Initial Analyses of Change Detection Capabilities and Data Redundancies in the Long Term Resource Monitoring Program

摘要

Evaluations of Long Term Resource Monitoring Program sampling designs for water quality, fish, aquatic vegetation, and macroinvertebrates were initiated in 1999 by analyzing data collected since 1992 in six trend analysis areas. Initial emphasis was placed on evaluating statistical power to detect change from one year or sampling interval to the next, and on determining what spatial, methodological, or target variable redundancies existed in the data Sets. Power to detect change was evaluated at halved, present, and doubled levels of effort. Power to detect change for different variables varied widely and was greatly influenced by sample size and for species by their frequency of occurrence. Power for detecting annual and seasonal changes in most water quality variables seems adequate. A doubling of effort would provide little increase in power, and some reduction or redistribution of effort may be possible.