Alexander W Hall

ESSA Technologies

Complexity and uncertainty are inherent in social-ecological systems. Although they can create challenges for scientists and decision makers, they cannot be a reason for delaying decision making. Two strategies have matured in recent decades to address these challenges. Systems thinking, as embodied by conceptual modeling, is a holistic approach in...

Background/Question/Methods Buffelgrass (Pennisetum ciliare) is spreading throughout the southwestern United States creating a risk of fire in a system poorly adapted to it. This fire risk threatens native ecosystems and human properties. We created a decision support model for the wildland urban interface north of Tucson, AZ, to address the leve...

Physical inactivity and associated co-morbidities such as obesity and cardiovascular disease are estimated to have large societal costs. There is increasing interest in examining the role of the built environment in shaping patterns of physical activity. However, few studies have: (1) simultaneously examined physical activity for leisure and utilit...

There is increasing interest in examining the influence of the built environment on physical activity. High-resolution data in a geographic information system is increasingly being used to measure salient aspects of the built environment and studies often use circular or road network buffers to measure land use around an individual's home address....

Northwest British Columbia, Canada, a sparsely populated and largely pristine region, is targeted for rapid industrial growth owing to the modernization of an aluminum smelter and multiple proposed liquefied natural gas (LNG) facilities. Consequently, air quality in this region is expected to undergo considerable changes within the next decade. In...

This document provides a series of conceptual models and supporting information/evidence that illustrates the interaction between migratory birds and human development in the oil sands region of Canada.

Logistic regression models predicting 'walking for leisure 15 minutes or less per day' by land use characteristics assessed with 1 km network and circular buffers. The data provided present the results of logistic regression models predicting 'walking for leisure 15 minutes or less per day' by land use characteristics assessed with 1 km network and...

Logistic regression models predicting 'walking for errands less than 1 hour per week' by land use characteristics assessed with 1 km network and circular buffers. The data provided present the results of logistic regression models predicting 'walking for errands less than 1 hour per week' by land use characteristics assessed with 1 km network and c...

Trends in climatic and hydrologic data from the Rio Grande and Pecos River basin are analyzed over an approximately 40-year period (1960 to 2000). Mann-Whitney tests for changes between halves of the record and between more recent decades, and Mann-Kendall tests for trend over the 40 years of record, are applied to monthly averages from 35 temperat...

The Arctic is one region where the effects of global climate change are expected to be easy to observe. This study identifies regions in the circumpolar Arctic that have experienced similar changes in the seasonal cycle of temperature and precipitation over recent decades. Data from Arctic and northern nations have been compiled to form a new data...