Characterization of Low Flows for Water Resources Management in the East River (Dongjiang) Basin

Principal Investigator:
Chen, Yongqin

Co-investigator(s):
Fung Tung
Leung Yee
Xia Jun
Shao Quanxi
Chen Min-jian

Summary:
Water resources in the East River basin have been highly developed and heavily committed for a variety of uses such as water supply, hydropower, navigation, irrigation, and suppression of seawater invasion. In recent years, the East River provides supply to meet about 80% of Hong Kong's annual water demands. Low-flow conditions and hydrologic droughts are obviously very crucial to the reliability and vulnerability of the East River water resources systems to satisfy the multiple objectives of water uses. This study is therefore proposed to employ hydrologic analysis methods for low-flow characterization and modeling techniques for optimization of water resources systems under low-flow conditions.This research will advance the state-of-the-art of low-flow hydrology through studies for developing and applying a variety of techniques and models (both statistical and analytical) to characterize and estimate low-flow regimes. Two techniques, frequency analysis and baseflow recession analysis, will be performed to characterize low flows in terms of minimum average-streamflow rates and the associated probability distributions. To estimate low-flow statistics at ungauged sites, this study will adopt a regional hydrologic modeling approach to developing statistical relationships (both ordinary regression and geographically weighted regression) between low-flow statistics at gauged sites and a number of drainage basin characteristics derived from maps and remote sensing images. Finally, impacts of low flows on water quality and other water uses will be assessed and, multi-objective programming techniques will be applied to optimize water resources systems for the formulation of management strategies and plans. This study will not only have tremendous scientific merits, but also highly valuable practical significance and enormous relevance to Hong Kong.