Rainfall validates MODIS-derived NDVI as an index of spatio-temporal variation in green biomass across non-montane semi-arid and arid Central Asia

Formica, Adam F, Burnside, Robert J and Dolman, Paul M (2017) Rainfall validates MODIS-derived NDVI as an index of spatio-temporal variation in green biomass across non-montane semi-arid and arid Central Asia. Journal of Arid Environments, 142. 11–21. ISSN 0140-1963

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    Abstract

    As satellite-derived normalized difference vegetation index (NDVI) is related to vegetation biomass, it may provide a proxy for habitat quality across extensive species ranges where ground-truth data are scarce. However, NDVI may have limited accuracy in sparsely-vegetated arid and semi-arid environments due to signal contamination by substrate reflectance. To validate NDVI as a vegetation proxy in the low-altitude deserts of Central Asia, we examine its response to precipitation across the migratory corridor of Asian Houbara. NDVI increases with precipitation, both spatially (adj. R2 = 0.58, p < 0.001) and temporally (mean adj. R2 across n=244, 1 degree cells = 0.44; GLMM across cells p < 0.001). More vegetated regions show a stronger temporal response of vegetation biomass for a given precipitation increment (slope of NDVI to precipitation in per cell temporal models increases with inter-annual mean NDVI; adj. R2 = 0.38, p < 0.001), reinforcing the conclusion that NDVI provides a proxy for vegetation abundance. The strong signature of rainfall shows MODIS NDVI offers a potentially powerful proxy for spatial and temporal variation in arid and semi-arid vegetation at a resolution of 1 degree and 1 year over the houbara's breeding and wintering range, and probably also at finer spatial resolutions.

    Item Type: Article
    Uncontrolled Keywords: ndvi,validation,precipitation,asian houbara,extensive grazing,pastoralism,global and planetary change,nature and landscape conservation ,/dk/atira/pure/subjectarea/asjc/2300/2306
    Faculty \ School: Faculty of Science > School of Environmental Sciences
    Depositing User: Pure Connector
    Date Deposited: 08 Mar 2017 01:41
    Last Modified: 09 Apr 2019 11:57
    URI: https://ueaeprints.uea.ac.uk/id/eprint/62881
    DOI: 10.1016/j.jaridenv.2017.02.005

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