Abstract:

The Pearl River Delta Region is one of the few regions in our country which are seriously threatened by storm surges. Affected by global warming and sea-level rise, the return period for storm surge in this area is obviously changing. According to Gumbel and Pearson Ⅲ, the return periods of 11 tide stations for storm surge in the Pearl River Delta Region are calculated separately and the results are compared. Gumbel and Pearson Ⅲ distribution curves of extreme storm surge are mapped. The results show that the Gumbel distribution curves in most tide stations agree better with the experience frequency dots than Pearson Ⅲ distribution curves, but the Pearson Ⅲ distribution curves in the other tide stations agree better with the experience frequency dots than the Gumbel distribution curves. It is the best way to integrate Gumbel and Pearson Ⅲ methods. We analyze the basic characteristics of the return periods for storm surge in this area. Finally, we summarize the relationship between storm surges and the typhoon path, astronomical tide and the terrain. All the calculated results would be useful for the planning and design department to make decisions. This research would provide a scientific basis for the government for storm surge prediction, coastal engineering design and estimation of disaster demage.

Key words: Gumbel distribution, Pearson Ⅲ distribution, return period, storm surge, the Pearl River Delta region