• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 53
  • 10
  • 1
  • Tagged with
  • 64
  • 64
  • 41
  • 40
  • 40
  • 39
  • 39
  • 39
  • 38
  • 20
  • 20
  • 15
  • 12
  • 11
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Considering Climate Change Through Global Water Initiatives

Haverland, Arin C. January 2015 (has links)
Hundreds of international water institutions have been established over the last three decades in an attempt to address global water issues. Despite great efforts by these and other institutions, a significant percentage of the world's population still lacks access to clean water and sanitation facilities. Although billions of dollars have been spent on development, infrastructure and public health endeavors meant to tackle such issues, little research has been done to examine how these often influential organizations known as global water initiatives (GWIs) are addressing such urgent issues in the face of a rapidly changing climate. As water is central to the hydrological cycle, and affected by changes in climate, examining the role of GWIs in the use and translation of climate-change science may lead to better understanding of the mechanisms through which such organizations are linking climate change to their work in water management and governance. By examining 170 GWIs through two distinct phases of methodology, it was found that GWIs are addressing climate change issues through their work with water. Evidence presented in this research supports the claim that GWIs have adopted climate change as part of their overall operational frameworks and that their missions may be supported and ultimately achieved through the addition of climate-change science. While GWIs are shown to use climate-change science in setting objectives, and in decision making, it was also found that issues of cost, access, and utility remain as significant barriers. Findings presented in this study also suggest that intergovernmental and nongovernmental organizations, alongside professional societies dedicated to trades and disciplines related to water, are among the most important categories of GWIs, and as such, operate within a series of complex networks. This research also revealed that activities and outputs of GWIs enhance water management and governance, contribute to the world's knowledge base on water, and highlight the need to acknowledge GWIs as an important and prominent aspect of the global water dialogue.
2

Green School Guidelines & Application in Arid Regions

Gardner, Ambar 25 April 2015 (has links)
Sustainable Built Environments Senior Capstone Project / There is a worldwide movement towards sustainability. A stepping-stone towards a sustainability conscience population starts in the education of the younger generation. Focusing on improving education specifically in middle schools in arid regions regarding sustainability will shift and shape youths’ interests and lifestyles into an educated community. This sustainability conscience community will continue to make moral sustainable decisions in their future endeavors. The curriculum implemented will reduce the dropout rate because it is a hand-on curriculum that is interesting and enjoyable for kids. The focus of the curriculum is to rely on outdoor activities to create an outdoor learning environment. The curriculum is based on three different sections: 1) campus-wide adaptable strategies implemented by the students, 2) long term investments implemented by professionals, 3) and hands-on activities that will encourage students to go outdoors and experience real-life problems. To create this education system, the author will propose design guidelines and applications that will be used to improve middle schools particularly in arid regions to become “Green Schools”. This program will validate the sustainable strategies, projects, and efforts done at schools and will also market their school as a model to follow. This will explain what it takes to become a Green School in arid regions and how to achieve these standards.
3

How Do We Keep Conservation Alive When Kids Have Less and Less Contact with Nature?

Payan, Rafael January 2012 (has links)
An unsettling trend is gaining momentum - many Americans may be losing their interest in the `natural world'. According to research undertaken by Patricia Zaradic, an Environmental Leadership Program fellow in Bryn Mawr, and Oliver Pergams of the University of Illinois at Chicago, "nature just isn't as entertaining as it used to be." Studies of Americans' recreational habits show a nearly 25 percent per capita decline in camping, fishing, hunting and visits to state and national parks since the mid-1980s (Gambino 2008). Like "climate change," some suggest that the downward trend in outdoor recreation by Americans is a manifestation of fiction rather than fact. But the trend is unmistakable: A smaller percentage of people in the United States and elsewhere are participating in outdoor recreation (Smith 2008). Pergams and Zaradic show a trend in human behavior that ultimately may be far more foreboding for the environment than declining tropical forest cover or increasing greenhouse gas emissions - widespread declines in nature-based recreation (Kareiva 2008). The question that has yet to be answered is to what degree this trend will have in influencing our society's future and in how we will value - or devalue - our natural environment. Will future generations that grow up and live in a world estranged from the natural environment want to protect it? America's 200-year conservation tradition may be at risk. Two dominant factors influenced the environmental philosophies of notable historic American conservationists. One was their direct and repeated interaction with the natural world beginning at a very early age; the other was an environment-focused family tradition. These same factors influenced the environmental ethos of today's conservationists, land managers and environmental educators. It is impossible to determine if these factors will be of equal significance one hundred years from now. However, we can predict with reasonable certainty based on the recent historic record, motivators identified by current environmentalists, and the results of independent surveys of adolescent subjects reported in this study that, at least for now and for the foreseeable future, if implemented in combination with others variables, these will favorably influence the conservation ethic of our youngest citizens.
4

