Multiscale Temporal Response of Salt Intrusion to Transient River and Ocean Forcing

Salt intrusion in surface waters endangers freshwater availability, influences water quality, and affects estuarine ecosystem services with high economic social values. transport the resulting salinity distributions result from non-linear interactions between salt dynamics. Estuaries are often considered under (quasi)-steady assumption or by focusing on specific timescales. Our understanding of their temporal multiscale response to transient forcing is limited, which hinders implementation effective mitigation strategies. We apply wavelet analyses quantify variability hourly seasonal timescales unravel its across scales. focus an estuary that undergoes significant forcing, Modaomen Pearl River Delta, year-long data generated a coastal ocean numerical model. results show this responds changes tidal riverine throughout year over interwoven highlight time both within given regime for transition regimes. They also suggest tides control more strongly than river discharge, even though discharge determines magnitude intrusion, thus modulates evolution time. propose broadly applicable framework calculate times simple data. These can provide first-order guidance design management strategies measures ensure access facilitate sustainable development.