Modeling Erosion on Construction Sites

construction;calibration;validation;runoff;erosion;GIS;watershed;WEPP;GeoWEPP;BMP;sediment;riparian buffer

Moore, Amber Dawn ; Helena Mitasova, Committee Member,Greg Jennings, Committee Member,Keith Cassel, Committee Co-Chair,Rich McLaughlin, Committee Chair,Moore, Amber Dawn ; Helena Mitasova ; Committee Member ; Greg Jennings ; Committee Member ; Keith Cassel ; Committee Co-Chair ; Rich McLaughlin ; Committee Chair

University:North Carolina State University

关键词: construction;    calibration;    validation;    runoff;    erosion;    GIS;    watershed;    WEPP;    GeoWEPP;    BMP;    sediment;    riparian buffer;   

Others  :  https://repository.lib.ncsu.edu/bitstream/handle/1840.16/3122/etd.pdf?sequence=1&isAllowed=y

美国|英语

来源: null

【 摘 要 】

Our first objective was to develop suitable construction site parameters for the validated WEPP erosion prediction model. Predicted values were correlated with field observations for runoff and sediment yield. Runoff volumes and sediment yields similar to those measured on an active construction site were achieved by removing the A horizon from the soil input parameter and applying a landcover parameter with no ground cover and minimal roughness. Increasing critical shear stress to 384 Pa (as recommended by an erosion mat manufacturer) efficiently predicted runoff volume (E = 0.66) and sediment yield (E = 0.57) when compared to a construction site stabilized with straw, tar and erosion blankets. Our second and third objectives were to use to evaluate state-approved sediment traps and riparian buffers with WEPP and GeoWEPP, and to create erosion and sediment control scenarios that would achieve the NC water quality standard of 50 Nephlometric Turbidity Units. Two sediment traps on an actual school construction site were modeled with WEPP, and a 15.2 m width forest buffer on a planned golf course site was modeled with GeoWEPP. WEPP predicted average trapping efficiencies of sediment traps A and B to meet the NC standard of 70 % trapping efficiency. WEPP predicted runoff from sediment trap B met the turbidity standard for 11 % of the modeled storm events. GeoWEPP predicted that the riparian buffers would not meet the turbidity standard for any of the modeled storm events. The existing sediment controls were adjusted to meet water quality standards by increasing sediment trap size, replacing free-draining traps rock outlets with standing pools behind culvert outlets, extending the riparian buffer, and adding vegetation to highly erosive areas determined by GeoWEPP. Turbidity standards were met on watershed A by removing the outlet from the second sediment trap and increasing the trap area 6-fold. WEPP and GeoWEPP are useful for modeling construction sites and for designing erosion control scenarios, although the new parameters and the GeoWEPP model will need to be validated on other construction sites to improve confidence in the model output.