Starting from the early 1990s, the Chinese navy has invited the related experts to conduct exhaustive hydrological and geological freshwater exploration over 19 islets on the Xisha Islands.

• 从上个世纪90年代初期开始，海军多次邀请有关专家，对西沙淡水资源进行全面勘查，对19个岛礁进行了水文地质勘测。