Matching Items (33)
Description
This study addresses the landscape connectivity pattern at two different scales. The county-level analysis aims to understand how urban ecosystem structure is likely to evolve in response to the proposed development plans in Maricopa County, Arizona. To identify the spatio-temporal land pattern change, six key landscape metrics were quantified in relative to the urban development scenarios based on the certainty of the proposed urban plans with different level of urban footprints. The effects of future development plans from municipalities on landscape connectivity were then analyzed in the scaled temporal and spatial frame to identify in which urban condition the connectivity value would most likely to decrease. The results demonstrated that tremendous amount of lands will be dedicated to future urbanization, and especially urban agricultural lands will be likely to be vulnerable. The metro-level analysis focuses on a group of species that represent urban desert landscape and have different degrees of fragmentation sensitivity and habitat type requirement. It hypothesizes that the urban habitat patch connectivity is impacted upon by urban density. Two underlying propositions were set: first, lower connectivity is predominant in areas with high urbanization cover; second, landscape connectivity will be impacted largely on the interfaces between urban, suburban, and rural areas. To test this, a GIS-based connectivity modeling was employed. The resultant change in connectivity values was examined for exploring the spatial relation to predefined spatial frames, such as urban, suburban, and rural zones of which boundaries were delineated by buffering method with two criteria of human population density and urban cover proportion. The study outcomes provide a practical guidance to minimize connectivity loss and degradation by informing planners with more optimal alternatives among various policy decisions and implementation. It also gives an inspiration for ecological landscape planning in urbanized or urbanizing regions which can ultimately leads urban landscape sustainability.
ContributorsPak, So-hyŏn (Author) / Cook, Edward (Thesis advisor) / Crewe, Katherine (Committee member) / Wu, Jianguo (Jingle) (Committee member) / Arizona State University (Publisher)
Created2011
Description
As a significant level of the reformation and transformation of our society has been provoked by environmental deterioration, ecological approaches in environmental design have drawn much attention from professionals as an alternative world view and also as a practical design approach. Particularly in landscape architecture, ecological understanding has been at the very core of the profession since its emergence and plays an important role in the decision making processes. While ecology supports the profession with an objective rationale, aesthetics plays another major role in providing various understandings about the aesthetic experience of people, which is rather subjective. However, the ways to seek the balance between them are still controversial. Furthermore, the conventional aesthetic value system of landscape appears to have limitations for guiding us to an appropriate appreciation, especially in dealing with newly emerging urban landscape patterns such as regeneration of post-industrial landscapes. Understanding these issues, there have been continuous attempts to describe the relation between ecology and aesthetics, suggesting that a new approach known as "ecological aesthetics," can bring us a new set of viewpoints seeking a reunion of nature and culture, and science and art. It asserts that "there is a type of beauty" in the landscape associated with its ecological health which people could aesthetically appreciate; and therefore, revealing the "hidden" beauty of nature in more visible ways should be the primary concern of today's ecological designers. This research mainly consists of extensive literature research and a case study on two landscape restructuring projects of post-industrial landscapes in Seoul, Korea. The literature research redefines the tasks of landscape architecture based on the idea of ecological aesthetics, and the case study seeks the potentials and limitations of current design projects. This research proposes a framework for landscape perception and reflects on the lessons that would be useful for better practice and research.
ContributorsMin, Byoung Wook (Author) / Cook, Edward (Thesis advisor) / Crewe, Katherine (Committee member) / Pijawka, David (Committee member) / Arizona State University (Publisher)
Created2011
Description
Haiti has witnessed high deforestation rates in recent decades, caused largely by the fuel needs of a growing population. The resulting soil loss is estimated to have contributed towards a decline in agricultural productivity of 0.5% -1.2% per year since 1997. Recent studies show the potential of biochar use through pyrolysis technology to increase crop yields and improve soil health. However, the appropriateness of this technology in the context of Haiti remains unexplored. The three objectives of this research were to identify agricultural- and fuel-use-related needs and gaps in rural Haitian communities; determine the appropriateness of biochar pyrolyzer technology, used to convert agricultural biomass into a carbon-rich charcoal; and develop an action-oriented plan for use by development organizations, communities, and governmental institutions to increase the likelihood of adoption. Data were collected using participatory rural appraisal techniques involving 30 individual interviews and three focus-group discussions in the villages of Cinquantin and La Boule in the La Coupe region of central Haiti. Topics discussed include agricultural practices and assets, fuel use and needs, technology use and adoption, and social management practices. The Sustainable Livelihoods framework was used to examine the assets of households and the livelihood strategies being employed. Individual and focus group interviews were analyzed to identify specific needs and gaps. E.M. Rogers' Diffusion of Innovations theory was used to develop potential strategies for the introduction of pyrolysis technology. Preliminary results indicate biochar pyrolysis has potential to address agricultural and fuel needs in rural Haiti. Probable early adopters of biochar technology include households that have adopted new agricultural techniques in the past, and those with livestock. Education about biochar, and a variety of pyrolysis technology options from which villagers may select, are important factors in successful adoption of biochar use. A grain mill as an example in one of the study villages provides a model of ownership and use of pyrolysis technology that may increase its likelihood of successful adoption. Additionally, women represent a group that may be well suited to control a new local biochar enterprise, potentially benefiting the community.
