Vegetation water content of crops and woodlands for improving soil moisture retrievals from coriolis windsat

Estimation of vegetation water content (VWC) by shortwave infrared remote sensing improves soil moisture retrievals. The largest unknown for predicting VWC is stem water content; for woodlands, stem water content is expected to be proportional to stem height. Airborne imagery were acquired and photogrammetric structure-from-motion point clouds were used to estimate heights for mixed conifer and deciduous hardwood woodlands in eastern Maryland. The calculated stand heights were only weakly correlated with measured data. The normalized difference infrared index (NDII) and normalized difference vegetation index (NDVI) from both Landsat 8 Operational Line Imager and WorldView 3 were used to estimate canopy water contents. There were no relationships between canopy water contents and spectral indices, which suggested an allometric approach may not be feasible for woodlands. However, VWC was linearly correlated with crop canopy water contents, and provides an approach for remote sensing of VWC.