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REMOTE SENSING TOOLS ASSIST IN ENVIRONMENTAL FORENSICS PART II - DIGITAL TOOLS
Citation:
Brilis, G M., P. M. Stokely, R. J. Waasbergen, AND C. L. Gerlach. REMOTE SENSING TOOLS ASSIST IN ENVIRONMENTAL FORENSICS PART II - DIGITAL TOOLS. ENVIRONMENTAL FORENSICS 2(3):1-7, (2001).
Impact/Purpose:
The overall objective of this task is to provide the Agency with improved science guidance and strategies for more effective science management and administration.
Description:
This is part two of a two-part discussion, in which we will provide an overview of the use of GIS and GPS in environmental analysis and enforcement.
GIS describes a system that manages, analyzes and displays geographic information. Environmental applications include analysis of source, extent and transport of contaminants, nonpoint runoff modeling, flood control, and emergency response support. The ability to examine spatial relationships between environmental observations and other mapped and historical information, and to communicate these relationships to others, makes GIS valuable in environmental forensics. The US Environmental Protection Agency currently requires the inclusion of locational information with all other environmental data that is collected.
GIS is a complex tool that requires careful planning and design to be successfully implemented.
Choices in hardware, software and data development must be based on evaluation of project objectives, analytical requirements, data availability and data development considerations. Data sets must be evaluated and documented with metadata. The GPS (Global Position System) is a satellite based system that provides highly accurate, three-dimensional position information anywhere on the earth's surface. Using portable radio receivers, field analysts can easily record the positions of spill sites, sampling locations and other environmental features. Spatial accuracy of GPS ranges from 20-30 m (single receiver) to 1-5 meters (differential GPS) for navigation-grade instruments, and down to millimeter level accuracy for geodetic units. GPS can be used not only to capture spatial information into a GIS system, but also to evaluate and quantify the spatial accuracy of existing digital map data, and to provide control points for existing aerial photographs and other remotely-sensed data.