Detection of Land Surface Albedo Changes over Iran using Remote Sensing Data

Abstract

Albedo is one of the key parameters in climatic studies. Investigating its temporal and spatial behavior can be a tool for understanding environmental changes. The MODIS sensor continuously produces the land surface albedo on a global scale and with the appropriate spatial resolution and makes it available to researchers. In this study, to analyze Iran’s surface albedo trend, first, the daily albedo data of the MODIS on Iran in the period from 1/1/2001 to 12/30/2021 with a spatial resolution of 500 meters was prepared from the NASA website. After the necessary pre-processing, the long-term seasonal and annual trend of Iran's albedo was calculated at the 90% confidence level using the non-parametric Mann-Kendall test. The findings showed that the albedo trend is positive in the lowland interior areas of Iran and negative in the highland areas. Since the decreasing trend of albedo in highland areas indicates the reduction of snow cover in these areas, this issue can challenge the life and water resources of these areas that rely on the accumulation of snow.