Master of Arts / Department of Geography / John A. Harrington Jr / Environmental degradation is a major concern in agricultural landscapes. Innovative tools and methods will be necessary to identify and deal with the ongoing environmental impacts of past and present agricultural practices. The use of scenarios in environmental modeling is one way to address these concerns. Recently a group of researchers devised a framework for creating future land cover scenarios for two physiographic regions in Iowa. Based on that work, a suite of scenarios were created for Antelope Creek watershed in the Northern Flint Hills of Kansas. The Antelope Creek scenarios represent conditions pre Euro-American settlement, present day, increased intensification of agricultural production, enhancement of water quality, and enhancement of biodiversity. These scenarios were then modeled using the Soil and Water Assessment Tool (SWAT). Additional model runs were completed to compare SSURGO and STATSGO soil datasets. Results indicated that reductions in discharge, total suspended sediment and various nitrogen and phosphorus loads could be achieved by implementing modest changes to agricultural management practices. Results also indicated that a higher detail soil dataset such as SSURGO lead to slightly higher loads than with STATSGO data.

Master of Science / Department of Civil Engineering / David R. Steward / The Ogallala Aquifer is a supply of water for several municipalities in western Kansas, as well as an irrigation source for local farmers. Since the 1950’s, when the aquifer started to be pumped for irrigation, the region has seen steady declines of the groundwater table. These declines have reduced stream flow in the Arkansas and Cimarrron Rivers, and caused a redistribution of riparian phreatophytes. This thesis studies this redistribution of phreatophytes, and develops statistical relationships relating a phreatophyte’s location to depth to groundwater, increase in depth to groundwater, distance from a stream or river, and hydrologic soil group. Remote sensing was used to determine tree locations on predevelopment and post-development aerial photography. These locations were mapped using ArcGIS, and ArcAEM was used to model groundwater flow in six riparian regions taking root uptake into account. It was found that once the depth to groundwater becomes greater than about 3 m, tree population will decrease as depth to water increases. Trees were located within 700 m of the river. Areas with a dense tree population (>10% tree cover) occurred where the average depth to water ranged from 0.24-1.4 m. Areas with moderate tree density (5-10% tree cover) corresponded to an average depth to water ranging from 2.1-19 m. Areas with a low tree density (<5% tree cover) corresponded to an average depth to water ranging from 11-28 m. It was found that phreatophytes have a high likelihood of growing on hydrologic soil group A and a low likelihood of growing on hydrologic soil group B. The number of trees located on hydrologic soil group D was what would be statistically expected if tree location were independent of soil type. It was also found that tree locations could be used as an indicator of good hydraulic connectivity between surface water and groundwater. This information can be used to help guide future installation of monitoring networks and expand research projects from central Kansas to western Kansas.

Master of Science / Department of Biological & Agricultural Engineering / Stacy L. Hutchinson / Soil erosion is a serious problem resulting in degradation of soil systems and nonpoint source (NPS) pollution of water resources. Concentrated overland flow is the primary transport mechanism for many NPS pollutants including soil, and locating areas where sheet flow transitions into concentrated flow is useful for assessing the potential for soil erosion. The ability to predict areas where overland flow transitions to concentrated flow and soil erosion potential is high assists land managers in implementing best management practices (BMPs) to reduce soil erosion and NPS. An erosion model, called the nLS model, was developed to identify transitional overland flow regions. The model is based on the kinematic wave overland flow theory and uses Manning’s n values, flow length, and slope as inputs to determine where overland flow transitions to sheet flow and soil erosion potential increases. Currently, the model has only been tested and validated for watersheds within Kansas. In order to assess model uncertainties and evaluate the model’s applicability to other regions, a sensitivity analysis on key input parameters was conducted. To assess model operations, several sensitivity analyses were performed on model inputs, including digital elevation models (DEMs) and landuse/landcover data (LULC). The impact of slope was assessed using two methods. First, by modifying the DEMs in a stepwise fashion from flatter to steeper terrains, and second, by modifying the elevation of each DEM cell based on the associated elevation error. To assess difficulties that might arise from the parameterization of surface roughness, LULC classes were assigned Manning’s n values within the suggested range using a Monte Carlo simulation. In addition, the critical threshold value used for locating erosion potential sites was modified, and alternative model calculations were used to assess the potential for improving model accuracy. Finally, the model was run using data from multiple sites, including two study areas in Hawaii and two in Kansas. The outputs for each site were analyzed in an attempt to identify any trends caused by site characteristics. Results from this study showed that the nLS model was sensitive to all of the inputs. Modifying the Manning’s roughness coefficient significantly altered the final nLS values and shifted the critical threshold points, especially in areas of the upper watershed. Changes in the slope value modified the nLS model outputs in a predictable manner, but there was some variability, especially in areas with lower slope values. In addition, discrepancies in the DEM, which may be present due to measurement or processing error, were shown to significantly alter the flow paths of a watershed. These findings suggest that accurate roughness coefficients and LULC data are especially important for regions with a steeper topography, and accurate elevation data is important for regions with lower slope values. The results also suggest that the threshold value for the model plays a vital role in locating potential soil erosion sites, and adjustments to this value could possibly be used as a method for calibrating the nLS model. Finally, the alternative model calculations used in this study did not significantly improve the accuracy of the nLS model, so the existing model is sufficient for obtaining accurate nLS estimates. The information gained from this study can improve the assessment of soil erosion processes due to concentrated overland flow. By successfully implementing a land management program that makes use of the nLS models, it should be possible to improve BMP placement and design, helping to improve water and soil quality.

