Impact of Fully Coupled Hydrology-Atmosphere Processes on Atmosphere Conditions: Investigating the Performance of the WRF-Hydro Model in the Three River Source Region on the Tibetan Plateau, China

Abstract

The newly developed WRF-Hydro model is a fully coupled atmospheric and hydrological processes model suitable for studying the intertwined atmospheric hydrological processes. This study utilizes the WRF-Hydro system on the Three-River source region. The Nash-Sutcliffe efficiency for the runoff simulation is 0.55 compared against the observed daily discharge amount of three stations. The coupled WRF-Hydro simulations are better than WRF in terms of six ground meteorological elements and turbulent heat flux, compared to the data from 14 meteorological stations located in the plateau residential area and two flux stations located around the lake. Although WRF-Hydro overestimates soil moisture, higher anomaly correlation coefficient scores (0.955 versus 0.941) were achieved. The time series of the basin average demonstrates that the hydrological module of WRF-hydro functions during the unfrozen period. The rainfall intensity and frequency simulated by WRF-Hydro are closer to global precipitation mission (GPM) data, attributed to higher convective available potential energy (CAPE) simulated by WRF-Hydro. The results emphasized the necessity of a fully coupled atmospheric-hydrological model when investigating land-atmosphere interactions on a complex topography and hydrology region.

A Review on the Development of Two-Way Coupled Atmospheric-Hydrological Models

“…Ryu et al [73] applied the WRF-Hydro for flash flood forecasting in the Namgang Dam basin of South Korea; the results show a potential for the WRF-Hydro with optimized parameters to predict heavy rain-induced flash floods. Li et al [74] utilized the WRF-Hydro to simulate the atmospheric and hydrological processes in the Three-River source region, showing an NSE of 0.55 in comparison to the observed daily discharge. Fersch et al [75] used the offline WRF-Hydro model to calibrate parameters (with NSEs between 0.56 and 0.64), and then used the WRF-Hydro to reproduce the regional water cycle with calibrated parameters.…”

Energy and Water Cycles in the Third Pole

“…The relation of the atmospheric vertical motion with the climate was discussed by Tian et al (2021) [9] via climate diagnosis and statistical analysis. Moreover, [10] evaluated the runoff simulation skills via WRF-Hydro, and achieved an improvement of 6.6% in root mean square error against in situ measurements. The enhanced WRF-Hydro simulated an increase in latent heat flux, but a decrease in sensible heat flux and soil surface temperature due to the moist soil.…”