Nonpoint Source Pollution and Erosion Comparison Tool (N-SPECT)
The Nonpoint Source Pollution and Erosion comparison Tool (N-SPECT) is a complex yet user-friendly geographic information system (GIS) extension that helps coastal managers and local decision makers predict potential water-quality impacts from nonpoint source pollution and erosion. Users first enter information about their area (land cover, elevation, precipitation, and soil characteristics) to create the baseline information. They can then add different land cover change scenarios (such as a development) to get information about potential changes in surface water runoff, nonpoint source pollution, and erosion. It is maintained by the NOAA Coastal Services Center.
N-SPECT was initially developed as a decision-support tool for coastal managers in Hawaii and has since been applied in coastal areas around the U.S., the Caribbean, Central America, and the South Pacific. It operates most effectively in medium-to-large watersheds having low-to-moderate topographic relief. Studies have shown that N-SPECT tends to over predict sediment delivery in regions having extreme precipitation regimes and very steep slopes, so users are strongly encouraged to account for these potential sources of error during the course of sediment delivery analyses.