Jiangsu Coastal Relative Sea Level Change And Its Effect On Radiation Sandbank Impact

The low and flat coastal plain, the vulnerable muddy coast and the Radiate Sand Ridges without external sediment supply in Jiangsu Province are extraordinarily sensitive to coastal dynamical changes. Faced with the possible sea-level rise in the future, inevitably, the region will be exposed to serious impacts comparatively.Based on the studies in sea-level rise and response of coastal zone by domestic and foreign researchers, integrated with the essential characteristics of Jiangsu coast and the Radiate Sand Ridges, laid emphasis on the effects of sea-level rise on the Radiate Sand Ridges and the Tiaozini sands in it's center region, the following case were discussed in the paper.(1) The recent relative sea-level rise in the region of the Radiate Sand RidgesFound on the structural and sedimentary features of the Radiate Sand Ridges, the rate of regional land subsidence was calculated (structural, balanced and compressed subsidence were considered respectively). The latest assessment of global sea-level rise in the past century that was carried out by IPCC was cited. Then the relative sea-level rise over the past century in the region of the Radiate Sand Ridges was calculated by add up the two items. Meanwhile, the relatively sea-level rise in the past decades were assessed by studying the tidal gauge records over the past 33 years, from 6 stations along Mid-Jiangsu coast. The correlations between the tide level of coast tidal gauge stations and the tide level of offshore sand ridges, and between mean high water level and mean water level as well as mean sea-level were discussed when studying the tidal gauge records.(2) Assessment of relative sea-level rise rate in the future in the region of the Radiate Sand RidgesAccording to the assessment of global sea-level rise in the coming century by IPCC (2001) report, and the rate of subsidence in the region of Radiate Sand Ridges, the relative sea-level rise in the coming century was forecasted quantitatively.(3) Response of the Radiate Sand Ridges to the relative sea-level riseBased on the background of sea-level rise in the future and the features of sediment dynamics on the Radiate Sand Ridges, the rule and tendency of the development of the Radiate Sand Ridges were analyzed using the data collected in situ and the long-term satellite images of the region. And concluded that theRadiate Sand Ridges will be adjusted greatly in response to the relative sea-level rise and the enhancement of tidal dynamics.(4) Effects of sea-level rise to the development and utilization of Tiaozini SandsBased on the tendency of the development of the Radiate Sand Ridges as a whole and on the developing mechanism of the Tiaozini Sands, developing tendency of the Tiaozini Sands in the future was concluded, that the vertical accretion of. the tidal flat will keep pace with the relative rise of sea-level. However, with the rising of sea-level and the tidal flat, the exploitation and utilization of Tiaozini Sands will be inevitably impacted in a certain degree.(5) DiscussionAt last, some cases mentioned in the paper but have not been well resolved were discussed. Including the correlation between the relative sea-level rise and the tidal range widening, and the relationship between relative sea-level and atmospheric pressure, as well as the limit of Tiaozini Sands vertical accretion.