[1]TIAN Yaowu,WANG Ning,LIU Jing.Analysis of Simulation Error of Runoff and Sediment for Taowan Watershed in Funiushan Mountain Area[J].Research of Soil and Water Conservation,2016,23(05):56-62.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
23
Number of periods:
2016 05
Page number:
56-62
Column:
Public date:
2016-10-28
- Title:
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Analysis of Simulation Error of Runoff and Sediment for Taowan Watershed in Funiushan Mountain Area
- Author(s):
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TIAN Yaowu, WANG Ning, LIU Jing
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College of Forestry, He’nan University of Science and Technology, Luoyang, He’nan 471003, China
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- Keywords:
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AnnAGNPS model; runoff; sediment; Funiushan Mountain area; simulation
- CLC:
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S157;P333
- DOI:
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- Abstract:
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A typical watershed, Taowan, was selected as the study site, and the main goal was to evaluate the performance of AnnAGNPS Model in simulating runoff, sediment loading and nutrient loadings under the conditions of Funiushan Mountain area, and analyze the influencing factors of the simulation error. The data of 22 events of runoff and sediment in the watershed during the period from 2006 to 2007 were used to calibrate the model and the data of 31 events during the period from 2008 to 2009 were used for validation purposes. The whole evaluation consisted of determining the coefficient of determination (R2), Nash-Sutcliffe coefficient of efficiency (E), and the percentage volume error (VE). Most of model input parameters were sourced from Luoyang Forestry Bureau field observations and experiments. Results showed that: (1) runoff was undersimulated by -7.7% with R2 of 0.95 (p < 0.05) during calibration period (2006—2007) and undersimulated by -6.1% with R2 of 0.90 (p < 0.05) during validation period (2008—2009), factors affecting runoff simulation errors were accuracy of values for the SCS-CN, the results of runoff simulation also affected the other objects, which may be the reason of relatively low error of runoffs, the model simulated runoff within the range of acceptable accuracy (< ±15%); (2) the model oversimulated the event-based sediments by 15.1% with R2 of 0.55 (p < 0.05) during calibration period (2006—2007) and 17.0% oversimulated with R2 of 0.60 (p < 0.05) during validation (2008—2009), factors affecting sediment simulation error are more complex. Vegetation coverage and Manning roughness coefficient were most sensitive to the sediment simulation errors. And it was also affected by the scales of spatial parameter accuracy such as watershed DEM, soil and land uses. The trend of sediment simulation errors was similar to runoff. For the events of small magnitude, the model generally oversimulated them, while the opposite was true for larger events. Nitrogen was oversimulated by 22.0% with R2=0.69 (p < 0.05), and phosphorus was oversimulated by 24.0% with R2=0.48 (p < 0.05). In general, the model performs well in simulating runoff compared to sediment and nutrients. As a watershed management tool, it can be used under the conditions of Funiushan Mountain area after proper calibration.