Woody plant proliferation in desert grasslands: perspectives from roots and ranchers

Woods, Steven Richard January 2014 (has links)
The widespread proliferation (or 'encroachment') of trees and shrubs in grasslands over the past 150 years is embedded in both natural and human systems. This dissertation addressed the following ecological and ethnoecological questions. Can seedling traits help us understand why so few woody species have encroached markedly into North American desert grasslands, and the conditions likely to promote their proliferation? What is the role of informal knowledge of the environment in efforts to manage woody plant abundance? Woody seedling survival often depends on rapid taproot elongation. In glasshouse experiments, initial water supply markedly affected taproot elongation in young seedlings. Response patterns may help explain recruitment patterns in Larrea tridentata, the principal evergreen woody encroacher in Sonoran and Chihuahuan Desert grasslands, and in Prosopis velutina and Prosopis glandulosa, the principal deciduous woody encroachers in Sonoran and Chihuahuan Desert grasslands, respectively. P. velutina and P. glandulosa showed greater sensitivity to water supply levels at the seedling stage than did the similar, related non-encroachers, Acacia greggii, Parkinsonia florida and Parkinsonia aculeata . This enabled the Prosopis species to overcome lower seed and seedling biomass to achieve similar taproot length to A. greggii and the Parkinsonia species. Consequently, population level advantages of lower seed mass, such as high seed numbers, may enhance encroachment potential in the Prosopis species without being negated by corresponding seedling survivorship disadvantages. I used semi-structured interviews to document informal rangeland monitoring by ranchers in southeast Arizona. Ranchers used qualitative methods to assess forage availability, rangeland trends and responses to woody plant suppression measures. Informal rangeland assessments informed ranchers' management decisions on sub-yearly, yearly and multi-year timescales. Informal monitoring appeared largely compatible with formal monitoring and natural science, and most ranchers integrated the two systems. Informal rangeland assessments can be valuable in planning woody plant suppression measures, particularly in light of the small number of formal long-term studies of brush suppression. Ecological studies may help predict places and periods of relatively rapid encroachment, perhaps enabling early or pre-emptive brush suppression measures. Thus, both seedling ecology and informal environmental knowledge are likely to be useful in managing woody plant populations in desert grasslands.
5

Unintended Consequences: A Study of Federal Policy, the Border Fence, and the Natural Environment

Hilliard, Josephine Antoinette January 2014 (has links)
Borders and border barriers can be breached and boundaries and political agendas can change. The Great Walls of China, Hadrian's Wall, and the Iron Curtain have lost their strategic value. Walls are contested presently in the Middle East. And the unpopulated DMZ in Korea, while still of strategic value, is being recognized for its biodiversity and resurgence of endangered flora and fauna. Presently, the United States is building a defensive wall along the U.S.-Mexico border in the name of national security and to stem the tide of drug and human trafficking. In the process it has waived numerous environmental laws thereby putting transboundary ecosystems in danger of irreparable harm. Why should there be interest? For the reason, as put forth by Mumme and Ibáñez, that while much attention has been paid to adverse environmental effects within the United States, "little attention has been given to the potentially complicated effects of the international boundary, water, and environmental agreements to which [the United States and Mexico] are party should Mexico choose to press its rights at the level of international law. . . . As international treaties and protocols, these agreements enjoy a legal standing that may supersede the authority of most domestic legislation." The implications are far reaching. Mexico has sent diplomatic notes to the U.S. embassy in Mexico and to the U.S. Department of State, and the Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT), Mexico's environment secretariat, has held informal talks with the Department of the Interior (DOI) and with the Secretary of Homeland Security--all apparently of no avail. Canada's notes have been similarly ignored by the Department of Homeland Security. What then for the U.S-Mexico border fence? Will it eventually become a relic of past political policy? Is the United States to ignore the lessons of the past and void its environmental treaties and agreements with Mexico? Should we not be concentrating on comprehensive immigration reform and the causes of drug abuse in the United States rather than a short-term solution to long-term problems?
6

