Impact of Island Urbanization on Freshwater Lenses: A Case Study on a Small Coral Island

Freshwater resources on small coral islands mainly exist in the form of freshwater lenses. The lens is highly vulnerable to salinization due natural recharge variations and urbanization construction. However, it unclear how a evolves under influence construction which factors control its evolution. Based hydrogeological data island China, corresponding 3D numerical model was established by Visual MODFLOW software investigate formation evolution lenses conditions. Thereby, reclamation scenario impermeable surface were set up changes morphology volume analyzed. results show following: (1) After building, would reach stable state after 25 years also appear newly added part with thickness 9.5 m, while total increase 1.22 times that original island. (2) When built at different positions island, reduction lens, order from large small, Scenario B (northeast side), A (southwest side) C (central); area, gradually decrease more than 50% exceeding 30% area. study has important implications for conservation rational development subsurface islands.