Michael A. Urban

Catastrophic Human-Induced Change in Stream-Channel Planform and Geometry in an Agricultural Watershed, Illinois, USA

Abstract The adverse effects of channelization on the environmental quality of streams and rivers at a global scale are well documented, but the magnitude of human-induced changes in river systems relative to the efficacy of geomorphological processes has yet to be ascertained quantitatively. Stream channelization is a common feature of the agricultural landscapes of the midwestern United States. This study shows that channelization in the Embarras River basin of east central Illinois has altered stream channel and planform geometries to an extent that exceeds background rates of change for unchannelized reaches by one to two orders of magnitude. The average rate of change in channel position resulting from stream responses to channelization also greatly exceeds the average rate of change for unchannelized reaches, yet the spatial extent of stream adjustments to channelization is limited, and most straightened or relocated channels persist in their altered state for decades following channelization.

Perceptions of Wood in Rivers and Challenges for Stream Restoration in the United States

This article reports a study of the public perception of large wood in rivers and streams in the United States. Large wood is an element of freshwater aquatic ecosystems that has attracted much scientific interest in recent years because of its value in biological and geomorphological processes. At the heart of the issue is the nature of the relationship between scientific recognition of the ecological and geomorphological benefits of wood in rivers, management practices utilizing wood for river remediation progress, and public perceptions of in-channel wood. Surveys of students’ perceptions of riverscapes with and without large wood in the states of Colorado, Connecticut, Georgia, Illinois, Iowa, Missouri, Oregon, and Texas suggest that many individuals in the United States adhere to traditionally negative views of wood. Except for students in Oregon, most respondents considered photographs of riverscapes with wood to be less aesthetically pleasing and needing more improvement than rivers without wood. Analysis of reasons given for improvement needs suggest that Oregon students are concerned with improving channels without wood for fauna habitat, whereas respondents elsewhere focused on the need for cleaning wood-rich channels for flood risk management. These results underscore the importance of public education to increase awareness of the geomorphological and ecological significance of wood in stream systems. This awareness should foster more positive attitudes toward wood. An integrated program of research, education, and policy is advocated to bridge the gap between scientific knowledge and public perception for effective management and restoration of river systems with wood.

Values and Ethical Beliefs Regarding Agricultural Drainage in Central Illinois, USA

ABSTRACT While agriculture in the midwestern United States has often been associated with deleterious effects on stream ecology and geomorphology, identifying appropriate mitigation strategies requires an understanding of the values and ethical beliefs motivating such behavior. Fifty-five open-ended interviews with farmers in central Illinois reveal that environmental modifications such as agricultural drainage can be seen as a rational expression of local environmental valuation. Personal definitions of progressive or successful farming, aesthetic characteristics of the farm such as neatness and order, and ethical understandings of environmentally responsible behavior all drive farming decisions affecting the environment. Debate and dissent create a rich constellation of environmental values, which are constantly renegotiated. Illustrating the complex ways in which farmers perceive and interact with environmental systems allows for a better understanding of these important agents of change in agricultural environments.

Conceptualizing Anthropogenic Change in Fluvial Systems: Drainage Development on the Upper Embarras River, Illinois

While the geomorphic structure of many landscapes is materially molded, shaped and transformed by human practices, it is at the same time experienced and perceived through the mediation of cultural discourse and representation. The objective of this article is twofold: (1) to establish a conceptual framework for integrated analysis of human and geomorphic dimensions of landscape change; and (2) to illustrate the use of this framework in the assessment of a physical system severely affected by human agency. This perspective offers one way in which human agency can be synthesized and integrated into aspects of physical geography— specifically fluvial geomorphology— from both a conceptual and a pragmatic point of view. The upper Embarras River in east central Illinois, used as a case study, has been and continues to be physically affected by the cultural practice of agricultural drainage over the past century and a half.

