Improved simulation of soil water content by the combination of ground and remote sensing data.

The simulation of site water balance requires the assessment of actual evapotranspiration (ETA), which is highly variable both in space and in time depending on several factors (climate, soil, vegetation). In a recent work we proposed a new method based on remotely sensed NDVI data which can estimate daily ETA operationally over large areas. The current paper utilizes these ETA estimates to drive two crop coefficient models, WinEtro and FAO56, in the prediction of soil water content (SWC). The outputs of the simulations are evaluated versus daily measurements of SWC taken in a Tuscany forest site (Barbialla) during four years. The results obtained indicate the efficiency of the proposed data combination, which improves the SWC simulations of both models examined. Recommendations are finally expressed for the possible extension and enhancement of the method described.