Landsat-derived monthly NDVI and MNDWI over Coongie Lakes Ramsar convention wetland in Central Australia (January 1988 to September 2011)

Monthly Normalized Difference Vegetation Index (NDVI) and Modified Normalized Difference Wetness Index (MNDWI) derived from Landsat satellite (30m spatial resolution) over the Coongie Lakes wetland area from January 1988 to September 2011. Normalized Difference Vegetation Index (NDVI) was used as a proxy of canopy ‘‘greenness” in our analyses. NDVI has been shown to be closely associated with various vegetation biophysical parameters (e.g., canopy cover, leaf area index, fraction of absorbed photosynthetic radiation and biomass) across different ecosystems. We calculated 24 years (January 1988 to September 2011) of monthly NDVI using Landsat surface reflectance band 3 and band 4. The formulation of NDVI is, NDVI = (NIR - Red) / (NIR + Red); where NIR is the near-infrared surface reflectance (band 4760– 900 nm) and Red is the red surface reflectance (band 3, 630– 690 nm). Modified Normalized Difference Wetness Index (MNDWI), a relatively strong performing metric compared to various water detection indices across a range of environments, is calculated as: MNDWI = (Green - MIR) / (Green + MIR); where Green is the green surface reflectance (band 2, 520–600 nm) and MIR is the middle infrared surface reflectance (band 51,550–1750 nm). The following two decision rules were uniformly applied to all Landsat pixels for presence of standing water Floodwater if (MNDWI greater than 0:123) or (MNDWI greater than -0.5 and Band4 less than 2000 and Band7 less than 1000)