Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 26, 2001
Publication Date: August 1, 2001
Citation: Gerwig, B., Stone, K.C., Williams, R.G., Watts, D.W., Novak, J.M. 2001. Using GLEAMS and REMM to estimate nutrient movement from a spray field and through a riparian forest. Transactions of the ASAE. 44(3):505-512. Interpretive Summary: Pollution of the nation's streams and ground water is a national concern and agricultural nonpoint source pollution has been a major water quality concern. These concerns have been intensified in areas where concentrated cropping and animal production occur. Streams can be protected from nonpoint source pollution by riparian forest buffers. These riparian forest buffers remove nonpoint source pollution from water before it enter a stream. In a North Carolina watershed, a project was initiated to replant a riparian forest buffer that had been destroyed. The riparian forest was located between a small stream and a swine wastewater spray field. The replanted riparian forest will take many years to grow to maturity. To investigate the potential improvements in water quality that the riparian forest may produce, a computer model was used to simulate the study site. The GLEAMS model was used to simulate the swine wastewater spray field. A new model, the Riparian Ecosystem Management Model (REMM), was used to simulate the riparian forest. GLEAMS simulation results were used as input data for the REMM model. Both models simulated nitrogen in the soil and ground water in close agreement with observed data. The REMM model simulated trends in phosphorus data in good agreement with the observed data. The REMM model has great potential in helping action agencies and technical specialists in designing riparian forest buffers to protect our water resources.
Technical Abstract: With the increase in the number of large animal production facilities in eastern North Carolina, nutrient accumulation is becoming a problem in surface waters and groundwater. To protect these water sources, management practices to reduce nutrient movement or accumulation are being evaluated using computer models. The computer models, Groundwater Loading Effects of fAgricultural Management Systems model (GLEAMS) and a pre-release version o Riparian Ecosystem Management Model (REMM), were used to estimate nitrogen and phosphorus transport of nutrients through a riparian buffer zone from an agricultural field that received swine lagoon effluent. The models simulated annual application rates of effluent equivalent to 560 and 1000 kg N/ha. The GLEAMS model provided the weather data and nutrient concentrations in the soil, sediment, and leachate as input into REMM. GLEAMS monthly average NO3-N leachate concentrations for the 1000 kg N/ha loading rate were within 14% of the observed data, and the REMM model simulated NO3-N in the leachate within 5% of the observed data. Both models provided an adequate estimation of the nitrogen transport through the system. GLEAMS simulations of PO4-P leachate followed the general trend of observed data. However, there was very little difference in PO4-P concentrations between the two loading rates indicating a problem in the phosphorus calculations in the model. REMM simulated PO4-P leachate values were greater than observed concentrations and were affected by the inputs obtained from GLEAMS. The pre-release version of REMM provided good estimates of the nutrient transport, and with a few improvements, official releases of REMM have the potential to provide better estimates of the nutrient movement through the riparian buffer zone.