Lake Urmia, which is a salt lake of Iran turns red color in dry season. As shown in Fig. 1, the lake color was blue in TANSO-CAI observation image on April 24, 2016. However, it reddened gradually and the red area spread widely on July 23, 2016.
The color change is caused by microalgae. Under the condition of high salinity and strong sunshine in dry season, the microalgae turn red due to a carotenoid production.
Meanwhile, the lake water is reduced by a dam construction, an irrigation agriculture and a rainfall decrease due to global warming. Fig. 2 shows the TANSO-CAI observation images of July from 2009 to 2016. As shown in Fig. 2, the large part of lake was exposed in 2014 and 2015. The lake area was reduced by 70 % at that time.
However, in 2016, the lake area looks like it is restored to the same as 2012. Various approaches such as patrolling illegal draining water and releasing dam water have been promoted. The effect might be appeared in the lake recovery.
※The TANSO-CAI image was composed of band2 (674nm) in red, band3 (870nm) in green and band1 (380nm) in blue.
Fig. 1. Lake Urmia in July from April 2016.
Fig. 2. Lake Urmia in 2009-2016.
