Showing 8 results for Landslide
, 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.
, , ,
Volume 16, Issue 41 (9-2016)
Abstract
The KabirKooh landslide was studied as one of the immediate catastrophic events which causes falling rocks from the KabirKooh hillside and the obstruction of the Seymarreh river course and also formed a lot of geomorphological shapes in this area. This landslide was located at 5 km of the Poldokhtar city at the south between the Ilam and Lorestan province. The main purpose of this research to provide and analyzie of Morphometric feature of the landslide inclusive, width of the rupture surface (
), length of the displaced mass (
), length of the rupturesurface(
), width of the displaced mass (
), the depth of the rupture surface (
), the depth of the displaced mass to it will be discussed (
),(/
),(/), (/) and volume. For this work by using by using Global mapper11 software, to be conform the topographic area maps in the scale of 1/50000 and the digital elevation model. Arc Gis 9.3 and Surfer 10 software was used for preparing and producing new data and information. Considering the analyse of this indexs is, : equal to 15/5 
,: 16/06, :15.5,: 300 M,: 300 M, /:0.50, /:51.67, /:26.03 and volume 3908200970 
.
Siamak Baharvand, Salman Soori,
Volume 17, Issue 44 (6-2017)
Abstract
Landslide mapping is one of the approaches (which can be) used to define the slope stable critical areas and the maps prepared based on this demarcating are used in desining sustainable development. The purpose of this study is to compare the landslide susceptibility mapping models based on Fuzzy logic, Information value and area Density applied in the Chamsangar watershed. According to the tectonic and Iran old basins divisions, this basin is a part of folded Zagros. To study the stability of slopes in the Chamsang field, in first step the sliding point and subsequent distribution maps of landslide were prepared using satellite images and field visits (recording the sliding points by GPS). in this study, Landslide-related factors such slope, aspect, altitude, lithology, rainfall, landuse and distance from the road and drainage used in the landslide susceptibility analyses. To assess and classify was there models outputs the Sum of Quality (QS) index used. Results show that area Density model with QS=1.85 is the more suitable than Information value model with QS=1.60 and Fuzzy logic with QS=0.554 based on the out put of the area Density model, the 36.31, 44.78, 16.62, 1.65, and 0.63 percent of the area is located in very low, low, medium, high and very high risk classes, respectively.
Mrs Malihe Mohammadnia, Dr Gholamabbas Fallah,
Volume 18, Issue 48 (4-2018)
Abstract
Landslide, due to its dangerous nature in mountainous areas, usually causes morphology to suddenly collapse and causes major damage to residential areas, roads, agricultural lands, and so on. In this study, using the AHP model and fuzzy logic operators, we evaluated and zoned the landslide sensitivity in the Pseudogene basin in Razavi Khorasan province. The eight main criteria of elevation, slope, tilt direction, distance from the waterway, distance from the road, distance from the fault, geology and land use associated with the occurrence of landslide phenomena were examined in total. The sub-criteria were weighted and fuzzy using the Frequency Ratio Model. The weight of the criteria was also determined using the AHP model. Then the landslide susceptibility map was prepared using fuzzy operators 9 / 0.8 / 0 and 0.7 and verified using the ROC curve. The results showed that the gradient factor had the most effect and land use factor had the least effect on the occurrence of slip in the basin. Validation results of the model showed a 90% accuracy of the landslide sensitivity map with a 0.7% operator in the basin. Therefore, the fuzzy gamma model with the 7th operator provides the best form of landslide susceptibility map in the Pseudogene basin.
Siyamack Sharafi, Masoud Sadeghirad, Zahra Javadi Nia,
Volume 20, Issue 56 (3-2020)
Abstract
the occurrence of landslides in the direction of rivers, especially in the mountainous regions of Zagros range are processes that block rivers and form lake barriers. Della Landslide is an example of such landslide that occurred in the course of Shimbar River drainage and eventually created Lake Shimbar. geoarchaeological field studies performed on this slide using topographic maps, geological, digital model of the area, satellite images and Arc GIS software on the landslide and basin lake Shimbar resulted in the identification of the causes of landslides and changes in three stages of the lake. This study eventually rebuilds Paleogeomorphology of landslide area and the lake's dam Shimbar. The results showed that the main cause of the occurrence of landslides were tectonic processes in the region and based on archaeological evidence and the archaeological excavation of the canal, the landslides occurred before 2000 years ago. The formation and changes in the scope and depth of the lake Shimbar in 3 stages blocked the migration routes in area for a long time.