ContributorsDelaney, Michael Ryan (Author) / Aggarwal, Rimjhim (Thesis advisor) / Chhetri, Nalini (Committee member) / Henderson, Mark (Committee member) / Arizona State University (Publisher)
Created2011
Descriptionnone
ContributorsZamil, Ruaa (Author) / Parmentier, Mary J (Thesis advisor) / Chhetri, Nalini (Committee member) / Grossman, Gary (Committee member) / Arizona State University (Publisher)
Created2013
Description
Despite public demand for climate change mitigation and natural open space conservancy, existing political and design efforts are only beginning to address the declining efficacy of the biotic carbon pool (C-pool) to sequester carbon. Advances in understanding of biogeochemical processes have provided methods for estimating carbon embodied in natural open spaces and enhancing carbon sequestration efficacy. In this study, the benefits of carbon embodied in dryland open spaces are determined by estimating carbon flux and analyzing ecological, social, and economic benefits provided by sequestered carbon. Understanding the ecological processes and derived benefits of carbon exchange in dryland open spaces will provide insight into enhancing carbon sequestration efficacy. Open space carbon is estimated by calculating the amount of carbon sequestration (estimated in Mg C / ha / y) in dryland open space C-pools. Carbon sequestration in dryland open spaces can be summarized in five open space typologies: hydric, mesic, aridic, biomass for energy agriculture, and traditional agriculture. Hydric (wetland) systems receive a significant amount of moisture; mesic (riparian) systems receive a moderate amount of moisture; and aridic (dry) systems receive low amounts of moisture. Biomass for energy production (perennial biomass) and traditional agriculture (annual / traditional biomass) can be more effective carbon sinks if managed appropriately. Impacts of design interventions to the carbon capacity of dryland open space systems are calculated by estimating carbon exchange in existing open space (base case) compared to projections of carbon sequestered in a modified system (prototype design). A demonstration project at the Lower San Pedro River Watershed highlights the potential for enhancing carbon sequestration. The site-scale demonstration project takes into account a number of limiting factors and opportunities including: availability of water and ability to manipulate its course, existing and potential vegetation, soil types and use of carbon additives, and land-use (particularly agriculture). Specific design challenges to overcome included: restoring perennial water to the Lower San Pedro River, reestablishing hydric and mesic systems, linking fragmented vegetation, and establishing agricultural systems that provide economic opportunities and act as carbon sinks. The prototype design showed enhancing carbon sequestration efficacy by 128-133% is possible with conservative design interventions.
ContributorsHuck, Erick (Author) / Cook, Edward (Thesis advisor) / Green, Douglas (Committee member) / Brooks, Kenneth (Committee member) / Montemayor, Gabriel (Committee member) / Arizona State University (Publisher)
Created2012
Description
A niche group of non-traditional sports have grown in popularity over the course of most of the last century but especially in the last few decades. Adventure sports provide alternative forms of physical activity typically involving elements of nature, speed, adrenaline, and physical risk. These sports often take place in remote locations, require specialized equipment, and receive limited exposure to those that are not participants. There are many factors that contribute to limited participation within adventure sports but their popularity has continued to grow. Participants frequently devote much of their time, effort, and money showing a true passion for their sport. A case study on water skiers was performed to learn more about adventure sports and their participants. A detailed description of competitive water skiing is included because the competition format is not widely known. It was found that there are a number of reasons why people competitively water ski. The main ones are the unique sensations it offers, the water ski community, and the environment in which it takes place. It is a tough sport to become involved because of the costs, time commitments, access to lakes, and lack of knowledgeable skiers willing to mentor beginners. Although for different reasons, all respondents seemed to truly love the sport. People participate in adventure sports because of the unique aspects and opportunities involved with sports of this nature. The second portion is a coaching guide on all three events, driving, and judging including video examples of all but very high difficulty tricks. These tips and advice have been derived from fifteen years of experience with competitive water skiing. There is no single way to water ski but this is what one skier has found to help at each stage of improvement. It could not have been accomplished without the unimaginable amount of support received from family, coaches, and friends. It is always better to be watched by a coach but that is not always possible. This guide will give skiers a starting point for what to think about to help them figure out how to continue to improve in all three events. With the necessary time, resources, ambition, and circumstances; a small group of people who know nothing about water skiing could learn to become high performance competitors. It will be left with Sun Devil Water Ski Club to help future skiers who do not always have another skier to help teach them.
