西沙群岛环境水文特征

Environmental Hydrologic Features of the Xisha Archipelago

西沙群岛地处热带，高温多雨，四周为海洋，由珊瑚堆积而成，并经一次地壳下沉运动后，再经上升运动而形成现代地貌形态．岛屿面积小，水文特征特殊，地表没有较大的贮水体，地表径流一般难形成，深部地下水常与海水相沟通，淡水资源十分缺乏．如何改善水文状况，提供淡水资源，促进生态环境改善。

The Xisha archipelago is located in tropical regions.It is sultounded by oceans and with a climate of high in temperature and plenty in rainfall.The islands are composed of coral reefs,whose modem landforms are developed after a subside in tectonic movement and an uplift followed.Islands are narrow in area.Particular environment developes particular hydrology which is characterised by that surface water storages are rare,surface runoff is difficult to develope and deep groundwater is connected with salt water,thus fresh water resource is scarece thought rainfall is abundant.With the increasing human activities,questions are brought out for island development such as how to imporove hydrologic conditions so as to provide enough fresh water resource,to improve the ecosystem and to keep continuous developement for environment and economic.