摘要
Land reclamation has played a significant role in the urban development process in coastal areas in many countries.Over the last 20 years,land reclamation has gained much popularity especially along coastal areas of the south and east Chinadue to rapid development of industry and urbanization.While reclamation provides valuable land,it also creates variousengineering, environmental and ecological problems in coastal areas.The direct impact of land reclamation 0n coastalengineering,environment and marine ecology is well recognized and widely studied.However,it has not yet been recognizedthat reclamation may change the regional groundwater regime,including groundwater level,interface between seawater andfresh groundwater,and submarine groundwater discharge to the coast.There may be various chemical reactions between thefiIl materials and the marine mud.These processes may result in chemicals which may have adverse effect to the coastal Dlantsand organisms.This paper presents respectively two preliminary case studies about the possible modification of the regionalflow system at Penny’s Bay,Hong Kong due to land reclamation and the possible chemical reactions in the reclamation site atShekou,Shenzhen.This paper predicts the change of groundwater system around the bay area in response to the landreclamation and the possible pathway of the contaminated groundwater below Cheoy Lee Shipyard located on the north—eastern shores of Penny’s Bay.After reclamation the total groundwater head in the entire model area is increased.Due to thechange of the flow system after land reclamation,the contaminated groundwater near the shipyard will not spread out muchwithin Penny’s Bay,as many people expected,but migrate northeast toward the opposite coast.At the Shekou site,the fillmaterials,which are largely reddish or brown decomposed granitic rock excavated from nearby hills,are dumped over thegrey to dark marine mud at the sea bed.Because the coast line is extended seaward,the original seawater and groundwaterinterface will also move seaward accordingly.The alkaline seawater initially in the site will be gradually displaced by acidicgroundwater.It is hypothesized that various chemical and physical reactions will occur in the site.These reactions mavrelease chemicals which may have adverse effects OD coastal water quality and environment.However,further studies arerequired to investigate these hypotheses.