NASA Releases Satellite Image Of Kashmir's Shrinking Wular And Dal Lakes; What Led To Their Decline?

National Aeronautics and Space Administrations (NASA) on Tuesday shared images of two major freshwater lakes in Kashmir Valley that show a significant decline. This picture of Kashmir’s Wular and Dal lake was captured by the Operational Land Imager (OLI) on Landsat 8 satellite on June 23, 2020. Wanmei Liang took the photograph for NASA Earth Observatory using Landsat data from the US Geological Survey. Emily Cassidy wrote a report that explains the causes behind the shrinking lakes of Kashmir.

The image shows two water bodies. The larger water body is Wular Lake, which is on the left side of the image. It is the biggest freshwater lake in India and one of the biggest in Asia. The lake is part of the Jhelum River and provides freshwater and fish to the people living nearby. The lake has several wetlands around it that are home to migratory birds, such as ducks, shorebirds, geese, and cranes. The lake is a “wetland of international importance” according to Ramsar International, which gave it this designation in 1990.

The smaller one is Dal, which lies in the middle of Srinagar, the valley’s largest city. The lake draws tourists with its house boats, markets, and marshes that float on the water. Around the lake, there are terraced gardens with fountains and various plants. 

Reasons Behind Wular Lake’s Shrinking

Eutrophication

The report says that influx of sediment and nutrients into the lake of over the past few decades has contributed to rapid growth in Algae and aquatic vegetation. The report cites Eutrophication, a process where organic and mineral nutrients supporting an abundant aquatic plant life, which in the process of decaying depletes the oxygen supply.

Urbanisation

According to the report, the conversion of forests into urban areas is a major cause behind the change in water quality. Discharge of heavy sediment, nutrient loads and untreated sewage into the lake has equally contributed in the shrinking. “Researchers in India used water samples and data from Landsat satellites to assess the biological health of the lake. They found that about 57 percent of Wular Lake was eutrophic in 2018,” the report mentions.

The report states that some of bright green area on the eastern side of Wular lake which used to be open water has now turned into nutrient-rich sediment and aquatic vegetation have filled in parts of the lake and contributed to its shrinking in recent decades.

Reason Behind Dal Lake’s Area Decline

The smaller Dal Lake has suffered a similar fate in response to land cover change. Researchers in Srinagar found that land conversion to urban development in the basin had worsened the lake’s water quality and contributed to its reduced size.

Percent Of Area Already Shrunk

A 2022 research using data from the Indian Space Research Organization’s (ISRO) LISS-IV instrument—found that Wular Lake’s open water area had shrunk in size by about one-quarter between 2008 and 2019. They found that between 1980 and 2018, Srinagar’s famous Dal lake shrunk in area by 25 percent