利用大万山附近1°×1°经纬度网格的卫星高度计资料(1993-2006),计算出珠江口绝对海平面的上升速率为0.30±0.05cm/a,与由卫星高度计得出的全球平均海平面的上升速率一致。珠江口各验潮站近40年的潮位变化趋势分析表明,珠江口海平面正加速上升,为全球气候变暖所致;珠江口海平面与全球温度变化和ENSO活动密切相关,一般在ENSO年海平面相对较低。以IPCC有关全球温度上升幅度的预报值和海平面与全球温度变化的关系为依据,预计到2030和2050年珠江口绝对海平面将分别上升6~14和9~21cm,若考虑地面沉降以及波动值,珠江口部分岸段相对海平面将可能分别上升30和50cm。
By extracting 1°×1° grid datum of satellite altimeters,we calculate the sea-level rising rate at Zhujiang (Pearl River)estuary as 0.30±0.05 cm/a over the period from 1993 to 2006,which is consistent with the global mean sea-level rising rate. Tidal records from six tide gauges in Zhujiang estuary show that the sea level is acceleratedly rising over last forty years (1960-2006),and it is the result of global climate warming. The sea-level fluctuations over this period are very closely correlated with ENSO activities,i, e. , showing low sea-level values in E1 Nino years and high in La Nina years. Considering the good correlation between sea level and temperature and the IPCC predications on the future global temperature,we suppose the absolute sea level in Zhujiang estuary will rise by 6-14 and 9-21 cm in 2030 and 2050,respectively. If taking the factors of ground subsidence and sea-level fluctuations into account, the relative sea-level in some parts of Guangdong coast may rise by up to 30 and 50 cm in 2030 and 2050, respectively.