Developing Vegetation Health Index from biophysical variables derived using MODIS satellite data in the Trans-Gangetic plains of India

Abstract

Basic requirement for crop growth monitoring is the efficient tool for retrieving different plant biophysical variables and its accuracy or reliability. In the present study, statistical approach is used to retrieve the three biophysical parameters i.e. leaf area index (LAI), Chlorophyll content (Cab), and leaf equivalent water thickness (Cw). Normalized Difference Vegetation Index (NDVI), Red Index (RI) and Normalized Difference Water Index (NDWI) were used to retrieve LAI, Cab and Cw respectively. Study area was Trans-Gangetic plain comprising of whole Punjab, Haryana, Chandigarh, Delhiand some parts of Rajasthan. Field measurements were done at 190 locations. Spectral measurements (wheat crop and soil) with ground held spectroradiometer (FieldSpec3), LAI using Canopy Analyzer (LICOR-2000) and leaf samples were collected for further analysis in laboratory. Satellite data used was MODIS Surface Reflectance Product (MOD 09). Vegetation Health Index (VHI) was developed using the retrieved LAI, Cab and Cw and study area was categorized into four groups based on VHI.