Investigation of geodiversity in Lar basin, northern Iran

Document Type : Original Research Article


Department of Physical Geography, Shahid Beheshti University, Tehran, Iran


The diversity of natural processes including geological diversity (bedrock), geomorphic diversity (landform), sediment characteristics, geo-ecosystem in the Lar basin of Iran indicates the existence of geodiversity. Lar basin is located in the folded Alborz section of northern Iran and is limited on the east by Damavand volcanic and high peaks with 5594 m height. This research is conducted based on 1: 25000 topographic maps, digital elevation model, visible bands Landsat image version 8 on 26 August 2017 and field studies. The research method includes elevation zoning for landform energy mapping and landform fragmentation based on spectral homogeneity criterion, supervised classification and visual identification of the landfill has been performed to map the land surface and to calculate geodiversity indicators, the study area is divided into 46 zones. The findings of the study showed the existence of high and low geodiversity in the mountainous area and lowlands such as the bottom of river valley. This indicates a direct relationship between height and energy of the landforms. Also, most of the landform fragmentation in Lar basin and geological formation is located in areas with andesite, shale and green tuff. In general, the elevations of the center of the basin are around of Damavand Mountains and the northwest of the Lar basin has high geodiversity zones. These areas correspond to the high mountains, the glacial erosion range, the water distribution lines, and the first-order basins and rocky and bare lands. There are also mountainous areas with medium and low altitude or hillside with more slope and numerous valleys in the high geodiversity range. These two areas comprise more than half of the Lar Basin. In general, the geodiversity of the Lar Basin is dependent on elevation changes, diversity of geological formations, lithology, and vegetation.


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