DroughtView: Satellite-based Drought Monitoring and Assessment

Weiss, Jeremy, Crimmins, Michael 05 1900 (has links)
6 pp. / Remotely sensed data are valuable for monitoring, assessing, and managing impacts to arid and semi-arid lands caused by drought or other changes in the natural environment. With this in mind, we collaborated with scientists and technologists to redevelop DroughtView, a web-based decision-support tool that combines satellite-derived measures of surface greenness with additional geospatial data so that users can visualize and evaluate vegetation dynamics across space and over time. To date, users of DroughtView have been local drought impact groups, ranchers, federal and state land management staff, environmental scientists, and plant geographers. Potential new applications may include helping to track wildland fire danger. Here, we present the functionality of DroughtView, including new capabilities to report drought impacts and share map information, as well as the data behind it.
7

Growth, Equity, and Sustainability: A Case Study of the Impacts of Green Revolution Change in Ceará, Northeast Brazil

de Oliveira Mayorga, Fernando Daniel January 2016 (has links)
The objective of this dissertation is to understand the impacts of the Green Revolution on well-being, poverty and on the natural environment within a case study of Guaraciaba do Norte, a small município on a highland plateau surrounded by the semi-arid caatinga in Northeast Brazil. The Green Revolution technology was introduced in the early 1970's and has since transformed the município of Guaraciaba do Norte. Through the analysis of empirical data three different categories of stakeholders were identified and compared, the traditional rainfed producers located in the carrasco (semi-arid region) and zona húmida (humid zone of the plateau) and the Green Revolution producers called irrigators, located along the rivers. With respects to well-being, the research shows that the Green Revolution had a significant and positive affect on economic growth and development, reducing inequality and poverty levels in the município, as well as having significant multiplier effect on the non-agricultural sector, which is highly dependent on the vegetable production activates. Despite this, there are concerns of increased levels of vulnerability and its role in restricting access of new producers in adopting this technology. The abusive use of pesticides in the initial stages and improper disposal of packaging created environmental issues however, these have been resolved over time. Additionally, climate change effects have led to concerns related to the reduced water availability and consequently the future of agricultural activity in the region.
8

Land Use Predictors Affecting Land Disturbance in Exurban Arivaca, Arizona

Regan, John Joseph Jr. January 2011 (has links)
Exurbanization is occurring where large tracts of land are being sold to developers. Typically these are ranches that are then divided into 40-acre parcels and sold by developers, avoiding subdivision regulations requiring paved streets, utilities and other amenities. The result is an unplanned subdivision with no infrastructure, and tax revenues that cannot offset the cost of providing it. Interviews with professional planners suggested there may be independent variables capable of predicting the amount of human disturbance in an exurban area: parcel size, full cash value, tenure, distance to paved roads, site-built housing, mobile homes, and presence of biological or riparian areas. A total of 7,465 acres (3,022 ha) of parcel disturbance were digitized in exurban Arivaca, acreage values were converted to a binary dependent variable and used in logistic regression analysis to test independent variables' predictive value. Four were statistically significant: parcel size, full cash value, mobile homes and site-built housing. Landscape fragmentation was also tested using the presence of the variable scoring highest in probability - site-built housing. Zones of influence with a negative ecological influence surrounded the homes - up to 5,055 acres (2,046 ha) were impacted. Interviews with an exemplary sample of residents regarding their land use ethic found all had very strong opinions on how their properties should be treated as well as undesirable land uses such as overgrazing, over-use of groundwater for short-term economic gain and use of off-road vehicles. An explanation of the small sample size of both planners and residents is warranted. Planners were limited to those working in Pima County government who had professional experience with the study area of Arivaca and were familiar with its particular situation. The number of Arivaca residents interviewed was intended to discern an exemplary group's opinions based on how large a parcel they owned, the various sizes being a typical cross-section of acreage in the study area. What these findings illustrate is (1) the difficulty of predicting human-induced disturbance, (2) land fragmentation is more than the actual areas of physical disturbance and (3) some residents are aware of impacts related to their activities, mitigating damage wherever possible.
9

