Danielle Mitchell
Identifying Salinization through Multispectral Band Analysis: Lake Urmia, Iran ©2014
Lake Urmia, located in the Iranian provinces of West and East Azerbaijan, has been gradually, yet dramatically shrinking since the late 20th century. Surface water fluctuation up until the late 1990’s never caused any reason for alarm. Since 1998, Lake Urmia has lost a devastating amount of water. Reasons for the lakes demise have been related to climate change and poor water resource management practices within the lakes watershed. If predictions of total drought become a reality, millions of people living within the Lake Urmia watershed will be faced with life altering environmental conditions. A remote sensing based analysis of multispectral imagery was used to identify changes in key features (lake water, saline features and agricultural land) and analyze the magnitude of salinization over space and time. Landsat 5 (1990, 1998, and 2006) and Landsat 8 (2013) images (acquired from USGS Earth Explorer) were analyzed at approximately 8 year intervals between 1990 and 2013. Spectral bands from the visible and near-infrared (VNIR) range were used to classify features; with the additional inputs of the thermal infrared (TIR) and Tasselled Cap Transformation (TCT) bands to highlight the reflectiveness of features. Change detection analysis of the results highlighted an alarming surface water decrease and expansion of saline features during the analysis period. From 1998 to 2013: water area decreased by 3146 km² from a maximum extent of 4995 km² to 1849 km², saline features increased by 898 km² to cover an area of 1022 km² from 124 km² and vegetation cover increased from 1159 km² to 1656 km².