Spelling suggestions: "subject:"vegetated filter"" "subject:"vegetate filter""
1 |
Evaluation of vegetated filter strips for attenuation of pollutants resulting from military activitiesSatchithanantham, Sanjayan January 1900 (has links)
Master of Science / Department of Biological & Agricultural Engineering / Stacy L. Hutchinson / A field study was conducted at Fort Riley, Kansas from late spring to early winter of 2007 to investigate the ability of vegetated filter strips (VFS) to attenuate pollutants resulting from military activities, the impact of different management practices (i.e. burning and mowing) on VFS performance, and the effects of vegetation on hydrological components of VFS, especially infiltration and runoff. Two native tallgrass VFS sites, each comprising three plots, located in the military training area of Fort Riley were used for this study. Fifteen rainfall events were simulated on each site along with overland application of water containing nitrogen (N), phosphorous (P) and sediment. At the end of the season both VFS were managed by mowing or burning and a final rainfall simulation was done.
Variables including rainfall, infiltration, runon, runoff, above ground biomass density, pollutant concentrations of runon and runoff, and soil moisture were measured and used in the data analysis. Hydrograph development, water balance, and mass balance calculations were carried out in order to calculate the pollutant trapping efficiencies (PTE) of the VFS. Statistical analysis was done by fitting several regression models. Mean comparisons were also done for variables and variance was decomposed into time, plot and site effects at an alpha = 0.05.
Results showed that on average the VFS attenuated 84 % of total nitrogen, 24 % of total phosphorous and 95 % of sediments. Regression models showed that infiltration percentage and biomass density have a positive correlation with PTE. Runoff volume and PTE were negatively correlated. Soil moisture was negatively correlated with infiltration and time to runoff. With increasing biomass density, percentage of water infiltrating and time of concentration increased. Management practices, especially burning, tended to reduce PTE. Also, both management practices reduced infiltration percentage and time of concentration. PTE reduced with intensifying rainfall and increased when rainfall faded off. Phosphorous was the most sensitive pollutant for intense storm conditions followed by nitrogen, while sediment was comparatively insensitive.
|
2 |
EVALUATION OF VEGETATED FILTER STRIP IMPLEMENTATIONS IN DEEP RIVER PORTAGE-BURNS WATERWAY WATERSHED USING SWAT MODELLinji Wang (5930996) 16 January 2019 (has links)
In 2011, the Deep River Portage-Burns Waterway Watershed was identified as a priority in the
Northwest Indiana watershed management framework by the Northwester Indiana Regional
Planning Committee. 319 grant cost-share programs were initiated in effort of maintaining and
restoring the health of Deep River Portage-Burns Waterway Watershed. A watershed management
plans have been developed for this watershed which proposed the implementation of vegetated
filter strips (VFS) as an option. In this thesis work, the effectiveness of VFS as a best management
practice (BMP) for the Deep River system was evaluated using a hydrological model scheme. <div><br></div><div>In this research, a Nonpoint Source Pollution and Erosion Comparison Tool (NSPECT) model and
a Soil Water Assessment Tool (SWAT) model were constructed with required watershed
characteristic data and climate data. The initial hydrologic and nutrient parameters of the SWAT
model were further calibrated using SWAT Calibration and Uncertainty Programs (SWAT_CUP)
with historical flow and nutrient data in a two-stage calibration process. The calibrated parameters
were validated to accurately simulate the field condition and preserved in SWAT model for
effectiveness analysis of BMP implementations. </div><div><br></div><div>To evaluate the effectiveness of VFS as a BMP, four different scenarios of VFS implementations
along the Turkey Creek was simulated with the calibrated SWAT model. With the implementation
of VFS in the tributary subbasin of Turkey Creek, the annual total phosphorus (TP) of the VFS
implemented subbasin was reduced by 1.60% to 78.95% and the annual TP of downstream
subbasins were reduced by 0.09% to 55.42%. Daily percentage of TP reductions ranged from 0%
to 90.3% on the VFS implemented subbasin. Annual TP reductions of the four scenarios ranged
from 28.11 kg to 465.01 kg.<br></div>
|
3 |
Evaluation of Pond/Wetland/Vegetative Filter System to Treat Beef Manure Pile and Outdoor Confinement Area RunoffMejia Franco, Maria Juliana 10 December 2018 (has links)
Regulations with respect to the storage and handling of animal waste by livestock operations state that no person shall keep animals in a permanent confinement area unless there is a nutrient management strategy. Various studies indicate that constructed wetlands and vegetative filters are effective add-on technologies to supplement the treatment provided by conventional sedimentation pond systems in livestock operations. Seven months of data from a Pond/Wetland/Vegetative Filter system receiving cattle feedlot runoff were used to i) evaluate its efficiency removing organic matter, solids and nutrients from water, (ii) quantify constructed wetland kinetic removal rates described by the P-C-k model and examine the impact of temperature, (iii) evaluate and compare the performance of a two types of vegetative filter systems at different hydraulic loading rates; and (iv) recommend an optimum management option with design loading for beef producers. Results indicate that the effect of isolated rain events on the performance of the wetland showed to be contingent on the intensity of the event, former humidity conditions of the feedlot and the hydraulic capacity of the wetland. This experiment suggests that even relatively small VFSs or short FPs can markedly improve quality of runoff from livestock operations, and that it is possible to achieve significant mass and concentration removals if they are properly operated and maintained in conjunction with a pre-treatment system. The Pond/Wetland/Vegetative Filter system was effective at reducing Chemical Oxygen Demand COD (+92%), Total Phosphorus (+93%), Orthophosphate as P (+91%), Total Inorganic Nitrogen (+96%), Ammonia as N (+97%) and Nitrate as N (+82%) from manure and exercise yard runoff, providing a cost-effective treatment option for beef producers.
|
Page generated in 0.2082 seconds