Identification of catchment functional units by time series of thermal remote sensing images

摘要

The identification of catchment functional behavior with regards to water andenergy balance is an important step during the parameterization of landsurface models.An approach based on time series of thermal infrared (TIR) data from remotesensing is developed and investigated to identify land surface functioningas is represented in the temporal dynamics of land surface temperature(LST).For the mesoscale Attert catchment in midwestern Luxembourg, a time seriesof 28 TIR images from ASTER (Advanced Spaceborne Thermal Emission andReflection Radiometer) was extracted and analyzed, applying a novel processchain.First, the application of mathematical–statistical pattern analysistechniques demonstrated a strong degree of pattern persistency in the data.Dominant LST patterns over a period of 12 years were then extracted by aprincipal component analysis. Component values of the two most dominantcomponents could be related for each land surface pixel to landuse data and geology, respectively. The application of a data condensationtechnique ("binary words") extracting distinct differences in the LSTdynamics allowed the separation into landscape units that show similarbehavior under radiation-driven conditions.It is further outlined that both information component values from principal component analysis (PCA), aswell as the functional units from the binary words classification, willhighly improve the conceptualization and parameterization of land surfacemodels and the planning of observational networks within a catchment.