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At least 109 records · Page 6

Urban Dynamics: Analyzing Land Use Change in Urban Environments

In FY99, the Earth Resource Observation System (EROS) staff at Ames continued managing the U.S. Geological Survey's (USGS) Urban Dynamics Research program, which has mapping and analysis activities at five USGS mapping centers. Historic land use reconstruction work continued while activities in geographic analysis and modeling were expanded. Retrospective geographic information system (GIS) development - the spatial reconstruction of a region's urban land-use history - focused on the Detroit River Corridor, California's Central Valley, and the city of Sioux Falls, South Dakota.

Acevedo, William↗

Policy Document on Earth Observation for Urban Planning and Management: State of the Art and Recommendations for Application of Earth Observation in Urban Planning

A policy document on earth observation for urban planning and management resulting from a workshop held in Hong Kong in November 2006 is presented. The aim of the workshop was to provide a forum for researchers and scientists specializing in earth observation to interact with practitioners working in different aspects of city planning, in a complex and dynamic city, Hong Kong. A summary of the current state of the art, limitations, and recommendations for the use of earth observation in urban areas is presented here as a policy document.

Nichol, Janet↗

Quantifying Changes in Urban Albedo with NASA Earth Observations to Reduce the Urban Heat Island Effect in Cambridge, Massachusetts

Elevated temperatures resulting from the urban heat island (UHI) effect can have widespread impacts on human health, infrastructure, and ecosystems. These impacts can be exacerbated by changes in climate and extreme variation in regional temperature. By 2030, experts expect Cambridge, Massachusetts will experience warmer than average temperatures, more heat waves, and triple the number of abnormally warm days above 90°F per year. The NASA DEVELOP Program partnered with the City of Cambridge’s Community Development Department and the American Geophysical Union’s Thriving Earth Exchange to inform ongoing efforts aimed at reducing the impacts of urban heat in the city of Cambridge. The team used scenes obtained from High Resolution Orthoimagery and the National Agriculture Imagery Program in conjunction with building footprint data, to calculate rooftop albedo between 2008 and 2018. Using these results, maps displaying building-specific variation in albedo across Cambridge were created. A nighttime land surface temperature (LST) record for June, July, and August between 2003 and 2019 was constructed using the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) nighttime LST product. Lastly, temperature anomalies were calculated for Cambridge using seasonally averaged nighttime LST values obtained from Aqua MODIS to display ‘hot spots’ for summers between 2004 and 2019. The results of this project were then incorporated into an interactive ArcGIS Dashboard. This work will allow end users to explore spatial and temporal trends in albedo, nighttime LST, and temperature anomalies to assess whether the City of Cambridge is successfully reducing the effects of UHIs.

NASA DEVELOP↗

Wichita Climate II: Quantifying and Mapping Urban Heat to Inform Equitable and Sustainable Urban Planning Initiatives in Wichita, Kansas

Extreme heat is the deadliest weather-related event in the United States, as well as one of the least discussed. Climate change has raised the frequency, intensity, and duration of severe heat events. The built, urban environment is often hotter than neighboring rural areas due to a denser concentration of pavement, metal and other building materials absorbing and retaining heat, as well as a low amount of vegetation – creating a phenomenon commonly known as the urban heat island effect. This effect contributes to a wide range of public health issues, associated with heat strokes, dehydration, loss of work productivity, decreased learning, respiratory difficulties, and heat-related mortality. The average summer temperature in Wichita has increased 1.3 degrees (F) since 1970, and the number of days over 100 degrees (F) has historically increased, from 40 days in 1934 to 53 days in 2011.

Ritisha Ghosh↗

Huntsville Urban Development II: Utilizing NASA Earth Observations to Map the Urban Heat Island and Evaluate Vulnerability in Huntsville, Alabama

Huntsville, Alabama has seen a boom in growth over recent years. One consequence of this urban expansion is the exacerbation of the Urban Heat Island (UHI) effect across the city. This project identified the areas within Huntsville the greatest potential for heat reduction and community health benefits from tree-planting efforts. The team created maps of land surface temperature (LST), the normalized difference vegetation index (NDVI), and the normalized difference built-up index (NDBI) over June through August from 2019 to 2022 using data from ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station, Landsat 8 Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS), Landsat 9 OLI-2 and TIRS-2. The team identified areas with high LST, low NDVI, and high NDBI as areas with the greatest potential for heat reduction via tree-planting. Social factors relating to age, race, income, and self-reported health were adapted from Tree Equity Score to map community need for tree cover. When combining social with environmental factors, the team determined areas with the greatest potential for UHI mitigation: west-central and north downtown Huntsville. The team’s partner organization, the City of Huntsville, can use this priority map to guide their future tree-planting, and weigh the factors assessed according to their preference.

