Sample Material of Our IAS Mains GS Online Coaching Programme
Subject: General Studies (Paper 1 - Indian Heritage and Culture, History & Geography of the World & Society)
Topic: Salient Features of World Physical Geography
Salient Features of World Physical Geography
National Wetland Atlas of India: A Review and Some Inferences
The National Wetland Atlas 20111 (hereafter the Atlas) had the objective to map all types of wetlands and to become a national database by bringing out state-wise detailed publications. The Atlas, apart from producing the maps, estimated the area, vegetation and turbidity levels of wetlands. The Atlas project used satellite images from the Linear Imaging Self-scanning Sensors-m (liss-iii) with a resolution of 23 metres and thereby able to view water bodies up to a size of 529 square metres. The project was led by the Space Applications Centre (sac) of the Indian Space Research Organisation (isro), and 25 other specialist institutions undertook the project in their respective states.
Though the Atlas is an earnest effort to use the advancements in earth observation technologies such as the remote sensing and geographic information system (gis) tools, it is riddled with definitional problems, inconsistency of method and a poor understanding of Indian wetlands. The review highlights some of these issues affecting “man-made tanks and ponds”, which constitute the largest chunk of the Indian wetlands.
This detail has to be understood against the 1992-93 estimate of total Indian wetlands as 8.26 Mha (million hectares). Even accepting the fact that the Atlas in 2011 used a better and smaller scale compared to the previous ones, it is very difficult to believe the variations in the estimates. In the intervening three decades, many wetlands are said to have shrunk rather than having increased. Some amount of analysis of larger-sized tank wetlands, if done, would have given a better picture of what is happening, rather than showing an increase in the wetland area.
Extent of WetlandsThe Atlas reports that Total 2,01,503 wetlands have been mapped at 1:50,000 scale... In addition, 5,55,557 wetlands (< 2.25 ha) have also been identified. Total wetland area estimated is 15.26 Mha, which is around 4.63% of the geographic area of the country... Area under inland wetlands is 10.56 Mha and area under coastal wetlands is 4.14 Mha. |
Confusing Classifications
The Ramsar Convention3 defines wetlands as “areas 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 metres”.
Based on this, A Directory of Asian Wetlands (Woistencroft, Hussain and Varshney 1989) classified all of Indian wetlands into eight classes.