Research
My research objectives are to:
Some data I rely on for synthetic research:
Some representative questions that guide my research:
Current projects and future publications:
Research projects that will result in publications and opportunities to engage students in associated research and/or field work include:
Description of Representative Research
The recently published book (2015), Traditional Arid Lands Agriculture: Understanding the Past for the Future, is an example of the type of work I find rewarding and valuable. This book brings together scholars from the disciplines of archaeology, anthropology, agronomy, art, botany, geomorphology, paleoclimatology, and pedology. Each chapter considers four questions: what we don't know about specific aspects of traditional agriculture, why we need to know more, how we can know more, and what research questions can be pursued to know more. What is known is presented to provide context for what is unknown.
My dissertation is also an example of the type of research I continue to pursue. I identify and evaluate conceptual models (used by many disciplines) of human vulnerability to climatic hazards in arid and semi-arid regions. One such model asserts that people living in settlements with the highest population levels will be the most vulnerable to droughts. Using archaeological data from 535 settlements, tree-ring precipitation and streamflow reconstructions, modern climate data, and GIS analysis, I evaluate this model (and others) in the U.S. Southwest over a 250 year period. Contrary to expectations, I find that differences in settlement population levels did not influence vulnerability to drought. Evaluating another model, I find that people living in areas with the greatest potential resource productivity (near a perennial river or in an area of relatively high precipitation) were the most vulnerable to dry periods, contrary to expectations.
Results of this research have implications for modern studies of human vulnerability to climate change in dry climates and for our understanding of prehistory. For the present, these findings question existing expectations regarding where and under what conditions the impacts of a changing climate will be most severe. Identifying conditions that contribute to hazard vulnerability and impacts can direct climate change adaptation and mitigation efforts where they are most needed. For our understanding of the past, evaluating models of hazard vulnerability allow us to appraise arguments that rely on these models. For example, a late 1200s drought in the northern U.S. Southwest has been argued to have contributed to regional-scale depopulation because settlement population levels were higher at this time than during previous droughts. I find, however, no empirical support for the asserted relationship between high settlement population levels and increased vulnerability to drought. This finding questions linking the depopulation to changes in hazard vulnerability.
A “classic” archaeological problem I continue to investigate is the depopulation of the Phoenix Basin during the 15th century. Canal-damaging floods during the late 1300s and their impact on Hohokam irrigation agriculture are a prominent explanation of the depopulation. In American Antiquity (Ingram 2008) I reported results that challenge existing assumptions regarding the influence of flooding and drought on population change in the basin. I found that during the 775 through 1450 CE period, population growth rates increased as the frequency, magnitude, and duration of inferred flooding, drought, and streamflow variability increased. A long-term pattern of population increases associated with extreme streamflow events does not support the hypothesis that flooding was a catalyst for population decreases and the depopulation of Phoenix basin.
- Contribute insights toward understanding contemporary problems such as human vulnerability to climate change and social and ecological sustainability by investigating long-term human and environmental interactions.
- Advance understanding of classic archaeological problems (e.g., cultural transitions, regional depopulations, “collapses”) with regional-scale settlement and environmental data and innovative methods and analysis.
Some data I rely on for synthetic research:
- The Coalescent Communities Database is the most comprehensive source of settlement data available for precontact North American Southwest.
- Tree-ring reconstructions of precipitation and temperature developed at the Laboratory of Tree-Ring Research, University of Arizona.
- Long-term Vulnerability and Transformation Project data from the US Southwest and northern Mexico.
Some representative questions that guide my research:
- What factors influence the capacity of human societies to respond to environmental changes, and how can resilience and vulnerability to these changes be identified and managed?
- What strategies have been used by individuals (communities, regions) in the past to adapt to climatic hazards or other environmental changes?
- What is the relationship between population change (or the extent of social hierarchy, or governance, or environmental changes etc.) and periods of social stability and transformation?
Current projects and future publications:
Research projects that will result in publications and opportunities to engage students in associated research and/or field work include:
- NSF, Arctic Social Sciences program I am a member of the research team investigating resilience and vulnerability to climate change in the U.S. Southwest and the circumpolar North Atlantic region. I am currently the lead author on a paper examining the relationship between the periodicity of climatic hazards and social transformation in both regions. I would assist students to identify research questions that can be addressed with paleoclimatic, historic, and/or archaeological data from Greenland, Iceland, the Faroes Islands, Scotland, and the U.S. Southwest. This project is a collaboration between the Long Term Vulnerability and Socioecological Change project at ASU and the North Atlantic Biocultural Organization.
