Using Remote Sensing Data-based Hydrological Model Calibrations for
Predicting Runoff in Ungauged or Poorly Gauged Catchments
Abstract
Because remote sensing (RS) data are spatially and temporally explicit
and available across the globe, they have the potential to be used for
predicting runoff in ungauged catchments and poorly gauged regions, a
challenging area of research in hydrology. There is potential to use
remotely sensed data for calibrating hydrological models in regions with
limited streamflow gauges. This study conducts a comprehensive
investigation on how to incorporate gridded remotely sensed
evapotranspiration (AET) and water storage data for constraining
hydrological model calibration in order to predict daily and monthly
runoff in 30 catchments in the Yalong River basin in China. To this end,
seven RS data calibration schemes are explored, and compared to direct
calibration against observed runoff and traditional regionalization
using spatial proximity to predict runoff in ungauged catchments. The
results show that using bias-corrected remotely sensed AET
(bias-corrected PML-AET data) for constraining model calibration
performs much better than using the raw remotely sensed AET data
(non-bias-corrected AET obtained from PML model estimate). Using the
bias-corrected PML-AET data in a gridded way is much better than using
lumped data, and outperforms the traditional regionalization approach
especially in headwater and large catchments. Combining the
bias-corrected PML-AET and GRACE water storage data performs similarly
to using the bias-corrected PML-AET data only. This study demonstrates
that there is great potential in using bias-corrected RS-AET data to
calibrating hydrological models (without the need for gauged streamflow
data) to estimate daily and monthly runoff time series in ungauged
catchments and sparsely gauged regions.