An EPA program for monitoring ecological status and trends

Abstract

Despite hundreds of millions of dollars spent annually in the United States on environmental monitoring, policy and decision makers seldom have ready access to monitoring data to aid in prioritizing reasearch and assessment efforts or to assess the extent to which current policies are meeting the desired objectives. EPA is currently conducting research to evaluate options for establishing an integrated, cooperative monitoring program, with participation by federal, state, and private entities, that could result in annual statistical reports and interpretive summaries on the status and trends in indicators of adverse disturbance and corresponding 'health' of the nation's ecosystem on the regional and national scale.

Can we gain precision by sampling with probabilities proportional to size in surveying recent landscape changes in the Netherlands?

“…No geostatistical model need to be introduced to account for the sampling error, and the sampling variance of the estimated changes can be derived from the known pairwise inclusion probabilities as determined by the sampling design. For the same reasons the US Environmental Protection Agency (EPA) based the Environmental Monitoring and Assessment Programme (EMAP) on probability sampling (Messer et al 1991).…”

“…The networks focus on certain aspects of the environment such as the quality of the air, the surface water, the groundwater or the soil, the abundance of plant or animal species, biodiversity, abundance of ecologically important landscape elements such as hedgerows, etcetera. For instance, in the United States of America the Environmental Protection Agency (USEPA) started in the late eighties of the previous century the Environmental Monitoring and Assessment Programme (EMAP) (Messer et al 1991). The primary objective of EMAP is to estimate, with known confidence, the current status, extent, change and trends in indicators of the condition of the Nation's ecological resources -forests, arid lands, agroecosystems, wetlands, lakes, streams, Great Lakes, estuaries, and near-coastal systems.…”

Long-term strategy for the statistical design of a forest health monitoring system

“…Remeasurement of an interpenetrating subsample of plots can mitigate many of these problems. An interpenetrating subsample should be well distributed in space across the population (Messer et al, 1991). For example, consider a systematic sample of 300 plots on a triangular grid.…”

“…Some variables for a subsample of field plots are measured with the aerial photography or videography every 1 to 4 years; other variables are measured in the field every 4 to 16 years. The geometry of the triangular sampling grid permits incremental changes in sampling intensity, while maintaining even spacing of sample plots (Messer et aL, 1991).…”

“…Use interpenetrating sampling (Messer et al, 1991) or similar method so sampling intensity can be readily increased in time and space as needed.…”