فهرست مطالب مهرداد اکبری مهر

One of the most common natural phenomena occurring in mountainous regions of the world is landslide which causes critical damages and is considered as a natural disaster.  Iran is a country which annually suffers from this disaster and its consequent damage of about 500 billion Rials. Over the last 15 years, an increasing number of researches have aimed to demonstrate the applicability of the images captured by the space-borne Synthetic Aperture Radar (SAR) sensors in sensors. InSAR (SAR interferometry) is currently one of the most exploited techniques for the assessment of ground displacements, and is becoming a consolidated tool for Civil Protection institutions addressing landslide risk. Analyzing satellite SAR data plays a major role in investigating landslide related events at different stages, including detection, mapping, monitoring, characterization and prediction. In this regard, Masouleh region is highly important in terms of geology, geomorphology, and high potential for landslide occurrence. Therefore, in this study in order to create the displacement time series of the region, 11 radar images of the ALOS/PALSAR satellite within the time range of 2008 to 2010 were obtained and analyzed via Small Baseline (SBAS). The slide active zones were investigated based on geological field studies and the geomorphological characteristics of the region verified the displacement of various parts of the slide. The analysis results demonstrated that the highest displacement rate along the satellite view in the northern region, older and younger is 51, 46 and 70 mm/year, respectively, distancing from the satellite.  

Landslide is one of natural hazard which often occur in mountainous regions with high precipitation and seismic activity. Iran because of having vast mountainous areas is one of susceptible countries in occurrence of landslide. Case study area of this paper is an instable slope which a village named Gougerd is located on downstream of it. This village is located near Khoy city northwest of Iran in western Azerbayjan province. The purpose of this study is using two different methods in the Geomatics field in order to monitor the probable downward movement of the Gougerd village slope. Differential SAR interferometry (DInsAR) and Global Positioning System (GPS) observation is used as beneficial tools to evaluation and monitoring of surface displacement caused by landslide. 24 SAR images are provided spanning 2003-2010 for InSAR technique processes to study past mechanism of Gougerd slope. Displacement field map and time-series of selected PS pixels are the final products of InSAR analysis which show the range of the occurred mass movement along sensor line-of-sight. Also in order to more accurate evaluation and consideration a geodetic network with ~ 20 stations are constructed on the slope. Dual frequency GPS receivers are applied to do geodetic observations of this network to study present mechanism of the slope by determining the precise horizontal movement at some specific sparse locations. Static mode of GPS observations is done in 3 epochs during 2010-2011 with time interval of about 7 month. Using DInSAR technique beside GPS Geodetic observation method released useful qualitative and quantitative information about downward movement of Gougerd slope. Displacement analyses of both used methods represent significant movement especially on the upstream of Gougerd slope affected by landslide creeping. GPS and InSAR results showed suitable compatibility and prove that these two methods are complementary each other appropriately to illustrate surface slow movement like landslide creeping as we used it in this research.