عنوان مقاله [English]
Geomorphodiversity Investigation of Damavand volcano and its surroundings based on the GmI Index
Geomorphodiversity defined as “the critical and specific assessment of the geomorphological features of a territory, by comparing them in an extrinsic and in intrinsic way, taking into account the scale of investigation, the purpose of the research and the level of scientific quality”. Area with high geomorphodiversity can provide a wide range of services, including provisioning (food products), regulating (erosion regulation) and supporting (land and water as a platform for human activities). The geomorphodiversity of Damavand volcano and its surroundings require special attention to identification, management and conservation, prevent degradation and construction in vulnerable areas. Promoted recognition of Geomorphodiversity can provide useful information about the management of geomorphological heritage and how to better protect them against destructive human activities and environmental hazards. Also, the preparation of Geomorphodiversity maps, the identification of areas with high potential for regional development and geotourism, provide comprehensive information for designers, planners and responsible organizations in these areas and create solutions for the environmental complexities of the study area; therefore The main objective of the present study is identification and quantitative assessment of geomorphodiversity and the preparation of geomorphodiversity maps of the study area.
Damavand volcano was inscribed as Iran's first natural property in the national heritage list at the Cultural Heritage, Handicrafts and Tourism Organization on July 3, 2008. The data of this research include geology, drainage network, slope, roughness and landforms, which are related to the evolution of the physical landscape of the study area. Landsat satellite imagery, thematic maps, DEM10 meter, etc. are used to achieve the goals. In this study, geomorphodiversity quantitative index has been used for analyzing the results and the results has been validated by comparing with geomorphology map and field control. Geomorphodiversity index (GMI) is presented by Melelli et al. (2017). The value of geomorphodiversity is calculated from the sum of five factors including geological diversity, drainage network density diversity, roughness diversity, slope position index diversity, landform category diversity. All of them are grids of different terrain parameters.
Results and discussion
In the geomorphodiversity of the study area, the V1 class is 1.05%, V2, 25.84%, V3, 37.17%, V4, 22.14% and V5, 4.84% of the total area of the region. Distribution of geomorphodiversity of the study area is mainly related to the topography condition; the lowest value of the geomorphodiversity (V1) is related to the Damavand volcano cone, especially the lava plain in the northwest. The highest value of geomorphodiversity (V5) extends along the valley of Haraz, where different types of geomorphological processes are meeting, such as fluvial, glacial, hillslope, igneous, tectonic and etc. In other words, increasing the value of geomorphodiversity along the Haraz valley can be interpreted as a result of the frequency of the geomorphological processes presence. Validation results also showed that there is a good correlation between the geomorphodiversity index value, the number of different types of landforms and the average number of landforms. The most extensive area with the lowest value of geomorphodiversity is located in the northwest of Damavand and in the Sardagh plain. Along the Haraz valley, which has the highest geomorphodiversity, there are different types of landforms, including river terraces, lake terraces, landslide, talus, basaltic prisms, deep valleys, travertine landforms, high channel density and so on. In general, in the study area, the high value of geomorphodiversity is mainly located at the meeting place of Damavand volcanic lava with rivers.
The geomorphodiversity of Damavand volcano and its surroundings are one of the most important fortunes in the region. Geomorphological landforms have been maximized in these areas and offer a unique geomorphological complex. The geomorphological landforms density in these areas are maximized and provide a unique geomorphological collection. Areas with high geomorphodiversity are rich and unique collection of different types of landforms and geomorphological processes that require special attention for geotourism, scientific-educational, national and world heritage, geopark, and so on. In addition, the determination of areas with high geomorphodiversity is another way to promoting geomorphological heritage; In other words, geomorphodiversity are the backbone for identifying and assessing geomorphological heritage for various purposes of geotourism, national and world heritage, geopark, conservation of geomorphological heritage. To ensure that the values of these areas can be preserved for current and future generations, managing and conserving them is very important. Nevertheless, studies of geomorphodiversity are at an early stage and need more help and reflection by geomorphologists in collaboration with other researchers in the Earth sciences.
Keywords; Geomorphodiversity, Landform, Geomorphological heritage, Quantitative assessment, Damavand volcano