Social embeddedness of traditional irrigation systems in the Sonoran Desert: a Social Network Approach

Navarro Navarro, Luis Alan January 2012 (has links)
This research applied the social network approach to unveil the social structure underlying the members of two traditional irrigation systems (TISs) in Sonora. This research used two TIS case studies representing rural communities located in arid and semiarid lands in the Sonoran Desert region, in the northwestern part of Mexico. The irrigators represented a subset of rural villages where everyone knew everyone else. The theoretical framework in this study suggested that social embeddedness of the economic activities of TIS irrigators is an important factor supporting their local institutions. Irrigators who are socially embedded posses more social capital that help them in overcoming social dilemmas. Evidence of social embeddedness is theoretically incomplete when not related to a tangible dimension of the TIS's performance. This research also dealt with the difficulty of assessing the sustainability or successfulness of a TIS. The results showed that the irrigators sharing a rural village are entangled in a mesh of social ties developed in different social settings. The most salient variable was family; cooperative ties within the irrigation system tend to overlap more than the expected by chance with kinship relationships. Likewise, irrigators had a strong preference for peers geographically close or those within the same irrigation subsector. Finally, the qualitative part of the study did not reveal the presence of severe social dilemmas. Irrigators in each community have developed successful forms of local arrangements to overcome the provision and appropriation issues typical of common pool resources. Nevertheless, the qualitative analysis revealed that there are other socioeconomic variables undermining the sustainability of the systems, such as migration, water shortages and social capacity of the systems.
10

Malus Diversity in Wild and Agricultural Ecosystems

Routson, Kanin Josif January 2012 (has links)
Human-induced land degradation and climate change can reduce agricultural productivity and increase susceptibility to food shortages at local and global scales. Planting perennial crop species, such as fruit and nut crops, may be an intervention strategy because of their beneficial contributions to sustainable agriculture and human nutrition. Many perennial temperate fruit and nut species are however, particularly vulnerable to frost events, drought, insufficient chill hours, and disease and insect outbreaks. Modifying these species to yield harvests under a wider range of biotic and abiotic conditions may increase the value and long-term viability of perennials in agroecosystems. This dissertation examines adaptation and ecogeography in temperate perennial fruit crops, using apple (Malus sensu lato) as an example for case studies. The resilience of feral domestic apple trees in abandoned farmstead orchards throughout the southwestern U.S. indicates plasticity in adapting to local environmental conditions. Dendrochronology reveals these trees tend to persist where they have access to supplemental water, either as shallow groundwater or irrigation. While domestic apples are cultivated under a range of growing conditions, wild relatives of agricultural crops may further expand the cultivable range of the species. Crop wild relatives are species closely related to agricultural species, including progenitors that may contribute beneficial traits to crops. Sampling the genetic variation in crop wild relatives may benefit from ecological genetics and GIS theory to reveal genetic structure. The Pacific crabapple is an example of a wild apple relative that may contain genetic variation useful in apple breeding. Species distribution modeling of the Pacific crabapple identifies a narrow climatic window of suitable habitat along the northern Pacific coast, and genetic fingerprinting reveals a highly admixed genetic structure with little evidence of natural or cultural selection. While the moist coastal Pacific Northwest is not necessarily characteristic of many apple-growing regions, the species may have useful adaptations transferable to domestic apples. Genetic resources offer a promising source of raw material for adapting crops to future agricultural environments; their characterization, conservation, and use may offer important contributions to adaptation and use of perennial crops in agro-ecosystems.

Page generated in 0.0684 seconds