La phytoextraction représente une solution environnementale prometteuse face au problème de contamination des sols en éléments traces (É.T). La présente étude s’intéresse aux différences intra et interspécifiques (S. purpurea, S. dasyclados, S. miyabeana) de trois cultivars de saule lorsqu’ils sont utilisés pour la phytoextration de six É.T. (As, Cd, Cu, Ni, Pb et Zn). Les objectifs sont (i) décrire les variations intrapécifiques du cultivar FISH CREEK (S. purpurea) lorsqu’il est utilisé pour la phytoextraction sur deux sites d’étude; et (ii) décrire les variations intra et interspécifiques des cultivars FISH CREEK (S. purpurea), SV1 (S. dasyclados) et SX67 (S. miyabeana) lorsqu’ils sont utilisés pour la phytoextraction d’un site d’étude. Les indicateurs de variations intra et interspécifiques sélectionnés sont les suivants : la biomasse totale, les concentrations en É.T. extraits et les facteurs de translocation (x ̅ pondérée des conc. É.T. dans les parties aériennes / conc. É.T. dans les racines). La contribution des propriétés du sol (degré de contamination, caractéristiques physicochimiques) à la phytoextraction a été évaluée. Les cultivars ont présenté des variations interspécifiques significatives. Cependant, les variations intraspécifiques sur un site d’étude étaient parfois plus importantes que celles mesurées entre les trois différents cultivars. L’amplitude des variations intraspécifiques que présentent le cultivar FISH CREEK sur deux sites d’étude est attribuée à l’influence du pH, de la minéralogie et au contenu en matière organique, lesquelles diffèrent entre les deux sites. Il a aussi été démontré que la phytoextraction des É.T. n’était pas systématiquement corrélée de façon positive avec le degré de contamination. Cela suggère que les concentrations en É.T. mesurées dans le sol ne peuvent pas expliquer à elles seules la variation des concentrations mesurées dans les tissus. L’implication des mécanismes de rétention dans le sol semblent être davantage responsable des variations observées. La compartimentation des É.T. suggère que le saule est efficace pour l’extraction du Cd et du Zn et qu’il est efficace pour la phytostabilisation de l’As, du Cu, du Ni, et du Pb. En ce qui concerne les quantités extraites, le cultivar FISH CREEK semble le plus performant dans la présente étude. / Phytoextraction is a promising solution to the environmental problem of soil contamination by trace elements (TE). This study focuses on intra and interspecific differences (S. purpurea, S. dasyclados, S. miyabeana) of three willow cultivars used for phytoextration of six TE (As, Cd, Cu, Ni, Pb and Zn). The objectives are (i) describe the interspecific variations of FISH CREEK cultivar (S. purpurea) used for phytoextraction on two study sites; and (ii) describe intra and interspecific variations of FISH CREEK (S. purpurea) SV1 (S. dasyclados) and SX67 (S. miyabeana) cultivars used for phytoextraction of a study site. The selected indicators of intra and interspecific variations are : total biomass, TE concentrations extracted and translocation factors (x ̅ weighted TE conc. in aerial parts / conc. TE in the roots). The contribution of soil properties (contamination level, physicochemical characteristics) to phytoextraction was evaluated. The cultivars showed significant interspecific variations. However, intraspecific variations were sometimes more important than variations measured between the three different cultivars grown on one study site. The magnitude of intraspecific variations of FISH CREEK cultivar grown on two study sites is attributed to the influence of pH, mineralogy and organic matter content, which differ between the two sites. It was also shown that the phytoextraction of TE was not consistently correlated positively with the contamination level. This suggests that the TE concentrations measured in soil can not by themselves explain the variation in the measured tissue concentrations. The involvement of retention mechanisms in soil appear to be more responsible for the observed variation. ET compartmentalization suggests that the willow is effective for Cd and Zn extraction and is effective for As, Cu, Ni, and Pb phytostabilisation. Regarding the amount extracted, cultivar FISH CREEK seems the most effective cultivar in this study.

