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

Basic requirement for crop growth monitoring is the efficient tool for retrieving different plant biophysicalvariables and its accuracy or reliability. In the present study, statistical approach is used to retrieve the threebiophysical parameters i.e. leaf area index (LAI), Chlorophyll content (Cab), and leaf equivalent waterthickness (Cw). Normalized Difference Vegetation Index (NDVI), Red Index (RI) and Normalized DifferenceWater Index (NDWI) were used to retrieve LAI, Cab and Cw respectively. Study area was Trans-Gangetic plaincomprising of whole Punjab, Haryana, Chandigarh, Delhi and some parts of Rajasthan. Field measurementswere 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 analysisin 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 groupsbased on VHI.