Sediment measurement and transport modeling: impact of riparian and filter strip buffers.

Well-calibrated models are cost-effective tools to quantify environmental benefits of conservation practices, but lack of data for parameterization and evaluation remains a weakness to modeling. Research was conducted in southwestern Oklahoma within the Cobb Creek subwatershed (CCSW) to develop cost-effective methods to collect stream channel parameterization and evaluation data for modeling in watersheds with sparse data. Specifically, (i) simple stream channel observations obtained by rapid geomorphic assessment (RGA) were used to parameterize the Soil and Water Assessment Tool (SWAT) model stream channel variables before calibrating SWAT for streamflow and sediment, and (ii) average annual reservoir sedimentation rate, measured at the Crowder Lake using the acoustic profiling system (APS), was used to cross-check Crowder Lake sediment accumulation rate simulated by SWAT. Additionally, the calibrated and cross-checked SWAT model was used to simulate impacts of riparian forest buffer (RF) and bermudagrass [ (L.) Pers.] filter strip buffer (BFS) on sediment yield and concentration in the CCSW. The measured average annual sedimentation rate was between 1.7 and 3.5 t ha yr compared with simulated sediment rate of 2.4 t ha yr Application of BFS across cropped fields resulted in a 72% reduction of sediment delivery to the stream, while the RF and the combined RF and BFS reduced the suspended sediment concentration at the CCSW outlet by 68 and 73%, respectively. Effective riparian practices have potential to increase reservoir life. These results indicate promise for using the RGA and APS methods to obtain data to improve water quality simulations in ungauged watersheds.

[1]  J. Newbold,et al.  Water Quality Functions of Riparian Forest Buffers in Chesapeake Bay Watersheds , 1997, Environmental management.

[2]  John R. Williams,et al.  Sediment yield prediction based on watershed hydrology. , 1977 .

[3]  Bradley M. Crowder,et al.  Economic costs of reservoir sedimentation: A regional approach to estimating cropland erosion damage , 1987 .

[4]  J. Nash,et al.  River flow forecasting through conceptual models part I — A discussion of principles☆ , 1970 .

[5]  Jeffrey G. Arnold,et al.  Model Evaluation Guidelines for Systematic Quantification of Accuracy in Watershed Simulations , 2007 .

[6]  Patrick J. Starks,et al.  Environmental effects of agricultural conservation: A framework for research in two watersheds in Oklahoma's Upper Washita River Basin , 2008, Journal of Soil and Water Conservation.

[7]  D. N. Moriasi,et al.  Spatial resolution effect of precipitation data on SWAT calibration and performance: implications for CEAP. , 2009 .

[8]  S. J. Smith,et al.  Water quality impacts associated with sorghum culture in the southern plains , 1991 .

[9]  J. Arnold,et al.  Advances in the application of the SWAT model for water resources management , 2005 .

[10]  John R. Williams,et al.  LARGE AREA HYDROLOGIC MODELING AND ASSESSMENT PART I: MODEL DEVELOPMENT 1 , 1998 .

[11]  P. Allen,et al.  Multifrequency Acoustic Profiling for Water Reservoir Sedimentation Studies , 1999 .

[12]  Jeffrey G. Arnold,et al.  The Soil and Water Assessment Tool: Historical Development, Applications, and Future Research Directions , 2007 .

[13]  A. Simon,et al.  Disturbance, stream incision, and channel evolution: The roles of excess transport capacity and boundary materials in controlling channel response , 2006 .

[14]  Soroosh Sorooshian,et al.  Status of Automatic Calibration for Hydrologic Models: Comparison with Multilevel Expert Calibration , 1999 .

[15]  Mark D. Tomer,et al.  Quantifying relative contributions from sediment sources in Conservation Effects Assessment Project watersheds , 2008, Journal of Soil and Water Conservation.

[16]  S. Bennett,et al.  Texture, spatial distribution, and rate of reservoir sedimentation within a highly erosive, cultivated watershed: Grenada Lake, Mississippi , 2005 .

[17]  J. Colletti,et al.  Riparian forest buffers in agroecosystems – lessons learned from the Bear Creek Watershed, central Iowa, USA , 2004, Agroforestry Systems.

[18]  A. Simon,et al.  Relative magnitudes and sources of sediment in benchmark watersheds of the Conservation Effects Assessment Project , 2008, Journal of Soil and Water Conservation.

[19]  F. E. Dendy.  Distribution of Sediment Deposits in Small Reservoirs , 1982 .