ContributorsMechler, Mason Charles (Author) / Chhetri, Nalini (Thesis director) / Yesenski, Tara (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05
Description
Now dry and broken, the Salt River once supplied a great legacy of Riparian vegetation through the Sonoran desert. This verdant landscape flourished from perennial flows of a river fed by high mountain snowmelt. However, multiple dams within those mountain canyons and channelization for the purpose of flood protection have nearly dried up the Salt. Through the process of design I examined the potential to repair, restore, and redevelop the river, choosing a site within the reach of the Salt River that currently includes an artificial retention area called Tempe Town Lake. Since 1999 a two mile portion of the river channel has contained the reservoir for the purpose of recreation and development within the city of Tempe. As I investigated the viability of restoring an urban desert river to a more natural riparian condition, I developed a master plan that merges ecological river restoration with sustainable urban development. Research into the vegetative communities historically occurring along the river's edge guided me to create a project based in ecological principles. Expanding the concrete channel to a wider river presence followed examples set by case studies and the historic character of the Salt River. A new braided low flow channel, allowed to meander with the natural currents of the river, is terraced upwards in a gentle slope that maintains current 500-year flow plains. The vegetation communities I propose to establish along the new terraced elevations are adapted from Charles H. Lowe's profile of a foothill canyon and archival research specific to this portion of the Salt River. As a way to support the reintroduction of Arizona's lost riparian plant communities, the master plan incorporates the use of greywater and A/C condensate collection from proposed developments along the river's edge. These new water systems would be substantial enough to sustain riparian vegetation creation and in addition, provide for ground water recharge. Additional developments continue the City of Tempe's goal to expand development along the river and adjacent to the downtown core. Providing for increased recreational opportunity in a river setting improves the quality of life in Tempe and sets the community apart from surrounding desert cities. By applying ecological and sustainable design and planning principles, the Salt River Diaries master plan repairs the river's flow, restores the riparian vegetation, and redevelops the edge between the city and river.
ContributorsBruckner, Coby Ryan (Author) / Fish Ewan, Rebecca (Thesis director) / Cook, Edward (Committee member) / Sykes, Astrid (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / The Design School (Contributor)
Created2014-05
Description
An investigation is undertaken of a prototype building-integrated solar photovoltaic-powered thermal storage system and air conditioning unit. The study verifies previous thermodynamic and economic conclusions and provides a more thorough analysis. A parameterized model was created for optimization of the system under various conditions. The model was used to evaluate energy and cost savings to determine viability of the system in several circumstances, such as a residence in Phoenix with typical cooling demand. The proposed design involves a modified chest freezer as a thermal storage tank with coils acting as the evaporator for the refrigeration cycle. Surrounding the coils, the tank contains small containers of water for high-density energy storage submerged in a low freezing-point solution of propylene glycol. The cooling power of excess photovoltaic and off-peak grid power that is generated by the air conditioning compressor is stored in the thermal storage tank by freezing the pure water. It is extracted by pumping the glycol across the ice containers and into an air handler to cool the building. Featured results of the modeling include the determination of an optimized system for a super-peak rate plan, grid-connected Phoenix house that has a 4-ton cooling load and requires a corresponding new air conditioner at 4.5 kW of power draw. Optimized for the highest payback over a ten year period, the system should consist of a thermal storage tank containing 454 liters (120 gallons) of water, a 3-ton rated air conditioning unit, requiring 2.7 kW, which is smaller than conventionally needed, and no solar photovoltaic array. The monthly summer savings would be $45.The upfront cost would be $5489, compared to a conventional system upfront cost of $5400, for a payback period of 0.33 years. Over ten years, this system will provide $2600 of savings. To optimize the system for the highest savings over a twenty year period, a thermal storage tank containing 272 liters (72 gallons) of water, a 40-m2 photovoltaic array with 15% efficiency, and a 3.5-ton, 3.1-kW rated air conditioning unit should be installed for an upfront cost of $19,900. This would provide monthly summer savings of $225 and 1062 kWh grid electricity, with a payback period of only 11 years and a total cost savings of $12,300 over twenty years. In comparison, a system with the same size photovoltaic array but without storage would result in a payback period of 16 years. Results are also determined for other cooling requirements and installation sizes, such that the viability of this type of system in different conditions can be discussed. The use of this model for determining the optimized system configuration given different constraints is also described.
