ASU Scholarship Showcase

There are growing demands for detailed and accurate land cover maps in land system research and planning. Macro-scale land cover maps normally cannot satisfy the studies that require detailed land cover maps at micro scales. In the meantime, applying conventional pixel-based classification methods in classifying high-resolution aerial imagery is ineffective to develop high accuracy land-cover maps, especially in spectrally heterogeneous and complicated urban areas. Here we present an object-based approach that identifies land-cover types from 1-meter resolution aerial orthophotography and a 5-foot DEM. Our study area is Tippecanoe County in the State of Indiana, USA, which covers about a 1300 km[superscript 2] land area. We used a countywide aerial photo mosaic and normalized digital elevation model as input datasets in this study. We utilized simple algorithms to minimize computation time while maintaining relatively high accuracy in land cover mapping at a county scale. The aerial photograph was pre-processed using principal component transformation to reduce its spectral dimensionality. Vegetation and non-vegetation were separated via masks determined by the Normalized Difference Vegetation Index. A combination of segmentation algorithms with lower calculation intensity was used to generate image objects that fulfill the characteristics selection requirements. A hierarchical image object network was formed based on the segmentation results and used to assist the image object delineation at different spatial scales. Finally, expert knowledge regarding spectral, contextual, and geometrical aspects was employed in image object identification. The resultant land cover map developed with this object-based image analysis has more information classes and higher accuracy than that derived with pixel-based classification methods.

Cities around the world are facing an ever-increasing variety of challenges that seem to make more sustainable urban futures elusive. Many of these challenges are being driven by, and exacerbated by, increases in urban populations and climate change. Novel solutions are needed today if our cities are to have any hope of more sustainable and resilient futures. Because most of the environmental impacts of any project are manifest at the point of design, we posit that this is where a real difference in urban development can be made. To this end, we present a transformative model that merges urban design and ecology into an inclusive, creative, knowledge-to-action process. This design-ecology nexus—an ecology for cities—will redefine both the process and its products. In this paper we: (1) summarize the relationships among design, infrastructure, and urban development, emphasizing the importance of joining the three to achieve urban climate resilience and enhance sustainability; (2) discuss how urban ecology can move from an ecology of cities to an ecology for cities based on a knowledge-to-action agenda; (3) detail our model for a transformational urban design-ecology nexus, and; (4) demonstrate the efficacy of our model with several case studies.

As part of an international collaboration to compare large-scale commons, we used the Social-Ecological Systems Meta-Analysis Database (SESMAD) to systematically map out attributes of and changes in the Great Barrier Reef Marine Park (GBRMP) in Australia. We focus on eight design principles from common-pool resource (CPR) theory and other key social-ecological systems governance variables, and explore to what extent they help explain the social and ecological outcomes of park management through time. Our analysis showed that commercial fisheries management and the re-zoning of the GBRMP in 2004 led to improvements in ecological condition of the reef, particularly fisheries. These boundary and rights changes were supported by effective monitoring, sanctioning and conflict resolution. Moderate biophysical connectivity was also important for improved outcomes. However, our analysis also highlighted that continued challenges to improved ecological health in terms of coral cover and biodiversity can be explained by fuzzy boundaries between land and sea, and the significance of external drivers to even large-scale social-ecological systems (SES). While ecological and institutional fit in the marine SES was high, this was not the case when considering the coastal SES. Nested governance arrangements become even more important at this larger scale. To our knowledge, our paper provides the first analysis linking the re-zoning of the GBRMP to CPR and SES theory. We discuss important challenges to coding large-scale systems for meta-analysis.

Most studies on the response of socioeconomic systems to a sudden shift focus on long-term equilibria or end points. Such narrow focus forgoes many valuable insights. Here we examine the transient dynamics of regime shift on a divided population, exemplified by societies divided ideologically, politically, economically, or technologically. Replicator dynamics is used to investigate the complex transient dynamics of the population response. Though simple, our modeling approach exhibits a surprisingly rich and diverse array of dynamics. Our results highlight the critical roles played by diversity in strategies and the magnitude of the shift. Importantly, it allows for a variety of strategies to arise organically as an integral part of the transient dynamics-as opposed to an independent process-of population response to a regime shift, providing a link between the population's past and future diversity patterns. Several combinations of different populations' strategy distributions and shifts were systematically investigated. Such rich dynamics highlight the challenges of anticipating the response of a divided population to a change. The findings in this paper can potentially improve our understanding of a wide range of socio-ecological and technological transitions.

Urbanization continues to be a transformative process globally, affecting ecosystem integrity and the health and well being of people around the world. Although cities tend to be centers for both the production and consumption of goods and services that degrade natural environments, there is also evidence that urban ecosystems can play a positive role in sustainability efforts. Despite the fact that most of the urbanization is now occurring in the developing countries of the Global South, much of what we know about urban ecosystems has been developed from studying cities in the United States and across Europe. We propose a conceptual framework to broaden the development of urban ecological research and its application to sustainability. Our framework describes four key contemporary urban features that should be accounted for in any attempt to build a unified theory of cities that contributes to urban sustainability efforts. We evaluated a range of examples from cities around the world, highlighting how urban areas are complex, connected, diffuse and diverse and what these interconnected features mean for the study of urban ecosystems and sustainability.

This article identifies equity outcomes associated with three biofuel systems in Brazil, Ethiopia and Guatemala. Acknowledging that winners and losers are socially and politically generated, the article identifies some of the factors behind the distribution of winners and losers along different stages of three sugarcane-ethanol supply chains. Analysing the outcomes for equity within each case study reveals an uneven distribution that we argue is related to the procedure and structure of the given sugarcane-ethanol system, and the recognition of the impacts on different actors within those structures. Increasing equity in sugarcane-ethanol systems will require greater openness in decision making processes, in order that multiple voices are taken into account in the promotion, production and consumption of biofuels – particularly those of smaller and less powerful actors.

The purpose of applying social-ecological resilience thinking to food systems is twofold: First, to define those factors that help achieve a state in which food security for all and at all scales is possible. Second, to provide insights into how to maintain the system in this desirable regime. However, the resilience of food systems is distinct from the broader conceptualizations of resilience in social-ecological systems because of the fundamentally normative nature of food systems: humans need food to survive, and thus system stability is typically a primary policy objective for food system management. With that being said, society also needs food systems that can intensify sustainably i.e., feed everybody equitably, provide livelihoods and avoid environmental degradation while responding flexibly to shocks and uncertainty. Today’s failure in meeting food security objectives can be interpreted as the lack of current governance arrangements to consider the full and differential dimensions of food system functions – economic, ecological and social – at appropriate scales: in other words, the multifunctionality of food.

We focus on functional and response diversity as two key attributes of resilient, multifunctional food systems; respectively, the number of different functional groups and the diversity of types of responses to disturbances within a functional group. Achieving food security will require functional redundancy and enhanced response diversity, creating multiple avenues to fulfill all food system objectives. We use the 2013-15 drought in California to unpack the potential differences between managing for a single function – economic profit – and multiple functions. Our analysis emphasizes how the evolution of the Californian food system has reduced functional and response diversity and created vulnerabilities. Managing for the resilience of food systems will require a shift in priorities from profit maximization to the management for all functions that create full food security at multiple scales.