Estimation of ELA of the geomorphic unit of Central Iran

Abstract

In this article tried to estimate the ELA in central Iran by Wright, cirque-floor altitude, Terminus-to-head altitude ratio, and Altitude ratio methods. Then to be introduced the best method to estimate the ELA. The linear relations in the Negar and Nesar slopes of the highest peak were calculated for investigation of the effect of the value of slope and height of the peak on the ELA. 3300 cirques were identified, according to the curve lines in topographic maps. The mountainous terrain in most parts is northwestern - southeastern and sometimes western-eastern. Investigation of cirques in different directions indicates that most glacier cirques are formed in the northeastern or southwestern slopes. The dispersion of the number of cirques indicates that Nesar slopes (Northeastern) of the geomorphic unit of Central Iran have better conditions for the formation of glacial cirques. 57.7% of the cirques were identified in the northeast slopes. Analysis of ELA was estimated by THAR applying the Wright method indicates, in terms of elevation and direction effects are more consistent with the environmental conditions. The ELA was estimated between 2743 meters and 3098 meters. The average of ELA unit was 2853 meters. Analysis of the results of the effect of the value of slope and height of the peak on the ELA indicates that 77% of the influence of the slope on the ELA difference in the Negar slopes and 35% of the influence of the height of the dominant circus in the Nesar slopes can be explained.

Keywords

• quaternary
• cirque
• ela
• terminus-to-head altitude ratio
• central iran