Conceptual design of the surface water component of the national water quality assessment (NAWQA) program

Abstract

The U.S. Geological Survey started, in a pilot phase, a program to provide nationally consistant information on the status and trends in the quality of the Nation's fresh water and to identify and describe the relationships between both the status and trends in water quality as they relate to natural factors and the history of land-use and land-and waste-management practices. The program is organized into hydrologically based study units and, for the study of surface water, involves a combination of f ixed-station, synoptic and intensive study approaches. INTRODUCTIOM

STATISTICAL METHODS AND SAMPLING DESIGN FOR ESTIMATING STEP TRENDS IN SURFACE‐WATER QUALITY1

“…For surface-water quality, because of seasonality and flow effects, this snapshot (which also might be taken once per decade) requires at least a few years. This rotational approach is now being used on a pilot program basis in the U.S. Geological Survey National Water Quality Assessment Program (Hirsch, 1986;Rubin, 1987).…”