Comparison of three methods based on the Temperature-NDVI diagram for soil moisture characterization

摘要

The triangle/trapezoid method is a well known method for retrieving spatialized soil moisture from remotely sensed temperature and vegetation index (NDVI). We selected three approaches with different requirements for ancillary data (triangle empirical method by Sandholt et al. [7], trapezoid method by Moran et al. [2], SVAT triangle method by Carlson et al. [3]-[6]). The empirical inversion is well suited when no information on meteorological data is available. Otherwise, one can build theoretical isolines in the T-NDVI-moisture space by applying the Penman-Monteith equation or by using a detailed SVAT model. The three approaches were compared by using remote sensing data obtained during the airborne HyEurope 2007 campaign over Camargue, south of France. We showed that the SVAT-triangle method has a potential for separately identifying surface moisture and root zone moisture.