Graduation date: 1985

This study of a portion of Oregon's Lincoln County coast describes the physical limitations to land use of the various landforms in the study area. Seven major landform types comprise the study area: beaches, active dunes, stabilized dunes, marsh land and tidal flats, marine terraces, basaltic headlands, and uplands. Descriptions and evaluations of their physical characteristics, distribution, geologic and and engineering characteristics, and potentially hazardous processes are contained in the maps, figures, and text.

There are extensive empirical studies on the impacts and effectiveness of Smart Growth policies; however, very few of them consider the perspective of individual decision makers and, to this author's knowledge, none have studied developers as location-aware decision-making agents. This study tries to fill this gap partially by assessing the impacts of Portland's smart growth policies on developers' location choice behavior with developer-based location choice models. The dissertation has two purposes. By assessing the impacts of Smart Growth policies on individual home developer's location choice, it provides a micro- and behavioral foundation for the understanding of Smart Growth policies. As a bi-state metropolitan area located on the border between Oregon and Washington, the Portland region provides a unique environment that allows my research to examine whether home developers react to Smart Growth policies differently in the two states with different land use policy systems. The dissertation also aims to create a developer-based land development forecast model, which can be used as a scenario analysis tool for the Portland region's long-term land use and transportation planning. Besides the developer location choice model mentioned above, the components of this comprehensive developer-based land development model also include a time series regression model that predicts annual new housing supply in the region and a model that synthesizes housing projects in a forecast year. The study shows that home developers in the Portland metropolitan area are sensitive to most Smart Growth policies that have been implemented in the region, but they react to them differently across the border between Oregon and Washington. Single-family home (SFH) and multi-family home (MFH) developers show different preferences for location attributes. The most significant predictors of where a developer will choose to locate a project are the locations of previous projects. After controlling for all of the other factors discussed above, there remains a strong preference for developing SFH units outside of the UGB in both Oregon and Washington sides of the Portland metropolitan area. Latent class models have been developed to detect taste variations among home developers in the SFH and MFH markets separately. Estimation results show clear taste variations across developers and housing projects with respect to site attributes in their location choice. With other variables in the segmentation model being the same, project size provides a better fit to the data than developer size, indicating that developers have taste variations among their different projects. Large size SFH projects developed by contractor-owners are more likely to be within the UGB and their locations tend to have higher residential density, housing diversity, transportation accessibility, road density, and land price. With most MFH projects within the UGB, estimation results show that large size MFH projects prefer the locations with higher residential density, housing diversity, mixed use, road density, land price, average household income, and proportion of young and middle age households. The three-step new housing supply and location choice forecast model seem to be able to capture the basic trend of housing market and land development in the Portland region. Three different aggregate housing supply forecast models, an conditional time series regressive model, a unconditional time series regression model, and an auto-regression integrated moving average (ARIMA) model were tested and their advantages and disadvantages were discussed. Both the SFH and MFH project synthesis models can simulate housing projects well for a forecast year. Three location choice models were developed to allocate synthesized housing projects into space. The three models are characterized separately as: (1) assumed market homogeneity and atomization of development projects; (2) deterministic market segmentation and synthesis of projects by size; and (3) probabilistic market segmentation and synthesis of projects by size, using a latent class approach. Examination of forecast results shows that all three models can successfully capture the basic spatial pattern of housing development in the region; however, the spatial distribution of MFH development is lumpier and more unpredictable. While Models 2 and 3 are more sophisticated and make more sense from a theoretical perspective, they do not return better forecast results than Model 1 due to some practical issues. Models 2 and 3 would be expected to perform better when those practical issues are solved, at least partially, in future research.

Street layout and design, once established, are then not easily changed. Urban form affects community development, livability, sustainability, and traffic safety. There has been an assumed relationship between urban form and traffic safety that favors designs with less through streets to improve safety. An empirical study to test this assumed relationship was carried out for crash data for Portland, Oregon. This thesis presents an empirical methodology for analyzing the relationship between urban form and traffic safety utilizing a uniform grid for the spatial unit. Crashes in the Portland, Oregon city limits from 2005-2007 were analyzed and modeled using negative binomial regression to study the effect of urban form and street layout through factors on exposure, connectivity, transit accessibility, demographic factors, and origins and destinations. These relationships were modeled separately by mode: vehicle crashes, pedestrian and bicycle crashes. Models were also developed separately by crash type and by crash injury severity. The models found that urban form factors of street connectivity and intersection density were not significant at 95% confidence for vehicle and pedestrian crash rates, nor for different crash severity levels, indicating that high connectivity grid street layout may have comparable safety to loops and lollipops, in contrast to results in earlier studies. Elasticity for all models was dominated by VMT increases. Business density, population and transit stops were also significant factors in many models, underlining the importance not only of street layout design, but also planning to direct development to influence where businesses, employment, and housing will grow and handle traffic volumes safely.

