The Sea-Level Changes in Hong Kong From Tide-Gauge Records and Remote Sensing Observations Over the Last Seven Decades

The importance of studying the sea-level change (SLC) in Hong Kong (HK) is emphasized by factors related to high population density, intensive urban, and industrial development, particularly along coast that involves a considerable landreclamation. To address this issue, we investigate spatiotemporal characteristics SLC HK territories analyzing tide-gauge (TG) records collected from 1954 2019 satellite-altimetry (SA) data 1993 2019. application ocean-tide inverted barometer corrections TG substantially decreased uncertaintie achieving submillimeter accuracy. rates detected at six stations vary significantly even within relatively small coastline. According our estimates, annual between 0.32 ± 0.51 4.19 0.46 mm/yr 1997 These large differences are different patterns ocean currents freshwater discharge Pearl River Estuary. empirical orthogonal function analysis confirms expected increasing rising with two anomalous periods during 2002-2003 2015-2016 likely attributed El Niño-Southern Oscillation (ENSO). SLCs positively correlated ENSO index precedes several months (normally 5 months) interannual SLC. GPS trends reveals prevailing subsidence territories, which aggravates relative estimates. Between 2019, absolute sea level raised rate 3.17 1.56 (when using GPS+TG) 2.88 0.59 SA observations).