REMOTE SENSING AND GIS-ASSISTED ANALYSES OF LAND USE PATTERNS AND THEIR AFFECTS ON STREAMS IN WEST GEORGIA

The need for a land-use nutrient load analysis as part of the West Georgia Watershed Assessment requires up-to-date classifications of land-use patterns in Carroll and Heard Counties, Georgia. Using ERDAS Imagine 8.5, a supervised classification was conducted using Landsat Thematic Mapper Imagery from September 2001. Results were field checked for accuracy. The newly classified land-use maps were then imported into ESRI ArcView 3.2. Using the hydrologic analysis extension, calculations were performed to determine the percentage of land-use types contributing to sample stations within select watersheds of the two counties. Statistical analysis methods are applied to determine possible contributing variables to nutrient concentrations at these sites. Nutrients of interest include nitrite-nitrate-N, ammonia, TKN, and phosphorus. Preliminary analysis shows that concentrations of nitrite-nitrate-N, ammonia, and TKN show little to no significant correlation with time of sampling event or rainfall. However, elevated concentration levels of these nutrients are present in urbanized areas. Some of the highest nutrient concentrations noted are from a sample site located downstream of a wastewater treatment plant. Maximum values at this site include 2.14 mg/L, 3.80 mg/L, and 5.85 mg/L for nitrite-nitrate-N, ammonia, and TKN levels, respectively. Phosphorus concentrations show significant correlation with rainfall data. Sixty-seven and sixteen percent of the variability in the concentration could be explained at the 99% confidence level for sites HPG-21 and CTL-63, respectively. Other sites in the study show a significant correlation at the 95% confidence level. There is no apparent relationship in phosphorus concentrations and land-use patterns. The results of this project will prove helpful in assisting local governments with land-use management policies and educating the community about our watersheds.