|Inamdar, Shreeram - VIRGINIA TECH|
|Altier, Lee - CAL STATE UNIV-CHICO|
|Thomas, Daniel - UNIV OF GEORGIA|
Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 27, 1999
Publication Date: June 1, 2000
Citation: INAMDAR, S.P., SHERIDAN, J.M., WILLIAMS, R.G., BOSCH, D.D., LOWRANCE, R.R., ALTIER, L.S., THOMAS, D.L. EVALUATION OF THE RIPARIAN ECOSYSTEM MANAGEMENT MODEL (REMM): I. HYDROLOGY. TRANSACTIONS OF THE AMERICAN SOCIETY OF AGRICULTURAL ENGINEERS. 42(6):1679-1689. 2000. Interpretive Summary: Research has shown that forest buffers located adjacent to streams, ponds, lakes and other sensitive wetland areas can reduce pollution by runoff from agricultural areas, improving the quality of the nation's surface and groundwater supplies. However, science-based guidelines are needed for design and management of riparian forest buffers. The Riparian Ecosystem Management Model (REMM) is a computer model that has been developed for simulation of the relative water-quality improvements resulting from riparian forest buffers. REMM simulates movement of surface and shallow subsurface water, sediment and nutrients, as well as plant growth within buffer areas, in response to varying weather conditions, plant species selection and buffer configuration and management. The REMM hydrology component provides information on water storage and movement required for simulation of physical, chemical and biological processes within riparian buffers. The hydrology component is tested using data from a riparian study site in the southeastern U.S. Computed surface flows and shallow groundwater depths were compared with 5 years of field data. Results show good correspondence between model simulations and field observations, indicating that the model component provides reasonable estimates of surface and shallow groundwater movement within buffer areas. Computed hydrologic budgets produced total streamflow estimates comparable to those observed for the buffer study area. This technology will provide natural resource and environmental quality personnel with the capability for developing effective riparian buffer design and management strategies for reducing nonpoint source pollution from agricultural areas.
Technical Abstract: The Riparian Ecosystem Management Model (REMM) was used to simulate shallow groundwater movement, water table depths, surface runoff, and annual hydrologic budgets for a coastal plain riparian forest buffer system near Tifton, Georgia, USA. The riparian buffer consisted of zone 3 (grass downslope from a row-crop field); zone 2 (mature pine forest downslope from zone 3); and zone 1 (mature hardwood forest downslope from zone 2 adjacent to stream). Measured surface runoff and shallow groundwater movement from the adjacent agricultural field were used as hydrologic inputs to REMM. Uncalibrated simulation results for a five- year period were compared to measured values for the same time period The overall error in zone 2 and zone 1 mean water table depths was about 70 mm, although absolute errors were higher. The water table dynamics simulated by REMM were similar to observed although lags were observed in the response of the simulated water table to large rainfall events. Mean simulated and observed surface runoff depths for the five year evaluation period agreed within one standard deviation. There was considerable variability in observed surface runoff depths, but simulated seasonal total depths of surface runoff produced similar temporal and spatial patterns as observed values. Annual hydrologic budgets produced total streamflow comparable to those estimated for the riparian buffer site. These results provide an adequate basis for subsequent testing of other REMM model components including water quality and nutrient cycling.