Waves
波浪

The wave data recorded by ship-borne recorders from 1965 to 1968 in an area about 30km from the coast of Sheppey, where the sea floor was 12.1m deep, showed that the average wave height as 0.41m above the sea level and the maximum wave as 1.68m above the sea level. The maximum wave near the coastline was calculated using the measured sea level and the predicted tide, which is also called ‘extreme surge’. The extreme surge recorded at the tidal gauge station in Sheerness from (1990-2010) shows the maximum height of the surge is 2.95m and the average height is 0.86 m.
1965年至1968年由艦載錄像機面積從謝佩海底深12.1米的海岸約30公里的波數據記錄，結果顯示，平均波高海拔和最大波0.41米為海拔1.68米。

Flooding could be caused when a storm surge occurs near a high tide. Estimation of the change to storm surges and the extreme water levels over the next 100 years has been made in the UKCP09 document; for the Isle http://ukthesis.org/Thesis_Writing/Accounting_Assignment/Engineering/ of Sheppey coastal area, the model projection results show only a small change with a great deal of uncertainty. As such this change of storm surge level over the next 100 years will not be used in the design process. (32)
洪水發生風暴潮時，可能是由于附近一個高潮。估計風暴潮的變化，在未來100年極端水位已取得的UKCP09文件;

Relevance to construction
相關建設

By considering the extreme level of surge and sea level rise, the reclaimed land is planned to be a minimum of 5m above the mean sea level after full settlement occurred. Settlement and initial island height estimates are to be designed separately.
考慮潮和海平面上升，極端水平，填海所得的土地規劃為5m以上的最低平均海平面發生后全數清償。結算和初始島嶼的高度估計是單獨設計。

Existing sea defenses
現有的海上防御

Due to the location and geographical features of the Isle of Sheppey, many area near the coastline are in the intertidal zone – shown in Figure 26 - and many others at a high risk of flooding.
由于謝佩島的位置和地理特征，許多地區的海岸線附近的潮間帶 - 如圖26所示 - 和許多其他人在一個較高的水浸風險。

Current sea defenses around the Isle of Sheppey consist of a variety of structures. From West to East:
目前謝佩島附近的海上防御包括各種結構。從西到東：

• seawalls, revetments, groynes and recharge along Sheerness coast
• shingle embankments for protecting the Minster Marshes,
• seawalls, revetments and groynes at Minster;
• seawalls, revetments and groynes throughout Warden Bay;
• embankments towards Shell Ness;
• saltings and sand/shingle banks in Swale Estuary

 
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Figure 26

The Isle of Sheppey Strategy (initiated in 1998) was included in the coastal strategy developed by SECG (South East Coastal Group). It recommends improving the existing defences around the Northern and Western coasts, with further consideration for the Southern defences. However, no protection is deemed necessary around the cliff areas and from Minster to Warden Point. This plan for the future is shown in Figure 27.

Figure 27

Erosion    
侵蝕

 In 2005 the National Trust published research on the shifting of the coastline and its long-term future, considering the impact of erosion, flooding & sea level rise. However, the publication only indicates the ten coastlines in its care which face the highest risk of changing coastline; it does not include detailed results which can be adopted to assess the situation of our proposed site. Other studies have followed, such as on the South West England in 2008, by the National Trust, and detailed data on coastal erosion also can be obtained from IECS research in 1994 the North East of England. However it seems not much detailed data about the erosion in the Thames Estuary is readily available.
其他研究也緊隨其后，如2008年在英格蘭西南部，由國家信托，海岸侵蝕的詳細數據也可以IECS研究獲得1994年英格蘭東北部。然而，它似乎沒有太多詳細的數據在泰晤士河河口侵蝕更是一應俱全。

However, we must still conclude erosion is a risk to the new platform, and that construction of a breakwater may be required to protect the reclaimed land and runways from reducing the incident wave energy. Because the breakwaters are sited further out to the sea, they will be in an area with deeper water, where the attenuation by friction of sedimentation is less and the wave energy is higher than in reclaimed land. The breakwaters need to be design as enough tough to resist the full force of the waves. Without the full assessment for their location, the breakwaters can generate a negative effect on the reclaimed land (such as when an insufficient single breakwater generates the formation of a tombolo profile. For the common segmented breakwater, the ratio of the gap width to structure length and the ratio to distance from shore control the degree of effectiveness (35). Therefore careful investigations must be carried out in considering the construction of these protective measures.
然而，我們仍然必須斷定糜爛是一種新平臺的風險，減少入射光波的能量，可能會被要求保護的填海土地和跑道，建設防波堤。