Showing 6 results for Aster
Tahereh Karimi, Amir Karam, Parviz Zeaiean Firuzabadi, Seyyed Mohammad Tavakkoli Sabour,
Volume 0, Issue 0 (3-1921)
Abstract
Abstract
The catchment area of Alamut River in Qazvin province is witnessing numerous landslide hazards and landslides every year, which cause significant economic and sometimes life-threatening losses. Diagnosing the unstable areas of slopes through soil texture characteristics is a difficult task due to the difficulties of obtaining soil samples in mountainous areas. For this reason, in the present study, by using Sentinel A1 radar data, by determining the percentage of clay and sand in the soil, the soil texture map at the depths of 10, 60, 100 and 200 cm with two random forest (RF) and support vector machine (SVM) algorithms was produced in the eastern Alamut region, which was verified with soil profile samples. The results indicated that the Kappa index was more accurate in the RF model at three depths of 10, 60 and 100 cm. Then, by extracting the soil moisture map from Sentinel 2 data, at the same time as examining the internal friction angle of the types of soils in the region, comparing the slope and profile of the slopes and the shape of the convex (divergent) and concave (convergent) slopes, the unstable areas of slope movements, RF and SVM models were specified and validated with GPS data, field visits and Google Earth. Research findings show that the instability map resulting from the RF model has a higher accuracy (AUC=0.93) than the instability map resulting from the SVM model (AUC=0.90) and there is more instability in areas with medium to high slope and with soil texture of sandy clay loam and sandy loam. . This method has many advantages in preparing the soil texture map, determining the unstable areas of the slopes against mass movements and landslides, determining the vulnerable areas in mountainous areas and reducing financial and human losses.
, Vahid Riahi,
Volume 14, Issue 35 (3-2015)
Abstract
Iran's rural settlements, in spite of their comprehensive and multi-faceted developments in the last decades, are still considered to be among the settlements faced with crucial challenges in the face of environmental hazards. As a result, prearrangement for upcoming events and disasters, as well as paying attention to the management of rural disaster in dealing with particularly natural events turn out to be necessary. The rural areas of Sarwabad, in Kurdistan, are also considered among the areas susceptible to natural disasters, such as floods, earthquakes, and landslides. The purpose of the research is the identification of settlements, and safe and hazardous landslide zones with particular focus on disaster management in Sarwabad. This research is methodologically analytical and essentially functional, and, by using geographical information system (GIS) and the analytical hierarchical process (AHP), the researchers analyzed the data and the layers and provided the ultimate version of combined hazard maps and also overlaying maps for the purpose of factorial assessment. The findings have been in the form of spatio-populatory analysis of the settlements, and resulted in identifying the safe and unsafe villages and zones. Moreover, it is found that nearly 46 percent of the rural population and 31 villages of the area are located in safe or low-hazard-level landslides, while the rest of the settlements and rural population are located in the mid and high-hazard-level zones and, as such, are need to be secured in these zones.
Bakhtiar Feizizadeh, Ali Khedmat Zadeh, Mohammad Reza Nikjoo,,
Volume 18, Issue 48 (4-2018)
Abstract
Remote sensing technology is one of the most efficient and innovative technologies for agricultural land use/cover mapping. In this regard, the object-based Image Analysis (OBIA) is known as a new method of satellite image processing which integrates spatial and spectral information for satellite image process. This approach make use of spectral, environmental, physical and geometrical characteristics (e.g. texture, shape) together images contexts for modeling of land use/cover classes. The main objective of this study is to classify micro land use/cover of Meyandoab County by applying appropriate and effective algorithms and parameters in the object based approach. For this goal, Quick Bird and Aster satellite images were used within the integrated approach for processing and land use modeling. Accordingly, the land use map was classified in 9 class based on spectral and spatial characteristics. In order to perform OBIA, the segmentation was applied in the scale of 10, shape parameter of 0.7 as well as the compactness of 0.3. In terms of the classification task, fuzzy based algorithm and operators (AND, OR) was applied to detriment the membership functionality of segments for each class as well as classifying the related objects. We also applied textures, geometric, NDVI, GLCM, brightness algorithms based on fuzzy operators and assign class algorithm. In order to applying the validation of results, the accuracy assessment step was performed and the finally overall accuracy of 93.6 was obtained for the derived map. The Kappa coefficient was also detriment to be 0.92. The area under cultivation included respectively for lands of wheat and barley, prunes and plums, apples, vineyards and alfalfa hay2622.42, 4505, 4354.55, 4457.85, 14110.58 hectares.
