying the obtained maps and calculations, determining the criteria, final weights and classification of layers in determining the potential of the region for agricultural use, the amount of changes in agricultural areas between 2014 and 2016 was determined. According to calculations, it is about twelve percent, which according to the changes that have taken place are very significant and show the intensity of the changes in recent years. Loss of vegetation is a factor in increasing wind speed and destroying soil texture and structure. It is also a cause of dust, the result of which can be seen in recent years.

    Keywords: Weighted Overlap, Remote Sensing, Vegetation (Plant Cover)
  • Samad Fotoohi*, Hossain Negaresh, Roghayeh Delaram, Masoud Sistani Badooei Pages 23-32

    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.

    Keywords: Anthropogenic, Land Subsidence, Sentinel 1, Radar Interference, Normanshir-FahrajPlain
  • Hasan khaksar, Seyed Ahmad Almasi *, Ali Asghar Goharpor Pages 33-48

    This study presents an integrated method for identifying an important segment of traffic accidents in an intercity road network. The spatial analysis method is known as network Kernel Density Estimation (KDE). The importance of critical accident rate is that it takes into account several factors including exposure rates, type of road section, variance of accident data, etc. Also, in this study, we compared the results of the road severity index with the Kernel Density Estimation method. The results of the study were obtained for two almost identical models. We found that the key points determined by the Kernel Density Estimation method reflect the severely problematic component segments, and filter out components that are not vulnerable. This approach can help transportation officials and safety professionals prioritize locations that need more safety attention.

    Keywords: Crash, Kernel Density Estimation (KDE), Intercity Network, Severity Index
  • Study of urban green space and its changes using remote sensing techniques (Case study: Tabas city)
    Mahboubeh Shabani * Pages 49-59

    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.

    Keywords: Green space, Sentinel 2, Vegetation, NDVI, Tabas
  • Alireza Karimi * Pages 60-73

    Digital Elevation Model is a continuous statistical representation of the earth by a large number of selected points with known coordinates of length, width and height. The use of three-dimensional models of the earth's surface has a wide range of applications in many areas of research and implementation. It is high and the areas are level. All the resulting points have a height above sea level. Most GIS spatial analyzes use elevation data such as DEM. Using it, you can prepare a slope map and slope direction and perform various analyzes in three dimensions. Most of the time, DEM is also used as the bottom view of the maps. Elevation is used to extract height and height data. Major users (DEM) in the fields of civil engineering, surveying and photogrammetry, earth sciences, water resources management, military applications, telecommunications, urban planning digital land models as one of their information layers to achieve management, executive goals or produce new products using location-based. In this study, using images of ASAR ENVI SAT sensors in C band in the study area, we prepared a digital elevation model and then compared. And for verification, we compared this prepared model with the existing topographic maps at the scale of 1.25000 as well as the fixed points of GPS stations and also with the digital model obtained from (SRTM) in terms of elevation. The results of radar image processing in C bands of ENVI SAT ASAR sensor and its comparison with the data of the surveying organization indicate that the data processed from C band gives more favorable results and close to the ground control points, but considering Due to the correlation between GCP points and DEM obtained from topography, production conditions using satellite images are not favorable for the region. GCP captured the height points of radar images are in better and more favorable conditions according to Table (4) which shows the standard difference and this indicates the superiority of radar images for DEM production. Digital model comparison ratio with topographic points, shows the accuracy of satellite images in flat areas. In mountainous areas, due to the inclination of the points and creation of incoherence points, it is not continuous shadow and the level curve lines are intermittent.

    Keywords: Digital DEM Altitude Model, Interference Measurement, GCP & GPS Points, CBand, Sensor ASAR