褚涓. / "2010年9月". / "2010 nian 9 yue". / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 99-106). / Abstract in Chinese and English. / Chu Juan. / 論文摘要 --- p.i / Abstract --- p.ii / Chapter 第一章 --- 導論 --- p.1 / Chapter 第一節 --- 研究背景與研究問題 --- p.1 / Chapter 第二節 --- 理論文獻綜述 --- p.4 / “碎片化的權威主義´ح與“多元化´ح --- p.5 / 中國環保NGO的政治闡釋 --- p.11 / Chapter 第三節 --- 研究設計 --- p.16 / 研究對象 --- p.16 / 研究意義 --- p.17 / 資料收集 --- p.20 / 文章結構 --- p.20 / Chapter 第二章 --- 水壩政治的制度環境變遷 --- p.21 / Chapter 第一節 --- 水電體制改革：行動者與利益 --- p.23 / 水電管理與投資體制改革 --- p.23 / 水電的規劃與決策 --- p.26 / Chapter 第二節 --- 官僚政治：環保總局分享決策權 --- p.29 / 環保總局的“升遷´ح之路 --- p.29 / 環評制衡水電開發 --- p.30 / Chapter 第三節 --- 公民社會政治：環保NGO結緣江河開發 --- p.33 / 都江堰“保衛戰´ح --- p.34 / 漫灣電站社會影響評估 --- p.36 / Chapter 第三章 --- “保留一條原始生態江´ؤ´ؤ怒江！ ´ح --- p.38 / Chapter 第一節 --- 怒江水電開發政策議題的開端 --- p.38 / 怒江水電項目的由來 --- p.38 / 環保總局發力 --- p.40 / Chapter 第二節 --- 環保NGO的初期動員 --- p.44 / 掀起媒體“風暴´ح --- p.44 / 遊說官員 --- p.47 / 尋求國際社會的支援 --- p.49 / NGO之間的聯盟 --- p.S1 / 深入怒江考察和調研 --- p.52 / 通過兩會提案保護怒江 --- p.54 / Chapter 第三節 --- 總理批示：“慎重研究、科學決策´ح --- p.55 / 政府内部的角力 --- p.55 / 爭論聲中叫停 --- p.57 / Chapter 第四節 --- 社區行動與政府的反應 --- p.59 / 綠色流域走進社區 --- p.59 / 遭到打壓 --- p.62 / Chapter 第四章 --- 新一輪的挑戰與動員 --- p.65 / Chapter 第一節 --- 轉折：總理再次批示 --- p.65 / “傳媒戰´ح受挫與院士考察團訪問怒江 --- p.65 / 地方政府遊說中央 --- p.67 / Chapter 第二節 --- 環保NGO的第二輪動員 --- p.69 / 呼吁知情权与参与权 --- p.69 / 啟動法律工具 --- p.71 / Chapter 第三節 --- 陷入膠著 --- p.72 / 官方的表態 --- p.72 / 環保NGO的後續倡導 --- p.75 / Chapter 第四節 --- 虎跳峽、小南海電站再掀波瀾 --- p.77 / Chapter 第五章 --- 結論：決策開放化的解讀 --- p.80 / 政府的“碎片化´ح與“權威´ح --- p.82 / 利益代表：有序的政治參與官僚包辦 --- p.85 / 公眾參與的“陷阱´ح --- p.92 / 參考文獻 --- p.99 / 附件：訪談對象 --- p.107

