Emerging "Structure-from-Motion" (SfM) photogrammetry techniques encourage faster, cheaper, and more accessible field methods for accurately reconstructing 3D topography. The SfM method consists of collecting sets of overlapping images of the ground surface with a point and shoot camera, and reconstructing surface topography from the images with developed software programs. This research develops and implements a SfM image acquisition method and post-processing workflow as a supplemental technique to the traditional total-station method to aid in monitoring sandbar change in Marble and Grand Canyons along the Colorado River in Arizona. Due to permitting in Grand Canyon National Park, a 4.9 m pole-mounted camera platform was used in this research to mimic the ground perspective of an aerial platform. This research presents an improved understanding of how the low-angle, pole-mounted camera platform affects image acquisition and ultimately 3D reconstructions of the surface topography. Models of ground surfaces always contain some degree of elevation error, or uncertainty. As such, elevation error models are needed to distinguish whether observed changes to topographic features (in this case sandbars) are real or simply due to elevation error. There are many ways to quantify multiple sources of elevation uncertainty, but in this study the sources of elevation uncertainty were considered to vary across the surface and were characterized accordingly. Especially in river environments with complex surface topography (e.g. steep cut banks), and roughness (e.g. vegetation), quantifying the spatially variable elevation uncertainty of the surface representation is critical for interpreting actual changes in surface topography over repeat surveys. This research: used the sandbar images collected in Marble and Grand Canyons with the pole-mounted camera platform to generate SfM, topographic models; calculated spatially variable surface uncertainty derived from slope and roughness using multiple statistical analyses; built an error model that was calibrated based upon the statistical analyses of the spatially variable surface uncertainty; Key findings of this research are: Densely vegetated topography results in high amounts of elevation uncertainty, and without additional information of the surface underlying the vegetation, the SfM tool is less operational in these areas; Bare, exposed topography with low to high slopes that are not covered in black shadows result in lower surface uncertainty, and are areas where SfM is an operational tool for studies of surface change. Complementing existing topographic sampling methods with more efficient and cost- effective SfM approaches will contribute to the understanding of changing responses of the topographic features. In addition, the development and implementation of SfM and corresponding amounts of elevation uncertainty for monitoring geomorphic change will provide a methodological foundation for extending the approach to other geomorphic systems world- wide.

Small wind turbines, and especially urban-mounted turbines which require no dedicated pole, have garnered great public enthusiasm in recent years. This enthusiasm has fueled widespread growth among energy conservationists, and estimates predict that the power produced nationally by small wind will increase thirty-fold by 2013. Unfortunately, most of the wind resources currently available have been designed for larger, rural-mounted turbines; thus, they are not well suited for this nascent market. A consequence of this is that many potential urban small wind turbine owners over-predict their local wind resource, which is both costly and inefficient. According to a recent study published by Encraft Ltd., small wind turbines mounted to buildings far underperformed their rural pole mounted counterparts. As a proposed solution to this problem, this project introduces the concept of a Web-based Wind Assessment System (WWAS). This system combines all the necessary resources for potential urban small wind turbine customers into a single web-based tool. The system also presents the concept of a modular wind measurement system, which couples with the WWAS to provide real-time wind data measurements. The benefits of the system include its ease of use, flexibility of installation, data accessibility from any web browser, and expert advice. The WWAS prevents potential clients from investing in a system that may not be viable for their location. In addition, a small wind turbine is designed in this project, which has a unique modular mounting system, allowing the same baseline wind turbine to attach to various structures using interchangeable mounting hardware. This includes such accessible urban structures as street lights, building corners, flag poles, and building walls, among others. This design also utilizes concepts that address some of the challenges associated with mounting small wind turbines to existing urban structures. These concepts include: swept tip blades and lower RPM to reduce noise; vibration suppression using rubber shims; a netted duct to protect wildlife; and a direct-drive permanent magnet generator to ensure low starting torque. Finally, the cost of this system is calculated using off-the-shelf components, which minimize testing and certification expense. This small wind turbine system is designed to be grid-connected, has a 6 foot diameter rotor, and is rated at 1 kW. This design features a unique modular interchangeable mounting system. The cost for this complete system is estimated to be $2,050. If a users' site has an average wind speed of 14 mph (6.5 m/s), this system will generate a return on investment in 8.5 years, leaving over 10 years of profit. The profit for this system, at this sample average wind speed, yields over $4,000 during its 20-year design life, which is a two-fold return on investment. This project has implications for various stakeholders in the small wind turbine market, including designers, engineers, manufacturers, and potential customers. Equally important is its potential role in guiding our future national--even global--energy agenda.