ContributorsMagerman, Beth Francine (Author) / Phelan, Patrick (Thesis director) / Goodnick, Stephen (Committee member) / Chhetri, Nalini (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2013-05
Description
The City of Phoenix (Arizona, USA) developed a Tree and Shade Master Plan and a Cool Roofs initiative to ameliorate extreme heat during the summer months in their arid city. This study investigates the impact of the City's heat mitigation strategies on daytime microclimate for a pre-monsoon summer day under current climate conditions and two climate change scenarios. We assessed the cooling effect of trees and cool roofs in a Phoenix residential neighborhood using the microclimate model ENVI-met. First, using xeric landscaping as a base, we created eight tree planting scenarios (from 0% canopy cover to 30% canopy cover) for the neighborhood to characterize the relationship between canopy cover and daytime cooling benefit of trees. In a second set of simulations, we ran ENVI-met for nine combined tree planting and landscaping scenarios (mesic, oasis, and xeric) with regular roofs and cool roofs under current climate conditions and two climate change projections. For each of the 54 scenarios, we compared average neighborhood mid-afternoon air temperatures and assessed the benefits of each heat mitigation measure under current and projected climate conditions. Findings suggest that the relationship between percent canopy cover and air temperature reduction is linear, with 0.14 °C cooling per percent increase in tree cover for the neighborhood under investigation. An increase in tree canopy cover from the current 10% to a targeted 25% resulted in an average daytime cooling benefit of up to 2.0 °C in residential neighborhoods at the local scale. Cool roofs reduced neighborhood air temperatures by 0.3 °C when implemented on residential homes. The results from this city-specific mitigation project will inform messaging campaigns aimed at engaging the city decision makers, industry, and the public in the green building and urban forestry initiatives.
ContributorsMiddel, Ariane (Author) / Chhetri, Nalini (Author) / Quay, Raymond (Author)
Created2015
Description
Shade plays an important role in designing pedestrian-friendly outdoor spaces in hot desert cities. This study investigates the impact of photovoltaic canopy shade and tree shade on thermal comfort through meteorological observations and field surveys at a pedestrian mall on Arizona State University’s Tempe campus. During the course of 1 year, on selected clear calm days representative of each season, we conducted hourly meteorological transects from 7:00 a.m. to 6:00 p.m. and surveyed 1284 people about their thermal perception, comfort, and preferences. Shade lowered thermal sensation votes by approximately 1 point on a semantic differential 9-point scale, increasing thermal comfort in all seasons except winter. Shade type (tree or solar canopy) did not significantly impact perceived comfort, suggesting that artificial and natural shades are equally efficient in hot dry climates. Globe temperature explained 51 % of the variance in thermal sensation votes and was the only statistically significant meteorological predictor. Important non-meteorological factors included adaptation, thermal comfort vote, thermal preference, gender, season, and time of day. A regression of subjective thermal sensation on physiological equivalent temperature yielded a neutral temperature of 28.6 °C. The acceptable comfort range was 19.1 °C–38.1 °C with a preferred temperature of 20.8 °C. Respondents exposed to above neutral temperature felt more comfortable if they had been in air-conditioning 5 min prior to the survey, indicating a lagged response to outdoor conditions. Our study highlights the importance of active solar access management in hot urban areas to reduce thermal stress.
ContributorsMiddel, Ariane (Author) / Selover, Nancy (Author) / Hagen, Bjorn (Author) / Chhetri, Nalini (Author)
Created2016-05-18