جستجوی مقالات مرتبط با کلیدواژه "تصویر ماهواره ای" در نشریات گروه "زمین شناسی"

Water causes erosion of different forms in nature and creates diverse landforms on the earth’s surface depending on the manner it appears in nature. Although water is itself a former factor, it flows under the morphological effect of earth’s surface (Ramasht, 2005). The difference of earth’s surface topography and its consequent of water movement on it, cause the formation of sub-basins. In order to recognition of morphology and morphometry of Damavand cone, the region drainage basins must be distinguished. Therefore, in this study 5 drainage basins were identified based on the main criteria including topographic contours with 10 m intervals, drainage system (main and subsidiary rivers, main and subsidiary streams), DEM map of the region, slope map, aspect map and satellite images. Area, perimeter, height classification for classifying the morphological landforms in different levels, hypsometric, drainage density, etc. were then calculated by using the ArcGIS software. The Damavand cone, with a height more than 5,000 m above the sea level, has a very hard-pass slopes. Our purpose in this paper is to identify the effect of drainage basins conditions on the erosion and formation of geomorphological landforms by using of SPOT and ASTER satellite images as well as data analysis o in GIS environment.

Takht-e-Solayman zone is highly rich from the viewpoint of diverse morphological units. This morphological diversity is mostly caused by climatic factors and lithological characteristics, erosion, weathering processes and tectonic movements. Geomorphologic characteristics of Takht-e-Solayman zone are influenced by internal and external morphodynamic factors. As a geomorphologic-environmental achievement, this research has been dealt with the investigation of external factors. The available morphologic indications in the study area are divided into 3 general groups including morphodynamic, morphotectonic and morphogentic units and then presented in the form of a geomorphologic map. For this purpose, several new information layers of the zone are prepared in GIS environment using basic maps and field investigations and finally the landforms evaluated using ASTER and ETM+ satellite images.

Coastal zone of Khuzestan Province, which has an area of 1359832 hectare, is covered by various coastal (i.e. estuary, lagoon, delta) and continental (i.e. river and alluvial fan) environments. In this research, TM (1988) and ETM+ (2000) satellite images were used for recognition and differentiation of coastal environments. This study is based on combination of visual and digital image analysis in a GIS environment. The best images were formed by combination of 432 bands of TM and 431 bands of ETM+ sattelites. Polygon maps showed that most part (>70%) of region is covered by delta, lagoon and tidal flat environments.