American urban neighborhoods are a patchwork; the spatial arrangement of types is a reflection of the dominant transportation technology at the time of their development. The earliest suburban areas were made accessible by fixed route systems such as the electric streetcar, followed by the widespread adoption of the automobile; each transportation epoch resulted in characteristic patterns of land use. This study uses aerial photographic coverage of Portland, Oregon from the years 1925, 1936, and 1945, a time of decline for the once popular trolley lines and dramatic increase in automobile usage, to monitor change within the residential areas of Portland's east side over a twenty year period. Classic economic models of the time acknowledged transportation as a force shaping the city; modem ideas in urban planning such as Traditional Neighborhood Design and Transit Oriented Development look to pre-automobile urban form as a means to reduce automobile use and its negative implications. This study uses variables of housing density and street connectivity derived from the aerial photography; the measured values of these variables are then considered for their spatial and temporal distribution using statistical comparisons. The results are compared to ideas within the urban models and current thinking about urban morphology. While generally consistent with the expected patterns, deviations and differences between the two variables are considered for their implications. Models offer a simplified version of the growth of American cities, considering only a few of the many aspects of a dynamic environment. By isolating on these variables of density and connectivity, a greater understanding of their role in arriving at the modem residential urban environment may be reached, and this understanding can add to the discourse in current planning debates.

The Calapooia River, a major tributary of the Willamette River in western Oregon, is a watershed typical of many found in the Willamette Basin. Public and private forested lands occur in the steep Upper Zone of the watershed, mixed forest and agriculture lands are found in the Middle Zone, and the Lower Zone of the watershed is comprised primarily of grass seed agriculture on relatively flat topography with poorly drained soils. High levels of dissolved nitrogen (DN) have been identified as a water-quality concern within the Calapooia River. To gain a better understanding of the relationship between landuse/landcover (LULC), soil drainage, and DN dynamics within the watershed on a seasonal basis, we selected 44 sub-basins ranging in size between 3 and 33 km² for monthly synoptic surface water-quality sampling from October 2003 through September 2004. We selected an additional 31 sample locations along the length of the Calapooia River to determine relative influence of the 44 sub-basins on DN concentrations in the river. T-tests were used to analyze differences between zones (Upper, Middle and Lower) and regression analysis was used to determine relationships between DN and LULC or soil drainage class. The agriculture-dominated sub-basins had significantly higher (< 0.05) DN concentrations than the predominantly forested sub-basins. Winter concentrations of nitrate-N were 43 times higher in agriculturally dominated sub-basins than in forested sub-basins, whereas in the spring, the difference was only 7-fold. High DN concentrations associated with the predominantly agriculture sub-basins were substantially reduced once they mixed with water in the Calapooia River, highlighting the likelihood that water draining the relatively nutrient-poor, forested sub-basins from the Upper Zone of the watershed, was diluting DN-rich water from the agriculture sub-basins. Relationships between DN and agriculture, woody vegetation or poorly drained soils were moderate to strong (0.50 < R² > 0.85) during the winter, spring and summer seasons. Results indicated an exponential increase in DN concentration when proportion agriculture or poorly drained soils increased, whereas an increase in woody vegetation was related to an exponential decrease in DN concentration. The high variability in DN concentration in the agriculture-dominated sub-basins suggests factors in addition to LULC and poorly drained soils influence DN in surface water. Seasonal relationships were developed between DN and proportion of poorly drained soils, agriculture, and woody vegetation at differing scales (10 m, 20 m, 30 m, 60 m, 90 m, 150 m, 300 m, and entire sub-basin), which we defined as Influence Zones (IZs), surrounding the stream network. Correlations between DN and proportion LULC or poorly drained soil at each IZ were analyzed for significant differences (p-value < 0.05) using the Hotelling-Williams test. Our results show strong seasonal correlations (r > 0.80) between DN and proportion of woody vegetation or agriculture, and moderate-to-strong seasonal correlations (r > 0.60) between DN and proportion of sub-basins with poorly drained soils. Altering scale of analysis significantly changed correlations between LULC and DN, with IZs < 150 m generally having higher correlations than the sub-basin level. In contrast, DN correlations with poorly drained soil were generally higher at the sub-basin scale than the 60- through 10-m IZs during winter and spring. These results indicate that scale of analysis is an important factor when determining relationships between DN concentration and proportion LULC or poorly drained soils. Furthermore, seasonal shifts in significant differences among IZs for correlations between LULC and DN suggest land management proximity and its influence on DN concentration changes temporally. DN relationships with poorly drained soil suggest that during winter and spring, when rainfall is highest, sub-basin scale soil drainage properties have a greater influence on DN than soil properties within IZs in close proximity to the stream network. / Graduation date: 2006

