The effects of urbanization on watershed functions: The relationship between impervious surface area and water quality in Cache County, Utah.

摘要

The percent of impervious surface area (ISA) is increasingly used as an important indicator of cumulative urban water resource impacts. This study tested the relationship between percent ISA and water quality in a semiarid environment. Satellite data were used to compute percent ISA in urbanizing northeast Utah. Water chemistry and discharge data were collected from canals during five stormwater runoff events. Variables measured included dissolved metals, nutrients, sediment, oil and grease, fecal coliforms, and field parameters. Percent ISA was calculated for eight contributing basins (sampling locations). Results of linear regressions correlating mean site concentrations and percent ISA were positive (p 0.03) for many variables, including total phosphorus (r2 = 0.86) and lead (r2 = 0.96). This study demonstrates that percent ISA is a useful indicator of cumulative water quality impacts. The ease of mapping percent ISA coupled with these findings suggest that ISA will be an important planning tool for protecting sensitive waters.