Effects of critical source area on sediment yield and streamflow

The spatial discretization scale determines the degree to which the spatial heterogeneity of the surface condition and the stream network can be represented. Discretization scale can have a significant impact on watershed model results, with respect to both hydrology and water quality. The impact of critical source area (CSA) on simulated water yield for each cell can be assessed for streamflow and run‐off using the Annualized Agricultural Non‐Point Source (AnnAGNPS) model. The total number of cells simulated for the six watersheds ranged from 8 to 352 for various CSA combinations. Increasing the number of subwatersheds increased water and sediment yield in many watersheds. Increasing the number of cells influences the depiction of land use and soil type accordingly and therefore influences run‐off. The applied CSAs were also compared with topographic parameters such as average cell slope, average channel slope and length to width ratio of each watershed.

[1]  Jeffrey G. Arnold,et al.  Soil and Water Assessment Tool Theoretical Documentation Version 2009 , 2011 .

[2]  E. H. Goulding,et al.  by automated , 2008 .

[3]  Darius J. Semmens,et al.  The Automated Geospatial Watershed Assessment tool , 2007, Environ. Model. Softw..

[4]  Mukand S. Babel,et al.  Evaluation of annualized agricultural nonpoint source model for a watershed in the Siwalik Hills of Nepal , 2006, Environ. Model. Softw..

[5]  Mazdak Arabi,et al.  ROLE OF WATERSHED SUBDIVISION ON MODELING THE EFFECTIVENESS OF BEST MANAGEMENT PRACTICES WITH SWAT 1 , 2006 .

[6]  D. Scott Mackay,et al.  Effects of distribution-based parameter aggregation on a spatially distributed agricultural nonpoint source pollution model , 2004 .

[7]  R. Govindaraju,et al.  Effect of geomorphologic resolution on modeling of runoff hydrograph and sedimentograph over small watersheds , 2003 .

[8]  Jeffrey G. Arnold,et al.  EFFECT OF WATERSHED SUBDIVISION ON SWAT FLOW, SEDIMENT, AND NUTRIENT PREDICTIONS 1 , 2002 .

[9]  Philippe Marcoul,et al.  Effect of Watershed Subdivision on SWAT Flow, Sediment, and Nutrient Predictions , 2002 .

[10]  D. S. Mackay,et al.  Impact of subwatershed partitioning on modeled source- and transport-limited sediment yields in an agricultural nonpoint source pollution model , 2001 .

[11]  E. Gabet.  Gopher bioturbation: field evidence for non-linear hillslope diffusion. , 2000 .

[12]  D. Mackay,et al.  Impacts of input parameter spatial aggregation on an agricultural nonpoint source pollution model , 2000 .

[13]  Sudhakar Mamillapalli,et al.  Effect of spatial variability on river basin stream flow modeling , 1998 .

[14]  E. Keller,et al.  HYDROLOGICAL RESPONSE OF SMALL WATERSHEDS FOLLOWING THE SOUTHERN CALIFORNIA PAINTED CAVE FIRE OF JUNE 1990 , 1997 .

[15]  Raghavan Srinivasan,et al.  Effect of watershed subdivision on simulation runoff and fine sediment yield , 1997 .

[16]  D. Montgomery,et al.  Digital elevation model grid size, landscape representation, and hydrologic simulations , 1994 .

[17]  Baxter E. Vieux,et al.  Closure of "Nonpoint-Pollution Model Sensitivity to Grid-Cell Size" , 1993 .

[18]  C. T. Haan,et al.  Impact of Subdividing Watersheds on Estimated Hydrographs , 1993 .