Modeling Erosion on Construction Sites

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.

Author dc:creator

• Moore, Amber Dawn

Advisors dc:contributor.advisor

• Helena Mitasova, Committee Member
• Greg Jennings, Committee Member
• Keith Cassel, Committee Co-Chair
• Rich McLaughlin, Committee Chair

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

Statement dc:rights

• I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.

Dc Identifier Other

etd-11042004-094907

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https://repository.lib.ncsu.edu/server/oai/request?verb=GetRecord&metadataPrefix=dim&identifier=oai%3Arepository.lib.ncsu.edu%3A1840.16%2F3122