In spite of decades of related research, stream channel initiation is still not well understood. Current theories of channel initiation are grounded in research conducted by Montgomery and Dietrich, largely in the transport limited, temperate, humid climate of the Pacific Northwest, USA. This field data driven work concluded that the drainage area required for channel initiation is directly correlated to the slope of the contributing area. However, there are a host of related variables that have yet to be examined in the field. This study revisits the slope-area relationship focusing on ephemeral overland flow in headwaters of both the Pacific Northwest and an environmentally contrasting island in Greece. By seeking greater understanding of the variables, such as soil properties, vegetation type, and lithology that may influence channel initiation, the study sought to find an equation for remote determination of where ephemeral flow concentrates. However, results indicated that a universal equation does not exist. Rather, the location of ephemeral flow concentration is linked to landscape type, transport versus weathering limited slopes, and corresponding overland flow type. As a result, there is potential for regional models to be developed. Two such models were found as part of this study. One indicates that in a weathering limited environment, Hortonian overland flow is the dominant ephemeral flow type and the driving force behind where it concentrates on the landscape. The other demonstrates that in a transport limited environment, ephemeral flow concentration is due saturated overland flow, with the key to location of concentration being the point of return flow.

Headwater stream systems are important components of the overall hydrologic system. Forestry best management practices (BMP) are effective at minimizing non point source pollution from forest harvesting activities. Streamside management zones (SMZ) are one BMP used to protect surface water quality by maintaining shade near streams, filtering runoff, and minimizing soil disturbance near streams. An evaluation of BMP effectiveness on the watershed scale was conducted at the University of Kentucky’s Robinson Forest. Six watersheds were harvested using a two-age deferment harvest with one of three SMZ configurations applied to each watershed. Two unharvested watersheds served as controls. Treatment 1 was based on the current Kentucky Forest Practice Guidelines for Water Quality Management and included a 16.8 m SMZ with 50% canopy retention for perennial streams, a 7.6 m SMZ with no canopy retention for intermittent streams, and no SMZ or canopy retention for ephemeral streams with unimproved crossings. Treatment 2 also included a 16.8 m perennial SMZ but increased canopy retention to 100%, as well as a 7.6 m intermittent SMZ with 25% canopy retention, and retention of channel bank trees and use of improved crossings for ephemeral streams. Treatment 3 required a 33.5 m perennial SMZ with 100% canopy retention, a 16.8 intermittent SMZ with 25% canopy retention, and a 7.6 m ephemeral SMZ with retention of channel bank trees and use of improved crossings. Total suspended solids (TSS) concentration and turbidity was measured in storm samples in perennial and ephemeral streams, and in non-storm samples in perennial and intermittent streams. Nitrate-N, ammonium-N, and dissolved oxygen concentrations were also measured in non-storm samples in perennial and intermittent streams. Temperature and water level were recorded every 15 minutes for the duration of the study. Results showed that treatment 3 was able to maintain TSS concentrations and turbidity levels similar to those measured in unharvested control watersheds. Increases in nitrate-N and mean daily temperature were measured for all treatments. Ammonium-N and dissolved oxygen concentrations were not different from unharvested control watersheds for any treatment. Storm hydrograph separation did not result in consistent changes post-harvest for any treatment.

Morphologic change of ephemeral stream cross-sections is a natural component of fluvial geomorphology but disruptions to natural erosion and deposition by anthropogenic disturbances has the potential for cascading impacts down the channel corridor. The proximal impact of a natural gas pipeline construction on ephemeral stream cross-section geometry in southern Arizona was evaluated from July 2014 (pre-construction) to July 2016 (two years post construction). Cross-sections at three locations (upstream the pipeline Right-Of-Way (ROW)), through the middle of the ROW, and downstream of the ROW) were measured using Light Detection And Ranging (LIDAR) and field methods for 16 ephemeral streams. Results of both the LIDAR and field measurements indicated insignificant difference in cross-sectional area change between upstream, across, and downstream-ROW cross-sections [(F 2,64) = 0.341, p = 0.73; (F2,18)= 0.980, p = 0.395]. Sediment generated during pipeline construction appeared to have moved beyond the physical confines of the study site, which limited the assessment of larger-scale geomorphic impacts. Furthermore, the 2014-2016 study period experienced only small (high-recurrence frequency) precipitation events, indicating the absence of large flows capable of significant morphologic change. To further explain differences in cross-section area change between LIDAR datasets, a linear regression model was used to assess the predictive value of nine variables: year of measurement, drainage area, drainage density, basin slope, upstream-, across-, downstream-ROW cross-section locations, percent bare soil in basin, percent mesquite in basin, total precipitation, and number of storms with average precipitation above 25 mm/hour. Though the amount of bare soil in the basin and the second study period (February 2015-July 2016) at least partially explained the changes in cross-section area, the model was not a strong predictor of morphologic change during the 2014-2016 study period. The majority of the variability in cross-sectional area change in the study basins remained unexplained.

