National Decadal Wetlands Change Atlas

National Decadal Wetlands Change Atlas

Subject :Environment

• Published by the Space Application Center (SAC), the 2022 Atlas provides data on wetland number and extent in 2017-18 and an assessment of change in data since 2006-7 which was recorded in the National Wetlands Atlas 2011.
• In a marked improvement from the previous iteration, the 2022 Atlas also presents basin-wise and biogeographic zone-wise information on wetlands distribution and extent.
• The 2022 Atlas concludes that the number and extent of wetlands having areas equal to or greater than 2.25 hectares (ha) have increased during the 2006/7-2017/18 period. The Atlas maps 231,195 wetlands (having an area equal to or greater than 2.25 ha) spanning 15.98 million hectares (4.86 percent of the country’s geographical area). In the 2006/7, 212,385 wetlands (>=2.25 ha) spanning 15.34 million ha were reported. Thus, the assessment concludes that in a decade, the number of wetlands has increased by 18,810, and the area by 0.64 million ha.
• The assessment states that natural coastal wetlands are declining (from 3.69 million hectares to 3.62 million hectares in ten years). An increase in the area has been reported for mangroves (by 18,662 ha), creeks (26,929 ha), and coral reefs (2,784 ha); however, the inter-tidal mudflats have receded by 116,897 ha, and so have salt marshes (by 5,647 ha). Gujarat stands out as the state with the most extensive loss of mudflats.
• The natural inland wetlands have remained mainly stable, marginally increasing (from 42,157 to 42,779 in terms of numbers and from 6.93 million ha to 7.02 million ha in terms of the area during 2006/7-2017/18).
• On the contrary, the human-made wetlands recorded a consistent increase. The area under saltpans increased by 93,139 ha, and aquaculture ponds increased by 15,692 ha. West Bengal and Odisha have seen the most significant increase in area under coastal aquaculture.
• Similarly, all inland human-made wetlands increased during the two assessment cycles. Of the 0.52 million ha increase in the inland human-made wetlands, a majority was accounted for by reservoirs and barrages (0.31 million ha), tanks and ponds (0.15 million ha) and inland aquaculture ponds (0.06 million ha). Much of this increase has occurred in Maharashtra, Madhya Pradesh, Andhra Pradesh and Telangana.
• The report also mentions that during 2006/7-2017/18, 308 natural wetlands (7,470 ha) were lost, whereas 811 new wetlands (22,673 ha) were recorded. In the human-made wetlands category, 1,034 wetlands (17,819 ha) were lost, whereas 14,012 new wetlands (388,995 ha) were recorded.
• The Ramsar Convention on Wetlands defines wetlands as “areas of marsh, fen, peat land or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six meters.”
• However, the Indian government’s definition of wetland excludes river channels, paddy fields and other areas where commercial activity takes place.
• The Wetlands (Conservation and Management) Rules, 2017 notified by the Union Ministry of Environment, Forest and Climate Change define wetlands as “area of marsh, fen, peatland or water; whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six meters, but does not include river channels, paddy fields, human-made water bodies/ tanks specifically constructed for drinking water purposes and structures specifically constructed for aquaculture, salt production, recreation and irrigation purposes.”