- NSF, Archaeology program I am continuing to contribute paleoclimatic and archaeological expertise to the interdisciplinary project, “Alliance and Landscape: Perry Mesa, Arizona in the Fourteenth Century.” Student projects associated with this grant could consider climatic influences on human behavior, evidence of conflict and alliance among people, and the legacies of human action on landscapes.
- Human Vulnerability to Climatic Hazards I (and interested students) will apply the methods and data I developed for evaluating the impact of demographic, environmental and other conditions on vulnerability to dry periods in other sub-regions of the U.S. Southwest. This will result in a number of studies appropriate for publication. I am currently working on two publications associated with my dissertation. I intend to submit one to American Antiquity and one to an international global environmental change journal.
- Book: “Corn and Cotton” I am a co-author on several chapters in Robert C. Hunt’s (Brandeis University) book, “Corn and Cotton,” in preparation. I have developed irrigated agriculture production model we use to simulate maize yield along the Middle Gila. Student contributions to this project could include using and refining the model to simulate yields among similar irrigation systems or examining the ethnographic record for sustainable (or unsustainable) practices associated with intensive subsistence agriculture in an arid region.
- Fieldwork I have opportunities to develop or assist students with field work in the U.S. Southwest (northern New Mexico) and/or the North Atlantic Islands of Iceland, Scotland, and Faroes. Potential field projects can be based on student interests and could range from culture-historical problems (historic and prehistoric) to analysis of the artifact collections of several overlooked museums.
Description of Representative Research
The recently published book (2015), Traditional Arid Lands Agriculture: Understanding the Past for the Future, is an example of the type of work I find rewarding and valuable. This book brings together scholars from the disciplines of archaeology, anthropology, agronomy, art, botany, geomorphology, paleoclimatology, and pedology. Each chapter considers four questions: what we don't know about specific aspects of traditional agriculture, why we need to know more, how we can know more, and what research questions can be pursued to know more. What is known is presented to provide context for what is unknown.
My dissertation is also an example of the type of research I continue to pursue. I identify and evaluate conceptual models (used by many disciplines) of human vulnerability to climatic hazards in arid and semi-arid regions. One such model asserts that people living in settlements with the highest population levels will be the most vulnerable to droughts. Using archaeological data from 535 settlements, tree-ring precipitation and streamflow reconstructions, modern climate data, and GIS analysis, I evaluate this model (and others) in the U.S. Southwest over a 250 year period. Contrary to expectations, I find that differences in settlement population levels did not influence vulnerability to drought. Evaluating another model, I find that people living in areas with the greatest potential resource productivity (near a perennial river or in an area of relatively high precipitation) were the most vulnerable to dry periods, contrary to expectations.
Results of this research have implications for modern studies of human vulnerability to climate change in dry climates and for our understanding of prehistory. For the present, these findings question existing expectations regarding where and under what conditions the impacts of a changing climate will be most severe. Identifying conditions that contribute to hazard vulnerability and impacts can direct climate change adaptation and mitigation efforts where they are most needed. For our understanding of the past, evaluating models of hazard vulnerability allow us to appraise arguments that rely on these models. For example, a late 1200s drought in the northern U.S. Southwest has been argued to have contributed to regional-scale depopulation because settlement population levels were higher at this time than during previous droughts. I find, however, no empirical support for the asserted relationship between high settlement population levels and increased vulnerability to drought. This finding questions linking the depopulation to changes in hazard vulnerability.
A “classic” archaeological problem I continue to investigate is the depopulation of the Phoenix Basin during the 15th century. Canal-damaging floods during the late 1300s and their impact on Hohokam irrigation agriculture are a prominent explanation of the depopulation. In American Antiquity (Ingram 2008) I reported results that challenge existing assumptions regarding the influence of flooding and drought on population change in the basin. I found that during the 775 through 1450 CE period, population growth rates increased as the frequency, magnitude, and duration of inferred flooding, drought, and streamflow variability increased. A long-term pattern of population increases associated with extreme streamflow events does not support the hypothesis that flooding was a catalyst for population decreases and the depopulation of Phoenix basin.
My efforts to use the past to inform the present are part of GHEA.
 Fieldwork at an Ohio Hopewell site. |
 I favor quantitative approaches to gain insights into long-term human-environmental interactions. |