A GIS analysis of agricultural runoff potential in Wayne County, NC.

Abstract

MASON, CASSIDY RENA. A GIS analysis of agricultural runoff potential in Wayne County, NC. (Under the direction of Dr. Tamara Pandolfo). Wayne County, North Carolina is home to many row crop agriculture practices that rely on the Neuse River for fertile soils and water for irrigation. However, the water that flows off these agricultural areas from excess rainwater or irrigation can impact the quality of water flowing through the Neuse River. Agricultural runoff contains a variety of substances that can impact water health including pesticides, sediments, and excess nutrients. To determine areas where agricultural runoff has the most potential to impact the Neuse River water quality, a GIS analysis was conducted using a weighted sum calculation. An area with high potential for runoff was considered as such if the area was used for row crop agriculture, had a high slope percentage, and a fine soil texture. Wayne County consisted of 44.7% cultivated row crop land at the time the land classification was completed in 2016. The study area had an average slope of 1.42% with soils consisting of 46% loamy sand, 34% sandy loam, and 11% loam. This study concluded that only 2.6%, or 4219.8 acres, of row crop land in Wayne County, NC has a high potential to form agricultural runoff. Runoff management strategies are vital in preventing runoff legacy effects on water quality. Deep fertilizer placement and controlled-release fertilizers have been shown to reduce the amount of nutrient loading to water systems. Sediment transportation can be prevented and reduced by tillage strategies including conservation tillage, such as no-till and reduced tillage, and rotational tillage. These strategies reduce soil disturbances and cause less erosion and runoff of loose sediments. Water quality of the Neuse River must still be monitored even if runoff management strategies are implemented to ensure continued water health.