Estimation of grassland biophysical variables for Lake Qinghai watershed: Moving towards remote sensing products

摘要

In this study, an alpine watershed was selected, and four kinds of biophysical parameters (Leaf Area Index, LAI; Canopy Water Content, CWC; Canopy Chlorophyll Content, CCC; Fractional Vegetation Cover, FVC) were retrieved and their products were generated at the regional scale from 2013 to 2014. PROSAIL radiative transfer model and modified mixed sub pixel model were used to estimate these biophysical parameters based on Landsat 8 OLI surface reflectance data. The results suggested that the estimated biophysical parameters yielded a promising accuracy compared with the ground measurements. The inter-partition statistic was also conducted by analyzing the grassland peak growing season (July and August), and confirmed that the pasture yield and water stress condition of grassland in Lake Qinghai watershed of 2014 is better than 2013.