Abolghasem Goorabi,
Volume 21, Issue 60 (3-2021)
Abstract
Radar sensors obtain regular and frequent radar images from which ground motion can be precisely detected using a variety of different techniques. The interferometric synthetic aperture radar (InSAR) is utilized to retrieve the spatial characteristics of the largest coseismic landslide Maleh-Kabood, induced by the Ms 7.3 Azgleh earthquake in Kermanshah Province, Iran. The available seven interferometric pairs with good coherence selected from the Sentinel 1, 2 imagery data covering the NW-Zagros mountainous area are used in the study. The post-seismic topographic change relative to the pre-seismic over the landslide area is spatially mapped from the persistent scatterer network adjustment solution. The quantitative estimation of local elevation change, mass sliding volume and deposit thickness associated with the landslide is conducted. The spatial pattern of mass movement suggests that the giant landslide is characterized by a major sliding length of 3570 m along the NW–SE directions with an extension width of 1500-2300 m along the Maleh-Kabood and Ghoch-Bashi gully respectively, and a peak height change of 20 m in the vertical direction neat mountain ridge. The affected area of landslide mass movement reaches 6.0 km2 (577 Hectares) with the volume up to 500 million m3. Comparative studies indicated that the Maleh-Kabood landslide is the largest landslide in Iran over the past few centuries. The study also demonstrates the potential of InSAR technique as an alternative to allow the quantitative measurement of mass wasting volume associated with earthquake-induced giant landslides.
Mehdi Feyzolahpour, Marziye Manafi, Reza Khoshraftar, ,
Volume 21, Issue 62 (10-2021)
Abstract
Reviewing the damage caused by landslide proves the need to examine the factors influencing the occurrence of this phenomenon and the prediction of its occurrence. Therefore, the purpose of this study was to improve the prediction of landslide occurrence in the Taleghan watershed using Shannon Entropy Theory. Among the factors influencing the occurrence of landslide, ten factors of elevation, slope, slope direction, geology, vegetation, land use, water congestion, fault, road, rainfall as independent variables and sliding zones were considered as dependent variables. Then, using the entropy index, weighing was calculated for each of these factors based on their effectiveness, and the value map of each parameter was calculated according to its weight. In the next step, by mapping these maps with the map of landslides, a risk zoning map for the basin was drawn up. After calculating the Shannon entropy index, it was determined that 86% of the landslide area is in three medium-risk, high-risk and highly hazardous areas, indicating that the final map of the zoning is based on the correct method. Also, the total quality index (Qs) in this method was equal to 2.3, which indicates that this method is more reliable and more suitable for zoning of landslide hazard in Taleghan watershed. The accuracy of the method (P) for the entropy model was equal to 0.24, indicating a more appropriate resolution of the risk zones in this method.
Aghail Madadi, Ebrahim Beheshti Javid, Nazfar Aghazadeh,
Volume 21, Issue 62 (10-2021)
Abstract
During the last years, following an increase in damages due to occurrence of landslides, human has decided to reduce such losses. Therefore, identifying regions susceptible to landslide and classifying them can partly help man to prevent from happening above phenomena. The current study aims to demonstrate factors contributing to occurrence of landslide in Candrigh Chay basin and then, flattening the basin regarding risks related to landslide event using one methods, Network Analysis Process. In this direction, as respects to basin morphology and also, findings of past researches , ten factors involved in occurring landslides in Candrigh Chay Basin were recognized and used : lithology , land use , rainfall , slope , slope aspect , road slide , sluice power index (SPI), sediment transfer index (STI).Network Analysis Process(ANP) Method was implemented to score and classify factors and scales. Was carried out in order to measure classes of each parameter. The final map showed that the basin has 4 classes considering landslide. Findings reveal flats with low risk and flats with high risk have the least area in Candrigh Chay basin. On the other hand, flats with medium risk and high risk allocate the most area of basin for themself. Comparing slid surfaces with flats facing risks indicates regions located at high and average risk class possess most areas of slide surfaces so that a flat involving very high risk and a flat with high risk devote 35 percent (79km²) and 32/6 (72km²) of landslides for themselves, respectively. In other words, more than 77 percent of landslides conform to flats covering very high and average risk. Moreover, petrology, slope, and, sluice slide were identified as the most effective agents in occurring land_slides. One models, Network Analysis Process (ANP) were utilized through this project