As a result of rapid product development, the product life cycle has become shorter, and thus the amount of waste from discarded industrial products has risen dramatically. An awareness of the world???s environmental problems has stimulated researchers to explore the opportunities to reuse, recycle and remanufacture end-of-life products. Disassembly is a systematic approach to separating products into components or subassemblies in order to facilitate recovery of components or materials. However, the full disassembly of a product tends to be unproductive due to technical and cost constraints and product conditions after usage. Therefore, selective disassembly has been introduced as a more practical approach, where only a limited number of disassembly paths that lead to selected parts with recovering potential are considered. This research focuses on the development of a selective disassembly methodology by reversing an assembly sequencing approach. The methodology uses a step-by-step approach to generate a disassembly sequence diagram. This involves listing all the parts within the product, generating a liaison diagram to illustrate part relationships and then establishing precedence rules describing prerequisite actions for each liaison. This is followed by segregating disassembly paths that lead to the removal of selected parts or subassemblies. Then a winnowing process is applied to these paths to eliminate invalid disassembly states and transitions. The last step is to select the optimal disassembly path by using the time requirement as the main selection criterion. In order to shorten the time for carrying out the sequencing process, a javabased program that is capable of performing the first three steps has been created. The program requires three basic inputs in forms of precedence rules, and user-required part (s) and disassembly rules, prescribing which liaison (s) should be done subsequent to a particular liaison. The viability of the methodology and the program is proved through seven case studies conducted on a fishing reel, a single-hole punch, a kettle, an entire washing machine and three washing machine subassemblies. The application of the program allows the users to determine an optimal disassembly sequence in a very short time and with only basic product information as the input.

University of Macau / Faculty of Science and Technology / Department of Civil and Environmental Engineering

<p>Large-scale coherent structures are systematically investigated in terms of their geometric attributes, importance toward describing turbulent exchange of energy, momentum and mass as well as their relationship to landscape features in the context of land-atmosphere interaction. In the first chapter, we present the motivation of this work as well as a background review of large-scale coherent structures in land-atmosphere interaction. In the second chapter, the methodology of large-eddy simulation (LES) and the proper orthogonal decomposition (POD) is introduced. LES was used to serve as a virtual laboratory to simulate typical scenarios in land-atmosphere interaction and the POD was used as the major technique to educe the coherent structures from turbulent flows in land-atmosphere interaction. In the third chapter, we justify the use of the LES to simulate the realistic coherent structures in the atmospheric boundary layer (ABL) by comparing results obtained from LES of the ABL and direct numerical simulation (DNS) of channel flow. In the fourth chapter, we investigate the effects of a wide range of vegetation density on the coherent structures within the air space within and just above the canopy (the so-called canopy sublayer, CSL). The fifth chapter presents an analysis of the coherent structures across a periodic forest-clearing-forest transition in the steamwise direction. The sixth chapter focuses on the role of coherent structures in explaining scalar dissimilarity in the CSL. The seventh chapter summarizes this dissertation and provides suggestions for future study.</p> / Dissertation

published_or_final_version / abstract / toc / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

Reused, recycled and regional product criteria within the LEED Green Building rating system are not based on comprehensive environmental assessments and do not ensure a measurable and consistent reduction of environmental burdens. A life cycle assessment (LCA) was conducted for the LEED-certified Medical Sciences Building at the University of Victoria to illustrate how LCA can be used to improve these criteria. It was found that a lack of public LCA data for building products, insufficient reporting transparency and inconsistent data collection methodologies prevent a full incorporation of LCA into LEED. At present, LCA data can be used to determine what building products are generally associated with the highest environmental burdens per unit cost and thus require separate LEED criteria. Provided its deficiencies are rectified in the future, LCA can be fully incorporated into LEED to design environmental burden-based criteria that ensure a measurable and consistent reduction of environmental burdens.