Estimation of Freezing Level Height, Equilirium Line and Permafrost Edge Altitude and Snow-Cover Percentage at Sabalan Mountain and Their Impact on Water Resources

Freezing Level Height (FLH), Permafrost Edge Altitude (PEA), Equilibrium Line Altitude (ELA) and Snow-Cover Percentage (SC) are considered as important components of assessing and investigating the status of water resources. Environmental Lapse-Rate (ELR) was used to calculate these parameters. Regarding to the problem of using Land-Based climatological stations data, gridded radiosonde data were used as a replacement. This database has a higher and proper spatial and temporal resolution. In the first stage, raw data were processed in the Python programming environment, and then the ELR ratios on the lower part of troposphere were estimated up to 6000m in order to be used in FLH calculation during 2008 to 2016 time period, FLH and ELR were together used to calculate PEA at Sabalan mountainous area. The results are presented in the form of diagrams, maps and tables. Snow-Cover status at the Sabalan heights was obtained from Terra and Aqua Modis images, during the same period and they were analyzed and presented on the basis of monthly, seasonaly and annually time interval. The SC levels and the FLH altitudes were analyzed and compared. The FLH position, and hypsometrical distribution interactions, can be used for investigation of water resources future, and the establishment of appropriate water management scenarios. The comparison of SC percentage and the FLH level pointed out more differences during warm-months and the less during cold and wet months of the year. Winterly FLH level of Sabalan mountain lies at the elevation classes of 1200-1700, 1700-2200 and 2200-2700m which shows a normal, semi-critical and critical state of water resources respectively that could affect water resources management policies.