Detecting water quality responses to land management changes: Why is it so difficult?

ABSTRACT

Conducting successful research to relate land use practices to water quality at the watershed scale is difficult for many reasons, including lack of control of many aspects of the land use, time lags in watershed and water quality response to changes, and reluctance of funding agencies to fully implement the most powerful research design, the before-after paired-watershed design. Detecting water quality responses to changes in land management programs, which can be considered applied watershed-scale research experiments, is even more difficult. When adequate data are available, however, it is possible to document the success of land management programs, and to build the case that observed changes are responses to management actions, not coincidental changes due to other factors such as weather.