A DATABASE ON WATER-QUALITY OF THE MISSISSIPPI RIVER

A water quality GIS/database has been developed for the Mississippi Ri ver within the state of Louisiana. Existing ambient water quality data (1.3 million records) and records of river stage and discharge for th e river and its tributaries have been acquired from government agencie s, industry, and research projects. Data were initially reviewed to va lidate information quality. They have been incorporated into an Oracle (R) database created to provide rapid data searches and retrieval of i nformation through a menu-format user interface. Descriptive informati on about sample collection and analysis methods are included as well a s government advisory criteria which provide ecological and human heal th Perspectives to assist in data interpretation. GIS software utilize s electronic base maps which have been developed in Arc/Info(R) and Ar cView(R) data formats to generate geographic displays and graphical re presentations of the data. Examples of the capabilities of the system are included for data on mercury, phosphates, and nitrates. The tempor al trends in the concentrations of rep resentative water quality param eters are tabulated for a selected segment of the river.