Assessing the Impact of Gridded Precipitation Datasets on Blue and Green
Water Flow Accounting with Two Hydrological Models in the Damodar River
Basin, India
Abstract
The hydrological behavior and freshwater availability in any typical
river basin are highly dependent upon precipitation making it the most
crucial input variable for hydrological modelling. Precipitation as an
input variable to hydrological models is available in gridded form with
various spatiotemporal resolution. The variations in the model inputs
could be subjected to uncertainties in the hydrological model
simulation, which further affect the estimation of blue water flow (BWF)
and green water flow (GWF) of a river basin. In this study, we
investigated the effects of three gridded precipitation datasets
[Watch forcing data ERA-Interim (WFDEI); Princeton datasets; Indian
Meteorological Department (IMD)] on streamflow pattern, BWF, and GWF
using a semi-distributed hydrological model [Soil and Water Assessment
Tool (SWAT)] and a lumped rainfall-runoff model [Hydrological
Simulation model (HYSIM)] in the Damodar river basin situated in
eastern India. Both the models are simulated at daily time steps with
the calibration of ten years (1994 – 2004) and validation of five years
(2005 – 2010) at catchment outlet (Durgapur barrage) using three
precipitation datasets. The performance of all the three precipitation
products is evaluated on the basis of streamflow simulation for both
HYSIM and SWAT model at the basin outlet using the performance
indicators viz., Nash-Sutcliffe efficiency (NSE), coefficient of
determination (R2) and percent bias (PBIAS). The seasonal and annual
variation in precipitation values of the WFDEI, Princeton, and IMD
dataset could attribute to the significant variations in the performance
indicators. Subsequently, the best performance in streamflow simulation
is achieved by HYSIM model compared to SWAT with IMD precipitation
input. Both models showed remarkable differences in BWF and GWF
estimation due to changes in precipitation inputs. The results also
indicate that BWF is more sensitive to precipitation than GWF as BWF is
directly generated from precipitation. All the above observations
suggest that the choice of appropriate precipitation datasets is
essential to examine the catchment hydrological behavior, and it further
helps policymakers to make critical water management decisions.