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

• Main Authors: Xiaocong Liu, Zhonggen Wang, Yin Tang, Zehua Wu, Yuhan Guo, Yashan Cheng
• Format: Article
• Language: English
• Published: MDPI AG 2018-06-01
• Series: Water
• Subjects: PUB; rainfall-runoff experiments; distributed hydrological model; Hydro-Informatic Modelling System (HIMS); freshwater availability
• Online Access: http://www.mdpi.com/2073-4441/10/6/740

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.