title: Ecosystem evaluation (1989-2012) of Ramsar wetland Deepor Beel using satellite-derived indices.
abstract: The unprecedented urban growth especially in developing countries has laid immense pressure on wetlands, finally threatening their existence altogether. A long-term monitoring of wetland ecosystems is the basis of planning conservation measures for a sustainable development. Deepor Beel, a Ramsar wetland and major storm water basin of the River Brahmaputra in the northeastern region of India, needs particular attention due to its constant degradation over the past decades. A rule-based classification algorithm was developed using Landsat (2011)-derived indices, namely Normalised Difference Water Index (NDWI), Modified Normalised Difference Water Index (MNDWI), Normalised Difference Pond Index (NDPI), Normalised Difference Vegetation Index (NDVI) and field data as ancillary information. Field data, ALOS AVNIR and Google Earth images were used for accuracy assessment. A fuzzy accuracy assessment of the classified data sets showed an overall accuracy of 82 % for MAX criteria and 90 % for RIGHT criteria. The rules were used to classify major wetland cover types during low water season (January) in 1989, 2001 and 2012. The statistical analysis of the classified wetland showed heavy manifestation in aquatic vegetation and other features indicating severe eutrophication over the past 23 years. This degradation was closely related to major contributing anthropogenic factors, such as a railway line construction, growing croplands, waste disposal and illegal human settlements in the wetland catchment. In addition, the landscape development index (LDI) indicated a rapid increase in the impact of the surrounding land use on the wetland from 1989 to 2012. The techniques and results from this study may prove useful for top-down landscape analyses of this and other freshwater wetlands.
authors.affiliation: Remote Sensing and GIS, School of Engineering and Technology, Asian Institute of Technology, P O Box 4, Klong Luang, Pathumthani, 12120, Thailand, chitrini@gmail.com.
authors.forename: Chitrini
authors.initials: C
authors.lastname: Mozumder
authors.forename: N K
authors.initials: NK
authors.lastname: Tripathi
authors.forename: Taravudh
authors.initials: T
authors.lastname: Tipdecho
mesh_terms: D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D007194:India; D063809:Satellite Imagery; D053833:Wetlands
references.citation: Geomorphology (Amst). 2011 Jun 15;129(3-4):183-189
references.pmid: 21760655
references.citation: Environ Monit Assess. 2007 Apr;127(1-3):363-81
references.pmid: 17058002
references.citation: Environ Monit Assess. 2005 Feb;101(1-3):289-309
references.pmid: 15736887
references.citation: Sensors (Basel). 2008 May 26;8(5):3542-3556
references.pmid: 27879892
references.citation: Environ Monit Assess. 2006 Sep;120(1-3):221-41
references.pmid: 16758292