Geomorphometry of the Glacial Cirques in Zardkuh Mountain, Iran

Abstract

Abstract Cirques as one of the glacial erosional forms are suitable indicators to recognize the environmental conditions of the Quaternary period. Therefore, considering the importance of glacial cirque landforms, identifying and mapping the distribution of the circus with their shape features meets the need of environmental science, especially geomorphology. In this paper, in order to identify the quantitative features of cirques in Zardkuh region, the second derivatives, including second-degree curvature of the plan, profile and general curvature along with slope as a primarily derivative were used from geomorphometry indices. To this end, 20 meter resolution digital elevation model was generated from 1: 25,000 topographic map which was used in the geomorphometric analysis. The result shows that secondary derivatives had higher performance in identifying the feature shapes of glacial cirques. Likewise, the plan curvature Index could truly present the headwall around the circus as well as profile curvature clearly showed the avalanche path. In conclusion, it seems that the second derivative indicators, including curvature’s family, have high capability to extract and detect different natural shapes from digital elevation data.