| Title: | Combininig satellite radar altimetry, SAR surface soil moisture and GRACE total storage changes for hydrological model calibration in a large poorly gauged catchment |
| Authors: | Milzow, C., P.E. Krogh and P. Bauer-Gottwein |
| Year: | 2011 |
| Journal: | Hydrology and Earth System Sciences |
| Volume (Issue): | 15 |
| Pages: | 1729-1743 |
| Article ID: | |
| DOI: | 10.5194/hess-15-1729-2011 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | climate data effects |
| Secondary Application Category: | hydrologic assessment |
| Watershed Description: | 170,000 km^2 Okavango River in Angola, Namibia and Botswana in southern Africa (portion of the watershed that drains to the Okanvango wetland delta) |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | The availability of data is a major challenge for
hydrological modelling in large parts of the world. Remote
sensing data can be exploited to improve models of ungauged
or poorly gauged catchments. In this study we combine
three datasets for calibration of a rainfall-runoff model of
the poorly gauged Okavango catchment in Southern Africa:
(i) surface soil moisture (SSM) estimates derived from radar
measurements onboard the Envisat satellite; (ii) radar altimetry
measurements by Envisat providing river stages in the
tributaries of the Okavango catchment, down to a minimum
river width of about one hundred meters; and (iii) temporal
changes of the Earth’s gravity field recorded by the Gravity
Recovery and Climate Experiment (GRACE) caused by total
water storage changes in the catchment. The SSM data
are shown to be helpful in identifying periods with over-respectively
underestimation of the precipitation input. The
accuracy of the radar altimetry data is validated on gauged
subbasins of the catchment and altimetry data of an ungauged
subbasin is used for model calibration. The radar
altimetry data are important to condition model parameters
related to channel morphology such as Manning’s roughness.
GRACE data are used to validate the model and to condition
model parameters related to various storage compartments
in the hydrological model (e.g. soil, groundwater, bank storage
etc.). As precipitation input the FEWS-Net RFE, TRMM
3B42 and ECMWF ERA-Interim datasets are considered and
compared. |
| Language: | English |
| Keywords: | |