Quantifying future water resources availability and agricultural productivity in agro-urban river basins

Includes bibliographical references.2022 Fall.Climate change can have an adverse effect on agricultural productivity and water availability in semi-arid regions, as decreases in surface water availability can lead to groundwater depletion and resultant losses in crop yield due to reduced water for irrigation. Competition between urban and agricultural areas intensifies groundwater exploitation as surface water rights are sold to growing municipalities. These inter-relationships necessitate an integrated management approach for surface water, groundwater, and crop yield as a holistic system. This dissertation provides a novel integrated hydrologic modeling approach to quantify future water resources and agricultural productivity in agro-urban river basins, particularly in arid and semi-arid regions where surface water and groundwater are managed conjunctively to sustain urban areas and food production capacity. This is accomplished by i) developing an integrated hydrologic modeling code that accounts for groundwater and surface water processes and exchanges in large regional-scale managed river basins, and demonstrating its use and performance in the economically diverse South Platte River Basin (SPRB), a 72,000 km2 river basin located primarily in the state of Colorado, USA; ii) using the model to understand possible future impacts imposed by climate variation on water resources (surface water and groundwater) and agricultural productivity; and iii) quantifying the combination impacts of agriculture-to-urban water trading and climate change on groundwater resources within the basin. This dissertation presents an updated version of SWAT-MODFLOW that allows application to large agro-urban river basins in semi-arid regions. SWAT provides land surface hydrologic and crop yield modeling, whereas MODFLOW provides subsurface hydrologic modeling. Specific code changes include linkage between MODFLOW pumping cells and SWAT HRUs for groundwater irrigation and joint groundwater and surface water irrigation routines. This conjunctive use, basin-scale long-term water resources, and crop yield modeling tool can be used to assess future water and agricultural management for large river basins across the world. The updated modeling code is applied to the South Platte River Basin, with model results tested against streamflow, groundwater head, and crop yield throughout the basin. To assess the climate change impacts on water resources and agricultural productivity, the coupled SWAT-MODFLOW modeling code is forced with five different CMIP5 climate models downscaled by Multivariate Adaptive Constructed Analogs (MACA), each for two climate scenarios, RCP4.5, and RCP8.5, for 1980-2100. In all climate models and emission scenarios, an increase of 3 to 5 °C in annual average temperature is projected by the end of the 21st century, whereas variation in projected precipitation depends on topography and distance from the mountains. Based on the results of this study, the worst-case climate model in the basin is IPSL-CM5A-MR-8.5. Under this climate scenario, for a 1 °C increase in temperature and the 1.3% reduction in annual precipitation, the basin will experience an 8.5% decrease in stream discharge, 2-5% decline in groundwater storage, and 11% reduction in crop yield. In recent decades, there has been a growing realization that developing additional water supplies to address new demands is not feasible. Instead, managing existing water supplies through reallocations is necessary to tackle water scarcity and climate change. However, third-party effects associated to water transfers has limited the growing water market. This study also quantifies the combination impacts of agriculture-to-urban water trading (widely known as 'buy and dry') and climate change on groundwater availability in semi-arid river basins through the end of 21st century, as groundwater pumping increases to satisfy irrigation water lost to the urban sector. For this analysis, we use the hydrological modeling tool SWAT-MODFLOW, forced by projected water trading amounts and two downscaled GCM climate models, each for two emission scenarios, RCP4.5 and 8.5. According to the results of this study, agriculture-to-urban water trading imposes an additional basin-wide 2% reduction in groundwater storage, as compared to changes due to climate. However, groundwater storage changes for local subbasins can be up to 8% and 10% through the mid-century and end of the century, respectively

