Space based observation on changing colours of Lonar Lake

The world's third-largest crater, Lonar Lake in Maharashtra’s Buldhana district went through a striking transformation recently. The colour of the lake which is usually emerald green, has turned to a pinkish hue. It is being said that this change has been brought about by the increase in salinity of the water, resulting in the growth of certain micro-organisms which produce a red pigment (carotenoid) thus changing the colour of the lake. For instance, most species of Halobacteriaceae produce a red-pink pigment due to the presence of bacterioruberin carotenoids. Similarly, Algae known as Dunaliella salina are green under favourable conditions. However, in saltier environments, a carotenoid pigment called β-carotene which is pink in colour, becomes more and more concentrated, in a measure to protect the cell from high salinity. This study analyses wide-swath, high-resolution Sentinel-2 multispectral images to observe the changes in turbidity of the lake in recent months. Sentinel 2 images have been atmospherically corrected and a semi-empirical algorithm has been used over the red band (665 nm) to compute the turbidity values. A change in the turbidity values with respect to time has been charted. Lake Lonar (Maharashtra): Turbidity variation Lake Lonar (Maharashtra): 26th April 2020

Satellite Image Turbidity Image Lake Lonar (Maharashtra): 1st May 2020

Satellite Image Turbidity Image Lake Lonar (Maharashtra): 6th May 2020

Satellite Image Turbidity Image Lake Lonar (Maharashtra): 11th May 2020

Satellite Image Turbidity Image Lake Lonar (Maharashtra): 16th May 2020

Satellite Image Turbidity Image Lake Lonar (Maharashtra): 26th May 2020

Satellite Image Turbidity Image Lake Lonar (Maharashtra): 31st May 2020

Satellite Image Turbidity Image Lake Lonar (Maharashtra): 5th June 2020

Satellite Image Turbidity Image Lake Lonar (Maharashtra): 10th June 2020

Satellite Image Turbidity Image