Wavelet analysis of the dynamic characteristics of saltwater intrusion – A case study in the Pearl River Estuary of China

摘要: Abstract The Modaomen Waterway (MW), a major outlet of the Pearl River Estuary, is crucial source water supply for Macao and Zhuhai City in Southern China. This waterway frequently affected by saltwater intrusion from South Sea, which has caused serious shortage recent years. For planning management at this it necessary to understand characteristics particularly low flow period year. However, as result multiple impacts tide, river discharge, wind, topography, channel bathometry, some other factors, into highly non-linear. In order account non-linear characteristics, wavelet method was used analyze tidal range, salinity impact range discharge on salinity. Results show that Sanzao station Pinggang both exhibit stable 14.8-day MW largely impacted during stream periods. flows upstream don't any characteristic, it, however, critical mitigating intrusion. A minimum total 2 500 m 3 /s Sanshui Makou stations been practiced threshold safe supply. study found percent time when below maximum permissible 250 ml/g increases up 50–70% pumping 250 mg/l greater than /s. Planning operation politically, economically mostly importantly technically challenging, findings can provide guidance further research. example, phase lag average quantified be 3.4–3.8 days. would suggest store freshwater backup storages needs least 4–5 days ahead spring tide so avoid Safer strategies developed scheduling reservoir operations maintain pumping.