I use video and material fragments to investigate the collapse of virtual and physical spaces as memories, lived environments, and digital interfaces become overlaid and interchangeable. I am interested in the capacity for technology to propose alternative strategies in which to engage with the world as we continue to extend ourselves in new and enduring methods. Seemingly unremarkable fragments offer new potentials in questioning meaning, worth, and care within spaces of downtime, boredom, and play. This document accompanies my thesis exhibition a window the color of her sunburn. It provides background information on selected fragments and residues from my own life alongside philosophical and art historical research, which informs my exhibition.

Ponds are common and abundant features in nearly all landscapes typical of European lowland landscapes yet research on freshwater biodiversity has traditionally focussed on larger waterbodies such as lakes and rivers. This has led to an increased need to understand and quantify the biodiversity associated with pond habitats to better inform the active conservation and management of these small waterbodies. This thesis examines the aquatic macroinvertebrate biodiversity (alpha, beta and gamma) and conservation value of 95 ponds in Leicestershire, UK, across a variety of urban and rural landscape types and at a range of spatial scales. In addition, the relative importance of local (physicochemical and biological) and spatial (connectivity) variables in structuring macroinvertebrate communities within ponds is investigated. At a regional scale, the greatest macroinvertebrate biodiversity and conservation value was recorded within meadow ponds compared to urban, agricultural and forest ponds. Spatially, ponds were highly physically and biologically heterogeneous. Temporally (seasonally), invertebrate communities were most dissimilar in meadow and agricultural ponds but assemblages were similar in urban and forest ponds. In urban landscapes, park ponds supported a greater diversity of invertebrates than other urban or garden ponds and typically had a greater conservation value. Garden ponds were the most taxon poor of those investigated. Perennial floodplain meadow ponds supported a greater biodiversity of invertebrates compared to ephemeral meadow ponds although conservation value was similar. Despite regular inundation from the River Soar, ephemeral ponds supported distinct communities compared to perennial meadow ponds. Aquatic macrophytes supported a higher diversity of taxa than other pond mesohabitats across all landscapes studied. Physicochemical factors were identified to be the dominant influence on macroinvertebrate assemblages although, a combination of local and spatial factors best explained the variation in community composition at a regional scale and for meadow ponds. Spatial factors were not identified to significantly influence urban pond communities. This study highlights the ecological importance and conservation value of ponds in rural and anthropogenically disturbed landscapes. Recognition of the significant contribution of ponds to freshwater biodiversity at regional and landscape scales is important for future conservation of pond habitats and will help focus and direct conservation strategies to where they are needed most.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Kyle Douglas-Mankin / Soil erosion is one of the most important of today’s global environmental problems. Over the past few decades, soil conservation practices were implemented to reduce soil erosion in the United States. However, excessive sediment still remains among the most prevalent water quality problems. Agricultural fields and in particular ephemeral gullies (EGs) are considered to be a major contributor of sediment. The overall goal of this study was to improve modeling utility to identify and quantify sources of sediment. Specific objectives were: (1) to develop and demonstrate a method of field-scale targeting using Soil and Water Assessment Tool (SWAT) and to use this method as a targeted, flexible approach to pay explicitly for sediment-yield reductions; (2) to evaluate topographic index models (Slope Area [SA], Compound Topographic Index [CTI], Slope Area Power [SAP] and Wetness Topographic Index [WTI]) and a physical-based model (Overland Flow Turbulent [OFT]) in predicting spatial EG location and lengths. Black Kettle Creek watershed was the focus of an innovative project to pay for modeled field sediment reductions. An Arc-Geographical Information System (GIS) tool bar was developed that post processed SWAT hydrologic response unit output to field boundaries and prepared maps of high-priority fields by sediment, total nitrogen, and total phosphorus and was demonstrated to be useful for field-scale targeting. Calibrated SWAT model was used to establish baseline sediment yields. Various Best Management Practices (BMPs) were simulated and payments to implement each BMP for a given field were calculated. This study helped to guide determination of appropriate farmer support payments and quantified the important influence of BMP type and site-specific conditions for use in targeting conservation practice funding to achieve maximum soil-loss reductions per dollar spent. Extreme care should be used in selecting the source of spatial model input data when using SWAT for field-level targeting. Automated geospatial models were developed in a GIS environment to spatially locate and derive length of EGs using topographic index and physical based models. EG predictions were better for the SA model among the four topographic index models tested. Individual calibration of topographic index model threshold for each application site was needed. An OFT model (physical based model), which utilized topography, precipitation, soil, landuse/landcover and SWAT-based runoff estimates, did not need individual site calibration, and may have broader applicability than empirical based models.

