Combining satellite data and appropriate objective functions for improved spatial pattern performance of a distributed hydrologic model


Demirel M. C. , Mai J., Mendiguren G., Koch J., Samaniego L., Stisen S.

HYDROLOGY AND EARTH SYSTEM SCIENCES, cilt.22, ss.1299-1315, 2018 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 22
  • Basım Tarihi: 2018
  • Doi Numarası: 10.5194/hess-22-1299-2018
  • Dergi Adı: HYDROLOGY AND EARTH SYSTEM SCIENCES
  • Sayfa Sayıları: ss.1299-1315

Özet

Satellite-based earth observations offer great opportunities to improve spatial model predictions by means of spatial-pattern-oriented model evaluations. In this study, observed spatial patterns of actual evapotranspiration (AET) are utilised for spatial model calibration tailored to target the pattern performance of the model. The proposed calibration framework combines temporally aggregated observed spatial patterns with a new spatial performance metric and a flexible spatial parameterisation scheme. The mesoscale hydrologic model (mHM) is used to simulate streamflow and AET and has been selected due to its soil parameter distribution approach based on pedo-transfer functions and the build in multi-scale parameter regionalisation. In addition two new spatial parameter distribution options have been incorporated in the model in order to increase the flexibility of root fraction coefficient and potential evapotranspiration correction parameterisations, based on soil type and vegetation density. These parameterisations are utilised as they are most relevant for simulated AET patterns from the hydrologic model. Due to the fundamental challenges encountered when evaluating spatial pattern performance using standard metrics, we developed a simple but highly discriminative spatial metric, i.e. one comprised of three easily interpretable components measuring co-location, variation and distribution of the spatial data.