Integrating Field Experiments with Modeling to Evaluate the Freshwater Availability at Ungauged Sites: A Case Study of Pingtan Island (China)

Abstract

Predictions in ungauged basins (PUB) has been always a focus of hydrological research. The problem presented by ungauged basins is how to reasonably estimate water resource availability. To solve the issues of data scale, this study combines field experiments and hydrological models to estimate freshwater availability in a typical ungauged sea island located in southeastern China. The free parameters in the hydrological model were derived from the point-scale rainfall-runoff experiments rather than calibration using river discharge observations. The rainfall-runoff experiments were performed on six sites covering 11 land cover types. Model validation at a sub-catchment showed that the combined method could successfully reproduce monthly streamflow, with a Nash-Sutcliffe Efficiency of 0.82, correlation coefficient of 0.85, and flow volume error of 6.5%. The simulation results indicate high heterogeneity and distinct seasonal dynamics in freshwater availability across the entire island. This pioneering PUB study for Chinese islands could provide reference for planning and management of freshwater in a water shortage area.

Climate Variability and Climate Change Impacts on Land Surface, Hydrological Processes and Water Management

“…The MLR models are good for simulating and predicting pollutant load except for total nitrogen. Liu et al [20] integrated field experiments with modeling to evaluate the freshwater availability at ungauged sites in Pingtan Island, China. The simulation results indicate high heterogeneity and distinct seasonal dynamics in freshwater availability across the entire island.…”

The Impact of Reservoirs on Runoff Under Climate Change: A Case of Nierji Reservoir in China

“…[39]. The HIMS (Hydroinformatic Modeling System) model provides multiple choices describing each of the water cycling processes and accounts for the combined runoff generation mechanisms [40]. The advantage of HIMS model is its flexibility in providing alternative modules to accommodate hydrological simulation in different regions [41].…”

“…The advantage of HIMS model is its flexibility in providing alternative modules to accommodate hydrological simulation in different regions [41]. It is widely used in China, Australia, and other regions and shows good performances [40][41][42][43][44]. Therefore, this study applied the HIMS model to simulate runoff.…”