Synthesis of Design Guidelines and Experimental Data for Water Quality Function in Agricultural Landscapes in the Intermountain West

................................................................................................................................................... ii Preface...................................................................................................................................................... 1 Background .............................................................................................................................................. 2 Project Goal ............................................................................................................................................. 3 Methods.................................................................................................................................................... 4 Characteristics of the Study Area............................................................................................................. 4 Buffer Complexity and Dynamics ........................................................................................................... 5 Nutrient Cycling .......................................................................................7 Landscape Attributes Influencing the Effectiveness of Riparian Buffers; Implications for the Intermountain West .................................................................................................7 Primary Attributes.............................................................................................................7 Buffer Width.............................................................................................7 Slope Gradient..........................................................................................7 Soil Infiltration .........................................................................................8 Surface Roughness ...................................................................................8 Slope Length (Discussion) .......................................................................8 Adjacent Land Use Practices....................................................................8 Secondary Attributes..........................................................................................................8 Differences Between Arid and Non-Arid Riparian Systems ..................................................................9 Climate .....................................................................................................9 Hydrology.................................................................................................9 Soils........................................................................................................10 Topography.............................................................................................10 Vegetation...............................................................................................10 Wildlife...................................................................................................11 Sources and Causes of Impairment........................................................................................................11 Contaminants and Buffer Effects ...........................................................................................................13 Particulate Contaminants -Sediment......................................................................................................13 Reasons for Concern ...............................................................................13 How Buffers Affect Sediment .................................................................14