Estimating Biophysical and Biochemical Parameters and Yield of Winter Wheat Based on Landsat TM Images

摘要

This paper focuses on the methodology of estimating biophysical and biochemical parameters and yield of winter wheat based on LANDSAT TM images. In order to develop the method of retrieving wheat parameters from remote sensing data, five LANDSAT TM images were acquired respectively at erecting stage, jointing stage, heading stage, early grain-filling stage and grain-filling stage of winter wheat. Experiment sites' wheat biophysical and biochemical parameters such as biomass, LAI, chlorophyll, nitrogen content and yield were measured. Based on the TM images, vegetation indices such as NDVI, OSAVI, MSAVI EVI, SIPI and NDWI were calculated. Then the correlation coefficients between wheat parameters and spectral indices of the experiment sites were computed. According to the correlation coefficients, the optimal spectral indices for estimating wheat parameters were determined. The best-fitting method was employed to build the relationship models between wheat parameters and the optimal spectral indices. Finally, the models were used to estimate wheat biophysical and biochemical parameters and yield based on LANDSAT TM data. Research results show wheat parameter estimation models possessed more R² values than 0.615.