| Popis: |
In order to monitor the canopy water content of winter wheat, canopy spectrums of winter wheat with narrow-band were resampled to broad-band according to relative spectral response (RSR) function of TM5. And then, normalized different water index (NDWI) and simple water index (WI) were calculated with broad-band reflectance. Fuel moisture content (FMC) and equivalent water thickness for canopy (EWTc) were got using dry weight, fresh weight and leaf area (index). The results show that b7 of TM5 is better than b5 in inversing canopy water content of winter wheat. Meanwhile, NDWI is more suitable than WI. Suitable fitting equations are built with NDWI (b4, b7) for FMC and EWTc, whose R2 reaches to 0.576 9 and 0.695 6, respectively. Finally, the spatial mapping of canopy water content is done with fitting equations. The results demonstrate that canopy water content of winter wheat is high in west and low in east in the studied area, and it's high in booting stage and low in milk stage. |