A tese DA IMENSIDÃO AO POEMA apresenta obras de arte e experimentos poéticos realizados entre os anos de 2014 e 2018, os quais exprimem uma busca intrinsecamente relacionada à imensidão. Incorporada a esta busca estão as produções de livros de artista, de poemas, instaurações, registro de caminhadas e relatos poéticos. Reunidos a este volume estão outros sete volumes compostos por livros de artista. Na busca pela imensidão foram abordadas as hipóteses de percepção da imensidão como elemento constitutivo de lugares e formador de não lugares, cuja análise desenvolveu conceitos tais como: heterotopia e atopia e sua relação com o tempo que pode coexistir permanentemente e de forma efêmera (heterocronia). Foram analisadas outras obras produzidas por outros artistas cuja composição e contextos se relacionam com os experimentos produzidos neste relato poético. / The dissertation FROM IMMENSITY TO POEM presents artworks and poetic experiments carried out between the years 2014 and 2018, which express a search intrinsically related to the immensity. Incorporated in this search are the productions of artist\'s books, poems, instaurations, documentation of walks and poetic narratives. Added to this volume are seven other volumes composed of artist\'s books. In the quest for immensity, the hypotheses of perception of immensity as a constituent of places and non-places were discussed, whose analysis developed concepts such as: heterotopy and atopy and their relationship withs time that can coexist permanently and in an ephemeral way (heterochrony). Artworks produced by other artists whose composition and contexts are related to the experiments produced in this poetic research were analyzed too.

Esta dissertação visa entender as implicações do projeto arquitetônico no momento da execução de obras efêmeras, bem como busca elucidar os paradigmas essenciais a este projeto frente ao estágio avançado de depredação dos meios naturais em que o planeta se encontra. Entretanto, ainda que com a escassez de referências bibliográficas sobre o tema, na busca por esse pensamento analisaremos três pavilhões de verão da Galeria Serpentine executados por arquitetos de grande importância no cenário atual acreditamos que o conceito em arquitetura fica plasmado na obra. A leitura desses objetos, organizados não verbalmente, necessita de um referencial capaz de elucidar a sintaxe do pensamento que o orienta, revelando através de dados icônicos e indiciais o repertório de seu projetista. Neste momento mostra-se fecunda a teoria da semiótica de Charles Sanders Peirce, não apenas para revelar o repertório do arquiteto e os paradigmas de projeto que o orientam, mas também para pesquisar de que maneira estes profissionais materializam seus pensamentos através da linguagem não-verbal da arquitetura. Por outro lado, o que se vê à exaustão em eventos comerciais é a utilização de semelhantes sistemas construtivos industrializados, dos quais o OCTANORM é o mais conhecido, o que garante a continuidade do processo moderno e a elevação da capacidade de montagem e desmontagem como valor principal da obra. As hipóteses aqui levantadas tomam estes sistemas como uma manifestação da continuidade e apontam para outras arquiteturas, ainda efêmeras, mas alheias a essa dinâmica e com especificidades que caracterizam um campo particular de estudo. A base epistemológica deste trabalho veicula muito a semiótica peirciana e a bibliografia fundamental que dá orientação à pesquisa tem origem na filosofia da arquitetura e na psicologia da percepção com diversos teóricos. / This dissertation intends to understand the architectural project implications in the moment of the execution of ephemeral works, and tries to elucidate the essential paradigms to this project due to the advanced stage of depredation found within the planets natural resources. However, even facing a bibliographic shortage on the theme, searching this thought, we will analyze three summer pavilions inside Serpentine Gallery, executed by well-known architects we believe that the concept in architecture remains in this work. The reading of these objects, non-verbally organized, needs a reference capable of elucidating the thought syntax that guides it, revealing the designer repertory through iconic and inkling data. In this moment, Charles Sanders Peirces theory is shown to be abundant, not only to reveal the architectural repertory and the projects paradigms that guide it, but also to find the way that these professionals turn their thoughts into matter through non-verbal architectural language. On the other hand, what is exhaustively seen throughout commercial events is the use of similar industrialized constructive systems, from which OCTANORM is the most known, what guarantees the continuity of the modern process and the elevation of the mounting an dismounting capability as the main value of the work. The hypotheses raised in here consider these systems as a manifestation of continuity and point to other architectures, still ephemeral, but disconnected to this dynamic and owners of specificities that characterize a particular field of study. The basis of this work, regarding the use of epistemology, features peircians semiotics a lot and, the fundamental bibliography, that gives the research an orientation, has its origin in the architecture philosophy and in the psychology of perception defended by many theorists.