The purposes of this study were: 1) to review the land use history of Oak Creek watershed since European settlement. And 2) to consider the human-caused impacts and their effects associated with different land uses. The study area was classified into three land use patterns: residential, agricultural, and forested areas. Since the European settlement in the mid 1840's, the Oak Creek watershed has experienced changes of land use simultaneous with the development of the city of Corvallis and its vicinity. Associated with this, different impacts have occurred on riparian areas. By and large, these impacts were inherent to each land use. / Graduation date: 1993

Between 1845 and 1980 the Portland waterfront between southwest Washington and Clay Streets, east of Front Street, metamorphosed from wilderness to trade center, to highway, to inner-city vacant lot. No place in Portland has more graphically illustrated the rapidly changing forces of the modern age in which the city has grown. For much of its history this stretch of waterfront was mired in law suits. The struggles centered on public versus private ownership. Originally dedicated as public property, but left unimproved by the city, the waterfront was usurped by private investors. Eventually, private owners allowed their property to decay prompting the public to encourage improvements. The legal battles even became reversed as private investors sought to force the sale of the waterfront to the city. Through all the confusion of legal battles this stretch of waterfront played a central role in the development and identity of Portland. It has finally become, undisputed public territory. The tension and greed of private investment have been replaced by the lack of municipal funds for aesthetic improvement and have left this stretch of land, a potentially fine and important urban park, a vacant lot.

Urban water use arises from a mix of scale-dependent biophysical and socioeconomic factors. In Portland, Oregon, single-family residential water use exhibits a tightly coupled relationship with summertime weather, although this relationship varies with land use patterns across households and neighborhoods. This thesis developed a multilevel regression model to evaluate the relative importance of weather variability, parcel land use characteristics, and neighborhood geographic context in explaining single-family residential water demand patterns in the Portland metropolitan area. The model drew on a high-resolution panel dataset of weekly mean summer water use over five years (2001-2005) for a sample of 460 single-family households spanning an urban-to-suburban gradient. Water use was found to be most elastic with respect to parcel-scale building size. Building age was negatively related to water use at both the parcel and neighborhood scale. Half the variation in water use can be attributed to between-household factors. Between-neighborhood variation exerted a modest but statistically significant effect. The analysis decomposed household temperature sensitivity into four components: a fixed effect common to all households, a household-specific deviation from the fixed effect, a separate extreme heat effect, and a land use effect, where lot size exaggerated the effect of temperature on water use. Results suggested that land use planning may be an effective non-price mechanism for long-range management of peak demand, as land use decisions have water use implications. The combined effects of population growth, urbanization, and climate change expose water providers to risk of water stress. Modeling fine-grain relationships among heat, land use, and water use across scales plays a role in long-range climate change planning and adaptation.

Local food networks are often defined as presenting a variety of alternative food production, consumption, and distribution practices to the conventional food system such as community-supported-agriculture, farmers markets, and community gardens. Local food initiatives are commonly proposed as a model for the future of sustainable agriculture, and in the region of Portland, Oregon the abundance of such alternative venues results from the area's natural surroundings and smart planning. The region is host to 39 farmers markets and Portland is often hailed as one of the country's most sustainable cities. This study examines the role of local food networks in preserving agricultural land uses and livelihoods in Washington County, Oregon, a rapidly growing county adjacent to the city of Portland. I focus on small-scale agricultural landscapes where the producer sells at farmers markets or through community supported agriculture (CSAs). I explore farmers' concerns about urbanization and farmland preservation, their relationship to urban markets, motives to become a farmer, engagement with the surrounding environment, and their difficulties participating in local food networks. In addition, I explore farmers market managers' insights into the development of local food networks and how they see their markets supporting small-scale farmers. In a survey of consumers I examine consumer motives to `buy local' and consumer concerns about farmland preservation. The research is qualitative and explores: 1) the processes shaping the development of local food networks; 2) how particular ideas and images of nature and the countryside inform both consumer desires to purchase from farmers selling locally and; 3) how those same images of nature and the countryside inform and motivate people to become farmers participating in local food networks. In so doing, I argue that the networks that sustain urban and rural systems are important in understanding the development of local food networks, and that the preservation of economically and culturally important agricultural lands in Washington County depends on a diversity of opinions and rural narratives in order to preserve small-scale sustainable farmlands close-in to cities. The conclusion is that local food sold through alternative venues can be used as a means to preserve and develop specific and manageable farm sites and agricultural land uses but the impact is limited. Large scale impacts on agricultural land uses and livelihoods will depend on planners and advocates agreeing on policies that encompass a diversity of opinions, land uses, and land managers, while understanding the array of networks beyond the city that sustain both urban and rural systems.