USGS Water-Quality Data for the Nation - National Water Information System (NWIS)

The USGS compiles online access to water-resources data collected at approximately 1.5 million sites in all 50 States, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, American Samoa and the Commonwealth of the Northern Mariana Islands.美国地质调查局（United States Geological Survey, USGS）汇集了全美50个州、哥伦比亚特区、波多黎各、美属维尔京群岛、关岛、美属萨摩亚及北马里亚纳群岛联邦内约150万个监测站点采集的水资源数据，并提供这些数据的在线访问途径。