An Introduction to Identifying Nonpoint Sources of Water Pollution Using a Modified Land Use Conflict Analysis Identification Strategy (LUCIS) Model, Non-point Source Identification Strategy: NPSIS

Abstract

This paper examines the Non-Point Source Identification Strategy (NPSIS); a modification of the Land Use Conflict Identification Strategy (LUCIS): NPSIS is a raster model useful for identifying non-point sources of water pollution from three known contributors (agriculture, domestic, and natural background). By using a standard operating procedure, developers are able to create standardized datasets useful for identifying non-point sources of water pollution throughout the contiguous United States. The NPSIS model process requires the use of three “non-point source water pollution” contributors. A contributor is termed as a Non-Point Category (NPC) that contains collective elements (i.e. nutrient applications for agricultural purposes and urban runoff from highly developed areas). Using a survey, water resource professionals familiar with chosen study areas rank each NPC element according to potential impact to water quality. Following the survey, raster datasets that represent each NPC and impact to water quality are created using a lowest to highest (“1-9”) ordinal rank system derived from survey results after which each dataset is normalized using a (“1-3”) ordinal rank. Finally, the normalized NPC datasets are combined into one final model useful for identifying each dominant NPC by rank and location within a specified USGS watershed. In conclusion, the modifications to the LUCIS method yields results beneficial for identifying non-point source loads of water pollution.