The agricultural industry in the United States has seen unprecedented growth in productivity and changes in industry structure. However, some negative environmental effects have emerged related to nitrogen, phosphorous, and sediment runoff. This study developed a novel, community economic systems methodology called the Biophysical and Economic Simulation of Agricultural Production (BESAP) model. This analyzed the economic tradeoff between farm and community level impacts associated with potential water quality standards for mitigating runoff in Mississippi. Key findings include: 1) farm-level net returns decrease with more stringent conservation practices to reduce nutrient runoff; 2) reductions in farm-level net returns have greater indirect cost effects on input suppliers and households than at the farm-level; and 3) farm-level net returns vary significantly depending on the conservation practices used, and the greater the change in farm-level net returns, the greater the net economic effect on the local food system in terms of employment, and valueded.

In Taiwan increasing importance has recently been attached to non-point source pollution(NPS), primarily because of the deteriorated water quality and eutrophication of reservoir watershed that it can result in non-point source pollution. This study aims to understand the non-point source pollution load resulting from a large rain storm event in the Mu-dan Reservoir watershed. Most of the upper catchment of the Mu-dan Reservoir watershed is used for agricultural activities. This study established a database for the Mu-dan Reservoir watershed by using IWMM (Integrated Watershed Management Model), delineated for sub-watershed, and investigate the serious NPS pollution in the Mu-dan Reservoir watershed. Mu-dan Creek watershed and Ru-Reng Creek watershed, two the major sub-watersheds of the Mu-dan Reservoir watershed. A Geographic Information System (GIS) that was established in the watershed to (monitor OR gather) geographic parameter data was used IWMM to simulate the impact of NPS pollution on river water quality in the Mu-dan Creek and Ru-Reng Creek watersheds in 2003 and 2006. The simulation results by IWMM were applied to examine the potential of NPS pollution management plans in the Mu-dan Reservoir watershed. The simulation results for the Mu-dan Reservoir watershed during 2003 were as follows: the total pollutant load of ammonia-nitrogen (NH3-N) nearly 65699.4 kg/year, and the total pollutant load of nitrate ¡Vnitrogen (NO3-N) nearly 91100.5 kg/year. Meanwhile, the results for 2006 were as follows: the total pollutant load of ammonia-nitrogen (NH3-N) nearly 48168.1 kg/year, and the total pollutant load of nitrate ¡Vnitrogen (NO3-N) nearly43962.7kg/year. The simulation results addressed remedial strategies adopted to reduce the impact of NPS pollution on water quality, apply natural treatment systems for stormwater runoff treatment, and apply best management practice to control NPS pollutants. Finally, this study hopes make progress towards effective management of watersheds. KEYWORDS: Integrated watershed management model; non-point source pollution; BMPs

No description available.

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.

The U.S. Army Corps of Engineers, Nashville District, maintains ten reservoirs in the Cumberland River Basin in Kentucky and Tennessee, and has been monitoring sediment chemistry in the reservoirs since 1994. The purpose of this study is to evaluate the sediment data collected from the reservoirs from 1994 to 2010 to determine if there are any spatial patterns of the trace elements: arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, and zinc. The results indicated that trace element levels were consistent with national baseline concentrations measured by the U.S. Geological Survey. Center Hill reservoir had the greatest number of trace element concentrations (all except cadmium) that were significantly higher when compared to all other reservoirs. The degree of urbanization in the reservoir basins was based on population density from the 2000 Census and the percentage of developed land using the 2006 national land cover dataset. Aquatic toxicity values were used as a measure of sediment quality. The reservoirs with the worst aquatic toxicity rankings were not the most urban, instead they were the reservoirs with the longest retention times. Therefore, it may be concluded that retention time has a larger effect on Cumberland River Basin sediment concentrations than the type of land use or the degree of urbanization. The results also indicate that it may be prudent to include an evaluation of quality based on aquatic toxicity when monitoring sediment quality, and that when reservoirs are the subject of sediment quality assessments, the consideration of the physical properties of the reservoir, especially the retention time, is essential for a comprehensive evaluation. This may also imply that sediment quality in reservoirs may effectively be regulated by water resource management techniques at the reservoirs that affect retention time.

The Upper North Bosque River (UNBR) watershed is under a Total Maximum Daily Load (TMDL) mandate to reduce Phosphorus (P) due to excess nutrients in the watershed. To address these problems, Texas A&M University researchers have developed a turfgrass sod Best Management Practice (BMP) to remove excess nutrients from impaired watersheds. Turfgrass harvest of manure fertilized sod removes a thin layer of topsoil with most of the manure applied P. Plot and field scale research has demonstrated the effectiveness of turfgrass to remove manure phosphorus (P). In order to assess the impact of the turfgrass BMP on a watershed scale, the Soil and Water Assessment Tool (SWAT) was used to predict water quality in the UNBR watershed. The SWAT model was modified to incorporate turfgrass harvest routines to predict manure and soil P export through turfgrass sod and soil during harvest. SWAT simulations of the BMP predicted stream load reductions of 20 to 36% for P loads in the UNBR depending on the implementation scenario, an average reduction of 31% for total N and 16.7% for sediment for all the scenarios, at the watershed outlet. The SWAT model also predicted up to 176 kg/ha P removed per sod harvest when fertilized with 100 kg manure P/ha, and 258 kg/ha of P removed per sod harvest when the manure P application rate was 200 kg/ha. In addition, depending on the implementation scenario, the turfgrass BMP could export between 262 and 784 metric tons of P out of the UNBR watershed every year. Manure fertilized turfgrass has the advantage of slow releasing nutrients from the composted dairy manure, so it would not require any additional P for life. This means reduced urban non-point source pollution and lower maintenance cost compared to regular sod. These modeling simulations complement the wealth of research that shows the effectiveness of the turfgrass BMP.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22785号 / 農博第2428号 / 新制||農||1081(附属図書館) / 学位論文||R2||N5305(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 藤原 正幸, 教授 村上 章, 教授 中村 公人 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

付記する学位プログラム名: グローバル生存学大学院連携プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20341号 / 工博第4278号 / 新制||工||1662(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 寶 馨, 教授 立川 康人, 准教授 佐山 敬洋 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Non-point source pollution caused by erosion from road construction poses hazardous environmental effects. Percolation and infiltration of nutrients into groundwater can also be detrimental to the surrounding environment. In addition, annual roadside maintenance budget exceeded $14 million in 2011 for Mississippi. Objectives of this research were to evaluate rapidly established short-statured species in an effort to prevent erosion, combat non-point source pollution, reduce mowing cost, and provide quick cover following propagation. Factors evaluated were rate of establishment, plant cover, and mowing requirement. MDOT’s standard seed mix was evaluated along with Pennington’s SlopeMaster product and different combinations of selected plant species. Visual and image analysis showed oilseed radish plants established the quickest and provided the most cover. All sod treatments provided instant cover while Pennington’s Slopemaster product, as well as mixes that contained bermudagrass or bahiagrass, provided sufficient cover, but not in a timely manner.

No description available.