PERFORMANCE EVALUATION OF SINGLE-HOP PERIODIC SAFETY BEACONING FOR VEHICLE-TO-VEHICLE COMMUNICATION IN V ANET

Saving human lives on road has become the prime objective of Vehicular Ad hoc Network (VANET). In order to achieve safety, vehicles maintain neighborhood awareness with the help of safety messages. Providing an efficient safety messaging mechanism is a challenging task in V ANET, due to particular characteristics of VANET, i.e. high mobility, limited channel bandwidth, very short communication duration, and highly dynamic topology. In most of the safety messaging schemes proposed so far, Periodic Safety Beacons (PSBs) are generally considered dispensable in comparison with event-driven messages. However in reality, vehicle-to-vehicle (V2V) PSBs are used to collect critical information required by all the safety messaging schemes and cannot be dispensed. Thus, ensuring optimum QoS for V2V single-hop PSBs is essential for achieving acceptable level of safety. However, thorough performance evaluation ofV2V single-hop PSBs is yet to be carried out. This research comprehensively investigates V2V single-hop periodic safety beaconing in the light of tunable parameters i.e. Beacon Generation Interval (BGI), Safety Beacon Size (SBS), and Communication Range (CR) that govern their behavior. Results from exhaustive simulations show that adjusting tunable parameters solely or combined does not fully satisfY the strict QoS criterion required for safety applications. Overall, an acceptable level of end-to-end delay can be achieved by dynamically adjusting tunable parameters with BGI > 1 OOms, but lower BGI is not suitable with larger SBS. In dense traffic conditions strict PDR criterion of 99% is never achieved beyond lOOm target CR. An exclusive comparison between tunable parameters shows that solely adjusting BGI can attain relatively higher PDR than other tunable parameters while SBS remains the least effective parameter. It is also validated that dynamic adjustment of CR and BGI is necessary for optimal output in terms of PDR. Furthermore, optimal combinations of tunable parameters for different highway service levels with respect to safety application requirements are also presented

Learning material for constructing environmental understanding

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2003.Includes bibliographical references (p. 101-104).Environmental acknowledgement or awareness by itself does not necessarily implicate that people have understood the causes, effects and impact of environmental issues. Understanding and critically thinking about environmental problems is crucial and is not always addressed within the environmental education process. This deficiency is mainly due to the lack of adequate learning environments and suitable learning material. This study proposes an environmental education learning environment that was tested at the Fayerweather Street School in Cambridge, MA. During this study, motivated participants were fostered to engage in a personal project to address particular environmental issues, and were given the opportunity to design a methodology for conducting their own environmental projects. The learning environment included the use of technology-based learning material, such as electronic boards and environmental sensors, for people to interact with the chosen environment and produce data to support their arguments while addressing the environmental issue. As a result of the study, the participants produced two environmental projects. One of them was about measuring noise levels around the school, and it brought out the causes and effects of noise pollution in the context of the school. The other project was about measuring groundlevel ozone and comparing indoors and outdoors concentrations, this project exposed some characteristics of ground-level ozone particles and its formation process. The proposed learning environment provided an opportunity for people to understand environmental issues and critically address them within a meaningful context and it contributes to the enhancement of the process of environmental education.by Georgina Echaniz Pellicer.S.M

Advances in Molecular Simulation

Molecular simulations are commonly used in physics, chemistry, biology, material science, engineering, and even medicine. This book provides a wide range of molecular simulation methods and their applications in various fields. It reflects the power of molecular simulation as an effective research tool. We hope that the presented results can provide an impetus for further fruitful studies