Nas duas últimas décadas, o graffiti se impôs como um elemento visual das metrópoles brasileiras. Passou a povoar a rotina urbana e, num embate por espaços, vem disputando a visibilidade pública com as cores dos edifícios, as placas de sinalização e outros elementos da comunicabilidade urbana. E o faz mudando a sua proposta e original essência. Este trabalho procura documentar a trajetória do graffitti de meados da década de 1960 até às vésperas da conclusão da pesquisa, em 2011, acompanhando a sua transformação \"do subversivo ao consagrado\". Através da narrativa visual pontuada por uma seleção de 400 fotografias de autoria do pesquisador, destaca-se, em especial, a cidade de São Paulo, onde o trabalho dos grafiteiros vem despertando interesse mundial e não apenas entre adeptos, simpatizantes e editoras especializadas. O graffiti tem sido um interessante campo de estudo para críticos de arte, antropólogos, semiólogos, etc., porém, é na visualidade urbana que tem o maior impacto. / In the last two decades, graffiti has established itself as a visual element of the metropolis in Brazil. It became part of the urban routine, and in a dispute for space has been struggling for public visibility with building colors, traffic signs and other elements of urban communicability. And it does so by changing its intent and original essence. This paper seeks to document the trajectory of graffiti from the mid 1960s to the conclusion of the research, in 2011, following its transformation \"from subversive to acclaimed\". By means of a visual narrative marked by a selection of 400 photographs taken by the researcher, the city of São Paulo is emphasized, where graffiti is attracting worldwide attention and not only among supporters, sympathizers and specialized publishers. Graffiti has been an interesting field of study for art critics, anthropologists, semiologists, and scholars in general, but the greatest impact of this street art is on the urban scene.

Issu d’une famille d’artisans parisiens, loin des dynasties d’artistes qui émaillent l’époque moderne, Charles Michel-Ange Challe (1716-1778), peintre d’histoire, professeur de géométrie et de perspective à l’Académie royale, puis dessinateur de la Chambre et du Cabinet du roi, témoigne d’une émancipation professionnelle caractérisée. Parallèlement, la trajectoire personnelle de l’artiste, né de parents fort modestes, atteste une mobilité sociale certaine, marquée par nombre de reconnaissances tels que ses appartenances académiques, ses liens privilégiés avec la famille Nattier et la progression remarquable de sa situation économique, culturelle et sociale. Ponctué d’autant de chaos que de victoires, le parcours de Michel-Ange Challe, tantôt agissant, subordonné, contraint ou émancipé, éclaire à de nombreux égards, la situation des artistes parisiens au milieu du XVIIIe siècle. / Charles Michel-Ange Challe (1716-1778) began as an History painter, a professor of geometry and perspective at the Royal Academy in Paris, before being appointed as Dessinateur de la Chambre et du Cabinet du roi. He was born among a family of Parisian craftsmen, with no link with the numerous dynasties of artists flourishing during this era. The way he pursued his life attest to his outstanding professional emancipation. At the same time, the personal life of the artist, whose background was very modest, attest to a certain social mobility, marked by many recognitions such as his academic affiliations, his links with the Nattier family and the exceptional progress of his economic, cultural and social situation. Punctuated by as many chaos as victories, the career of Michel-Ange Challe, alternately acting, subordinate, forced or emancipated, illustrate in many ways the situation of the parisian artists in the mid of the 18th century.