Estimating Net Primary Production for Croplands Using Advanced Wide Field Sensor (AWiFS) Time Series Data

Estimates of carbon flux are currently conducted using field measurements, atmospheric measurements, inventory data, and both biophysical and atmospheric modeling. In nearly all cases, with the exception of atmospheric modeling, field-scale measurements and modeling need to be scaled up using estimates of land cover and land management. Estimates of cropland fluxes using moderate resolution data (>500 m) have been difficult because of the poor spatial delineation of crop species and the representation of multiple crops with single satellite reflectance values. The Advanaced Wide Field Sensor (AWiFS) on board IRS-P6 provides relatively high spatial (56 m) and temporal resolution (5 day revisit) data which can be useful for estimating cropland fluxes. We will present current methods of estimating net primary production for delineated cropland fields using the AWiFS data. Results based on NDVI and two-band EVI will be compared and discussed. Impacts on terrestrial carbon flux modeling will be quantified and discussed.