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STATISTICAL PROPERTIES OF DESIGNS FOR SAMPLING CONTINUOUS FUNCTIONS IN TWO DIMENSIONS USING A TRIANGULAR GRID
Citation:
Overton, W. AND S. Stehman. STATISTICAL PROPERTIES OF DESIGNS FOR SAMPLING CONTINUOUS FUNCTIONS IN TWO DIMENSIONS USING A TRIANGULAR GRID. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/3-90/095.
Description:
The U.S. Environmental Protection Agency's (EPA) Environmental Monitoring and Assessment Program (EMAP) is a current initiative designed to identify and bound the extent, magnitude, and location of degradation or improvement in environmental condition. he proposed monitoring design involves sampling resources systematically via a triangular grid that is overlaid on the United States. his grid is applied in different ways to sample-different types of resources. or continuous resources, such as extensive waterbodies, the observations may be point measurements of the response variable, as for example, alkalinity of the Great Lakes. The specific problem investigated in this paper is motivated by design considerations for open-water sampling in the estuary component of the Near Coastal resource. tatistical properties of two sampling design alternatives imposed on the triangular grid are explored, and contrasted to a third design that does not use the grid. he three designs were evaluated on the criteria of precision and suitability of variance estimation, by a mixture of analysis and simulation. he surface models used throughout the evaluation to explore properties of the designs were planar, quadratic and sinusoidal.