Statistical physics approaches to large-scale socio-economic networks

Die statistische Physik erforschte im letzten Jahrzehnt eine Fülle von wissenschaftlichen Gebieten, was zu einem besseren quantitativen Verständnis von verschiedenen, aus vielen Elementen bestehenden Systemen, z.B. von sozialen Systemen, geführt hat. Eine empirische Quantifizierung von menschlichem Verhalten auf gesellschaftlichem Niveau hat sich allerdings bisher als sehr schwierig erwiesen, wegen Problemen bei der Gewinnung und Qualität von Daten. In dieser Doktorarbeit erstellen wir zum ersten mal einen umfangreichen über fünf Jahre gesammelten Datensatz, der praktisch alle Aktionen und Eigenschaften der 350.000 Teilnehmer einer gesamten menschlichen Gesellschaft aus einem selbstentwickelten Massive Multiplayer Online Game enthält. Wir beschreiben dieses aus stark wechselwirkenden Spielern bestehende soziale System in drei Ebenen. In einem ersten Schritt analysieren wir die Individuen und deren Verhalten im Verlauf der Zeit. Eine Skalen- und Fluktuationsanalyse von Aktions-Reaktions-Zeitreihen enthüllt Persistenz der möglichen Aktionen und qualitative Unterschiede zwischen "guten" und "schlechten" Spielern. Wir untersuchen danach den Diffusionsprozess der im Spieluniversum stattfindenden Bewegungen der Individuen. Wir finden Subdiffusivität und eine durch ein Potenzgesetz verteilte Präferenz zu kürzlich besuchten Orten zurückzukehren. Zweitens, auf der nächsthöheren Ebene, verwenden wir Netzwerktheorie um die topologische Struktur der Interaktionen zwischen Individuen zu quantifizieren. Wir konzentrieren uns auf sechs durch direkte Interaktionen definierte Netzwerke, drei davon positiv (Handel, Freundschaft, Kommunikation), drei negativ (Feindschaft, Attacke, Bestrafung). Diese Netzwerke weisen nichttriviale statistische Eigenschaften auf, z.B. skaleninvariante Topologie, und entwickeln sich in der Zeit, was uns erlaubt eine Reihe von Hypothesen über sozialdynamische Phänomene zu testen. Wir finden qualitative Unterschiede zwischen positiven und negativen Netzwerken in Evolution und Struktur. Schließlich untersuchen wir das Multiplex-Netzwerk der Spielergesellschaft, das sich aus den einzelnen Netzwerk-Schichten zusammensetzt. Wir quantifizieren Interaktionen zwischen verschiedenen Netzwerken und zeigen die nichttrivialen Organisationsprinzipien auf die auch in echten menschlichen Gesellschaften beobachtet wurden. Unsere Erkenntnisse liefern Belege für die Hypothese der strukturellen Balance, die eine Vermeidung von gewissen frustrierten Zuständen auf mikroskopischem Niveau postuliert. Mit diesem Aufbau demonstrieren wir die Möglichkeit der Gewinnung neuartiger wissenschaftlicher Erkenntnisse über die Natur von kollektivem menschlichen Verhalten in großangelegten sozialen Systemen.In the past decade a variety of fields has been explored by statistical physicists, leading to an increase of our quantitative understanding of various systems composed of many interacting elements, such as social systems. However, an empirical quantification of human behavior on a societal level has so far proved to be tremendously difficult due to problems in data availability, quality and ways of acquisition. In this doctoral thesis we compile for the first time a large-scale data set consisting of practically all actions and properties of 350,000 odd participants of an entire human society interacting in a self-developed Massive Multiplayer Online Game, over a period of five years. We describe this social system composed of strongly interacting players in the game in three consecutive levels. In a first step, we examine the individuals and their behavioral properties over time. A scaling and fluctuation analysis of action-reaction time-series reveals persistence of the possible actions and qualitative differences between "good" and "bad" players. We then study and model the diffusion process of human mobility occurring within the "game universe". We find subdiffusion and a power-law distributed preference to return to more recently visited locations. Second, on a higher level, we use network theory to quantify the topological structure of interactions between the individuals. We focus on six network types defined by direct interactions, three of them with a positive connotation (trade, friendship, communication), three with a negative one (enmity, attack, punishment). These networks exhibit non-trivial statistical properties, e.g. scale-free topology, and evolve over time, allowing to test a series of long-standing social-dynamics hypotheses. We find qualitative differences in evolution and topological structure between positive and negative tie networks. Finally, on a yet higher level, we consider the multiplex network of the player society, constituted by the coupling of the single network layers. We quantify interactions between different networks and detect the non-trivial organizational principles which lead to the observed structure of the system and which have been observed in real human societies as well. Our findings with the multiplex framework provide evidence for the half-century old hypothesis of structural balance, where certain frustrated states on a microscopic level tend to be avoided. Within this setup we demonstrate the feasibility for generating novel scientific insights on the nature of collective human behavior in large-scale social systems

Dagstuhl News January - December 2008

"Dagstuhl News" is a publication edited especially for the members of the Foundation "Informatikzentrum Schloss Dagstuhl" to thank them for their support. The News give a summary of the scientific work being done in Dagstuhl. Each Dagstuhl Seminar is presented by a small abstract describing the contents and scientific highlights of the seminar as well as the perspectives or challenges of the research topic

General Catalog 2007-2009

Contains course descriptions, University college calendar, and college administrationhttps://digitalcommons.usu.edu/universitycatalogs/1127/thumbnail.jp

General Catalog 2002-2004

Contains course descriptions, University college calendar, and college administrationhttps://digitalcommons.usu.edu/universitycatalogs/1123/thumbnail.jp