| Title: | Development of an evapotranspiration data assimilation technique for streamflow estimates: A case study in semi-arid region |
| Authors: | Zhang, Y., L. Zhang, J. Hou, J. Gu and C. Huang |
| Year: | 2017 |
| Journal: | Sustainability |
| Volume (Issue): | 9(10) |
| Pages: | |
| Article ID: | 1658 |
| DOI: | 10.3390/su9101658 |
| URL (non-DOI journals): | |
| Model: | GSWAT & SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | evapotranspiration assessment |
| Secondary Application Category: | model and/or data comparison |
| Watershed Description: | 10,000 km^2 Upper Heihe River, located in northwest China. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | Streamflow estimates are substantially important as fresh water shortages increase in
arid and semi-arid regions where evapotranspiration (ET) is a significant contribution to the water
balance. In this regard, evapotranspiration data can be assimilated into a distributed hydrological
model (SWAT, Soil and Water Assessment Tool) for improving streamflow estimates. The SWAT
model has been widely used for streamflow estimations, but the applications combining SWAT and
ET products were rare. Thus, this study aims to develop a SWAT-based evapotranspiration data
assimilation system. In particular, SWAT is gridded at Hydrologic Response Unit (HRU) level to
incorporate gridded ET products acquired from the remote sensing-based ETMonitor model. In the
modeling case, Gridded SWAT (GSWAT) shows a good agreement of streamflow modeling with the
original SWAT. Such a scant margin between them is due to the modeling domain mismatch caused
by different HRU delineations. In the ET assimilation case, we carry out a synthetic data experiment
to illustrate the state augmentation Direct Insertion (DI) method and a real data experiment for the
upper Heihe River Basin. The results demonstrate the benefits of the ET assimilation for improving
hydrologic processes representations. In the future, more remotely sensed data can be assimilated
into the data assimilation system to provide more reliable hydrological predictions. |
| Language: | English |
| Keywords: | evapotranspiration; streamflow; data assimilation; SWAT; semi-arid |