James Karroum↗

Traffic Signal Control for Large-Scale Urban Traffic Networks: Real-World Experiments using Vision-Based Sensors

Effective control of traffic signals plays a critical role in ensuring smooth vehicle flow in urban areas. Expertly engineered traffic signal controllers can considerably minimize travel delays and enhance sustainability. In this paper, the team proposes the Model Predictive Control (MPC) traffic signal control strategy using real-time traffic flow data from a vision-based camera as feedback information. Also, a realistic signal timing plan that considers National Electrical Manufacturers Association (NEMA) constraints has been developed to be applied to real-world scenarios. The primary aim is to reduce the number of vehicles across all links in the controlled area, thereby optimizing traffic flow and reducing energy consumption. To validate the proposed method, several real-life experiments were conducted at 24 intersections in Chattanooga, Tennessee, by collaborating with traffic field engineers. These experiments demonstrated significant performance improvements in comparison to the existing method.

data processing↗

Analysis of Interactions Between Urban Air Mobility (UAM) Operations and Conventional Traffic in Urban Areas: Traffic Alert and Collision Avoidance System (TCAS) Study for UAM Operations

This paper presents results on potential interaction effects from UAM (Urban Air Mobility) operations integrated into current operational scenarios by evaluating if/where/how Traffic alert and Collision Avoidance System (TCAS) alerts are triggered on-board commercial aircraft. A range of operational scenarios are evaluated with combinations of UAM vehicle route, speed, altitude, and direction along the DFW (Dallas-Fort Worth) "spine route." The effect of UAM altitude uncertainty on the above is also explored. The analysis was done for both South flow and North flow configurations of DFW. When UAM operations are deterministic, no TCAS RAs (Resolution Advisories) are issued. However, UAM altitude uncertainties point out geographic areas of concern with the associated severity of interactions.

Airspace↗

Model Predictive Control for Urban Traffic Signals with Stability Guarantees

Traditional traffic signal control focuses more on the optimization aspects whereas the stability and robustness of the closed-loop system are less studied. This paper aims to establish the stability properties of traffic signal control systems through the analysis of a practical model predictive control (MPC) scheme, which models the traffic network with the conservation of vehicles based on a store-and forward model and attempts to balance the traffic densities. More precisely, this scheme guarantees the exponential stability of the closed-loop system under state and input constraints when the inflow is feasible and traffic demand can be fully accessed. Practical exponential stability is achieved in case of small uncertain traffic demand by a modification of the previous scheme. Simulation results of a small-scale traffic network validate the theoretical analysis.

ADVANCED PROPULSION SYSTEMS,MATHEMATICS AND COMPUT↗

Demographic Microsimulator for Integrated Urban Systems: Adapting Panel Survey of Income Dynamics to Capture the Continuum of Life

Agent-based models (ABMs) in transportation modeling simulate activity and travel decisions at the disaggregate level of households and individuals. To do this, ABMs require detailed and realistic information on agents’ socioeconomic and demographic characteristics. Various synthetic population generators have been proposed to address this need. However, most of those currently in practice are cross-sectional in nature and do not account for the dynamics within households and individuals as they progress through life events over time. This is a major shortcoming, as literature has shown that transportation decisions are affected by the transition between and co-occurrence of life cycle events. While some demographic evolution simulators have been proposed to address this issue, they are developed using cross-sectional data and capture only a small set of life cycle events and their interdependence. Addressing these drawbacks, we propose a demographic microsimulator (DEMOS) that captures the “continuum of life” by considering a range of household- and individual-level life cycle events. DEMOS is developed using the Panel Survey of Income Dynamics, one of the world’s longest-running longitudinal surveys. The DEMOS submodels consider key life cycle events that are influenced by agents’ demographic variables. DEMOS is applied to evolve the population of the San Francisco Bay Area over a 9-year horizon. Results demonstrate how DEMOS generates life trajectories and how DEMOS outputs match the observed demographic trends. DEMOS is expected to enable longitudinal analysis in the context of ABMs and expand ABMs analyses relating to dynamic processes such as household-level vehicle transactions.

Demographic evolution↗