Mr Mohammad Valaei, Dr Abdollah Abdollahi, Mr Aghil Khaleghi, Mis Eynaz Skandarzadeh,
Volume 21, Issue 60 (3-2021)
Abstract
Livestock farming is one of the most important activities in rural areasand most villagers, along with agriculture and horticulture, are engaged in animal husbandry (Livestock storage) and some products of the villagers in the agriculture and horticulture sector are devoted to livestock feeding, and others are consumed or sold, such as lob bits, live meat and etc. The purpose of this research is to analyze the effects of livestock economics on sustainable rural development. The present research is applied in terms of purpose and is descriptive-analytical in terms of its nature and method. Library and field studies have been used to collect data. The study area is East Gavdoul District in the Malekan County. According to the census of this region, there were 2306 households and 7468 inhabitants in 2016. According to the Cochran formula, 283 households were selected as the statistical sample of the research. This sample was randomly selected from households with livelihood economics. To analyze data on inferential statistics, one-sample t-test, regression, analysis and performance diagrams were used. The results of this study showed that there is a positive and meaningful relationship between livestock economy and sustainable rural development with a correlation of 0.400 and significance level of 0.30; So, for the dimensions of livestock economics, the economic sector with the impact of 0.743 and the social sector with the impact of 0.355 have the most impact on the sustainable rural development in the region. Also, the physical section with an impact value of 0.176 has had the lowest level of impact on sustainable rural development in the region. The general results of the research show that the economic sector with 0.41% and the social sector with 0.31% have a positive effect on the development and expansion of th
e livestock economy of the area.
Sayed Hedayat Sheikh Ghaderi, Abdulsalam aminpour, Parviz Ziaeian Firoozabadi,
Volume 24, Issue 72 (6-2024)
Abstract
Corona and Hexagon satellite photographs with a spatial resolution of 1.8 to 9 meters are a good source for monitoring and evaluating changes in surface phenomena. The purpose of this study is to monitor the changes in Zaribar Lake in the period 1969-2019 using the data of Corona, Hexagon and Aster satellites and their ability to monitor and extract the coastline, lake boundary and water surface. In this study, to geometric correction the corona and hexagon data from Google Earth images, linear extraction algorithms, binary mask and mean shift segmentation were used to extract the coastline and lake boundary, detect lake changes and extract and monitor the water area of Zaribar Lake. The results showed that in the first step: geometric correction of corona and hexagon images was obtained using Google Earth images with RMSE of 0.3 and 0.4 pixels. In the second stage, the linear extraction algorithm for extracting the lake boundary and coastline using corona and hexagon photographs has high accuracy and has a high correlation with the topographic map of 1.50000. In the third step, the unsupervised classification of binary mask method, in order to detect lake changes using corona and hexagon photographs, acceptablely identified the altered and unchanged pixels, so that 11 hectares of lake surface had the most changes. Finally, in the fourth step, it was found that the mean shift segmentation algorithm and threshold worked better by applying the corona, hexagon, and Aster events to extract the water surface, and in the meantime, the corona image performed better due to its higher resolution. The above results showed that Zaribar Lake decreased by 6.5% from 1969 to 2019 and the findings have a high correlation with the product of the ester aquifer. In general, the findings of this study show the potential of using digital image processing methods for corona and hexagon data to monitor and detect changes in lakes.
Mrs Zeinab Karimi, Sir Davood Mokhtari,
Volume 24, Issue 75 (2-2025)
Abstract
Rivers are environmental forms that react strongly to changes in their bed, tectonic is the most important factor affecting morphology of the river, causing significant changes in river systems. In this study, using the digital elevation model (DEM), Geographic Information System (GIS) and Global mapper 13, we investigated the effect of tectonic activity on river systems in the eastern slopes of Mullah Daghi, southeast of Zanjan province, this The area is drained by Abhar river. Using the Digital Elevation Model (DEM) in the Arc Gis 10.2 software environment, required maps including geological maps, topography and…, Geological map of 1: 250,000 leaves of Zanjan was used to prepare the fault map. In order to achieve the research objectives, tectonic activity indicators including: are Mountain front sinuosity, basin shape, drainage density, longitudinal gradient of the river, River maze, basin asymmetry, hypersometric integral, the topographic symmetry of the basin and the width of the valley floor to the height. The combination of these indicators is achieved by the tectonic activity index (IAT). The results obtained through the Iat index indicate the activation of tectonic and neotectonic in the watershed of Ardejin and Abhar and the moderate activities in the basin of the zareh bash basin. The impacts of these activities on river systems that are different from the tectonic indexes in the studied basins, such as river meanders(main stream), coniferous formation (Ardejin watershed basin), tilt watersheds abhar and Ardejin and the shape of the basins (Basin elongation zareh bash)
