Meghalaya - Ministry of Environment and Forests

4.0 DATA USEDRemote sensing dataIRS P6 LISS III data was used to map the wetlands. IRS P6 LISS III provide data in 4 spectral bands; green,red, Near Infra Red (NIR) and Short wave Infra Red (SWIR), with 23 m spatial resolution and 24 day repeatcycle. The spatial resolution is suitable for 1:50,000 scale mapping. The state of Meghalaya is covered in 6IRS LISS III scene (Figure 5). Two date data, one acquired during March and another during January wereused to capture the pre-monsoon and post-monsoon hydrological variability of the wetlands respectively(Table-2). Figure 6 shows part of Meghalaya as seen in the LISS III FCC of post- monsoon pre-monsoon datarespectively.Figure 5: IRS P6 LISS-III coverage (path-row) of MeghalayaTable-2: Satellite data usedSl.NoResourcesat LISS IIIPath/ RowPost-MonsoonPre-Monsoon1 109/53 Oct 27, 2006 Mar 20, 20072 109/54 Oct 27, 2006 Mar 20, 20073 110/53 Dec 14, 2007 Mar 25, 20074 110/54 Dec 19, 2006 Feb 10,20065 111/53 Nov 25, 2007 Jan 22, 20066 111/54 Nov 30, 2006 Mar 30, 2007Ground truth dataRemote sensing techniques require certain amount of field observation called “ground truth” in order toconvert into meaningful information. Such work involves visiting a number of test sites, usually taking thesatellite data. The location of the features is recorded using the GPS. The standard proforma as per theNWIA manual was used to record the field data. Field photographs are also taken to record the water quality(subjective), status of aquatic vegetation and water spread. All field verification work has been done duringOctober and November 2008.Other dataSurvey of India topographical maps (SOI) were used for reference purpose. Lineage data of National WetlandMaps at 1:50,000 scale was used for reference.9