Riparian Buffer Project

The goal of the riparian buffer project is to demonstrate the use of riparian buffers in protecting water quality, enhancing the wildlife and aquatic habitat. A grant was awarded to Biological and Agricultural Engineering department and the water quality group (WQG) to monitor the subset of riparian buffers implemented in the NC-CREP (North Carolina Conservation Reserve Enhancement program). At the beginning of the project, 4 riparian buffer sites were selected to monitor for water quality and habitat. These sites were chosen based on a few parameters such as landscape position, width, up slope pollutant source, hydrology (i.e. no ditches or tile drains through the buffer).

Finally three riparian buffers sites that were selected based on above parameters are located in Halifax County North Carolina and are being monitored for their water quality improvement, nutrient and sediment reduction from 2005-2009 and monitoring will be continued until 2010. Prior to site instrumentation, benthic macro-invertebrates studies were performed at two sites and vegetation survey was done at all three buffer sites where water quality monitoring is currently being conducted. The three buffer sites have been instrumented in 2005 with water quality and water table monitoring wells in all the three buffer sites. Daily water tables profiles are being monitored in all three buffer sites with monthly ground water sampling for nitrate-nitrogen, ammonium, total phosphorus, dissolved organic carbon etc with monthly redox measurements taken as well.

The objective of the research is to evaluate the effectiveness of these buffers by monitoring water quality and water table data and then using the field data to statistically analyze the reduction capacity of these buffers for the nutrient and sediment loads reduction to the streams. The field data collected from two buffer sites for total period of 6 years will be used for modeling the groundwater hydrology and nitrate dynamics using the REMM model (Riparian Ecosystem Management Model) designed at USDA-ARS (Lowrance et al., 2000). The model will be used to predict the long term performance of these buffers enrolled in the CREP and ultimate goal would be to simplify the model and make it user friendly for field personnel such as NC- CREP to make quick assessment of buffers.

From 2005-2009, the BAE NCSU department and water quality group (WQG) consisting of two technicians from WQG, five graduate students and four faculty members have been working on this NC-CREP project. The goal of this riparian buffer project is enhance the understanding behind the use of riparian buffers in protecting the water quality and laying out the factors or parameters that affect the success of riparian buffers for improving water quality. The REMM model will be used as tool understand the complex physical system of the riparian buffers and make long term predictions of riparian buffer performance in terms of nitrate attenuation. Results from the field data and the modeling results will be used to make recommendations and provide guidelines for the field personnel such as NC-CREP to enhance the success of future riparian buffer installations in North Carolina.

Progress so far

Successfully collected and analyzed 56 months of water table and water quality data at three riparian buffer sites (2005-2009)

Analyzed soil cores for particles size analysis, denitrification enzyme activity and total soil carbon, nitrogen and phosphorus and plant litter for total carbon, nitrogen and phosphorus analysis on two buffer sites.

Successfully ran the REMM model on two riparian buffer sites for a period of four years from (2005-2008). This four year REMM modeling results are the un-calibrated results.

Upcoming tasks

Continue monitoring water quality and hydrology i.e. water table data at three riparian buffer sites.

Perform more soil sampling for particle size analysis, total carbon, nitrogen, phosphorus and for analyzing the denitrification enzyme activity (DEA) at the two buffer sites.

Calibrate the model on two riparian buffer sites and simulate the long term performance of riparian buffers in terms of nitrate attenuation.

For more information on these buffers and modeling contact Dr Mike Burchell or the graduate students on the graduate students webpage.