IMPACT OF ROADS AND TRAFFIC ON WATER QUALITY IN ATLANTA METROPOLITAN AREA, USA

Non-point urban runoff is the major cause of stream impairment in the Atlanta Metropolitan Area, USA. As a major part of the cause, the contribution from anthropogenic activities associated with roads and traffic to water pollution is expected to increase due to the rapid population growth and urban sprawl. However, their impact on water quality has not received much attention from the state and local watershed management plans, and not been studied well elsewhere either. This project studies the impact of roads and traffic on water quality in the watersheds of the study area using GIS (Geographic Information System) and statistical analyses. GIS analyses are used to delineate watersheds using Digital Elevation Models for water quality sampling sites and to derive road and traffic indicators such as Road Density and Vehicle Miles Traveled (VMT), and other factors for each watershed. Statistical analyses are used to examine, quantify, and compare the relationships between water quality parameters (e.g. Specific Conductance) at sampling sites and the road/traffic indicators of the watersheds. The results show that roads and traffic have significant positive relationships with the concentrations of water quality indications. In other words, a high density of roads and traffic in watersheds is associated with a high concentration of water pollutants. This study will contribute to a better understanding of the impact of roads and traffic on water quality, and provide useful information for watershed management, transportation planning, and land use planning.