| Title: | Stream flow simulation and verification in ungauged zones by coupling hydrological and hydrodynamic models: A case study of the Poyang Lake ungauged zone |
| Authors: | Zhang, L., J. Lu, X. Chen, D. Liang, X. Fu, S. Sauvage and J.-M. S. Perez |
| Year: | 2017 |
| Journal: | Hydrology and Earth System Sciences |
| Volume (Issue): | 21(11) |
| Pages: | 5842-5861 |
| Article ID: | |
| DOI: | 10.5194/hess-21-5847-2017 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | model and/or data interface |
| Secondary Application Category: | hydrologic assessment |
| Watershed Description: | 19,867 km^2 Poyang Lake ungauged zone drainage area, a tributary of the Yangtze River that is located in southeast China. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | To solve the problem of estimating and verifying
stream flow without direct observation data, we estimated
stream flow in ungauged zones by coupling a hydrological
model with a hydrodynamic model, using the Poyang
Lake basin as a test case. To simulate the stream flow of
the ungauged zone, we built a soil and water assessment
tool (SWAT) model for the entire catchment area covering
the upstream gauged area and ungauged zone, and then calibrated
the SWAT model using the data in the gauged area.
To verify the results, we built two hydrodynamic scenarios
(the original and adjusted scenarios) for Poyang Lake using
the Delft3D model. In the original scenario, the upstream
boundary condition is the observed stream flow from the upstream
gauged area, while, in the adjusted scenario, it is the
sum of the observed stream flow from the gauged area and
the simulated stream flow from the ungauged zone. The experimental
results showed that there is a stronger correlation
and lower bias (R2 D 0.81, PBIASD10.00 %) between the
observed and simulated stream flow in the adjusted scenario
compared to that (R2 D 0.77, PBIASD20.10 %) in the original
scenario, suggesting the simulated stream flow of the
ungauged zone is reasonable. Using this method, we estimated
the stream flow of the Poyang Lake ungauged zone
as 16.4 (+ or -6.2 billionm3 a-1), representing ~11.24% of the
annual total water yield of the entire watershed. Of the annual
water yield, 70% (11.48 billion m3 a-1) is concentrated
in the wet season, while 30% (4.92 billion m3 a-1) comes
from the dry season. The ungauged stream flow significantly
improves the water balance with the closing error decreased
by 13.48 billion m3 a-1 (10.10% of the total annual water
resource) from 30.20 (+ or -9.1 billionm3 a-1) (20.10% of the
total annual water resource) to 16.72 (+ or -8.53 billion m3 a-1)
(10.00% of the total annual water resource). The method can
be extended to other lake, river, or ocean basins where observation
data is unavailable. |
| Language: | English |
| Keywords: | |