The Changing Geography of the U.S. Water Budget: Twentieth-Century Patterns and Twenty-First-Century Projections

Persistent changes in temperature and precipitation patterns have dramatic effects on the availability of surface water for natural vegetation, streamflow, agricultural production, and human consumption. We use a combination of historical observational climate data and water budget equations to develop time-series and maps of twentieth-century water variables within the contiguous United States and compare these with anticipated twenty-first-century patterns projected by global climate models. The results graphically demonstrate regional variation in hydroclimatic trends: areas that experienced convergent actual (AET) and potential evapotranspiration (PET) rates during the twentieth century (such as the Great Lakes and Gulf South) witnessed long-term increases in available moisture, whereas areas with divergent rates (such as the Mid-Atlantic and Great Plains) had greater water deficits. Increasing temperatures through the twenty-first century will produce higher PET across the United States; areas where AET similarly escalates will maintain average moisture levels within twentieth-century ranges, but where AET does not correspondingly increase, as in much of the South and West, average conditions will be comparable to those of extreme twentieth-century droughts. The findings highlight the importance of a regional approach to environmental change, as the impacts of climate on water in the United States will be spatially uneven.

Integrating downscaled CMIP5 data with a physically‐based hydrologic model to estimate potential climate change impacts on streamflow processes in a mixed‐use watershed

&NA; Climatic changes have altered surface water regimes worldwide, and climate projections suggest that such alterations will continue. To inform management decisions, climate projections must be paired with hydrologic models to develop quantitative estimates of watershed scale water regime changes. Such modeling approaches often involve downscaling climate model outputs, which are generally presented at coarse spatial scales. In this study, Coupled Model Intercomparison Project Phase 5 climate model projections were analyzed to determine models representing severe and conservative climate scenarios for the study watershed. Based on temperature and precipitation projections, output from GFDL‐ESM2G (representative concentration pathway 2.6) and MIROC‐ESM (representative concentration pathway 8.5) were selected to represent conservative (&Dgr;C) and severe (&Dgr;S) change scenarios, respectively. Climate data were used as forcing for the soil and water assessment tool to analyze the potential effects of climate change on hydrologic processes in a mixed‐use watershed in central Missouri, USA. Results showed annual streamflow decreases ranging from −5.9% to −26.8% and evapotranspiration (ET) increases ranging from +7.2% to +19.4%. During the mid‐21st century, sizeable decreases to summer streamflow were observed under both scenarios, along with large increases of fall, spring, and summer ET under &Dgr;S. During the late 21st century period, large decreases of summer streamflow under both scenarios, and large increases to spring (&Dgr;S), fall (&Dgr;S) and summer (&Dgr;C) ET were observed. This study demonstrated the sensitivity of a Midwestern watershed to future climatic changes utilizing projections from Coupled Model Intercomparison Project Phase 5 models and presented an approach that used multiple climate model outputs to characterize potential watershed scale climate impacts.

Where is River City, USA? Measuring Community Attachment to the Mississippi and Missouri Rivers

This paper attempts to determine the location of towns self-identifying as metaphorical “River Cities” through quantitative methods informed by concepts of place attachment. Relative levels of river-oriented community attachment are measured by a frequency analysis of certain river-related terms in the names of businesses located in 213 U.S. counties adjacent to the Missouri and Mississippi rivers. Population-adjusted frequencies of the terms “river city,” “river cities,” “river town,” “big river,” “great river,” “Missouri River,” and “Mississippi River” in business names are used as proxy measures of community attachment to the river. The mapped results identify regional concentration and variation in river-centered community identity. Contextualized within the place attachment literature, these results suggest that the importance of big rivers to collective sentiment, self-presentation, image, and identity varies greatly from place to place.

In Defense of Crappy Landscapes (Core Tenet #1)

Many landscapes abused, degraded, despoiled, or otherwise impacted by people carry the stigma of being somehow unnatural and are overlooked by physical geographers. While some human impacts intentionally reshape environments, other traces result from concussive ripples generated as human forces resonate throughout biophysical systems. An explicit focus on environmental problems associated with the increasing imprint of human agency augments our ability to delineate both historical problems and to manage future challenges. An even more compelling rationale is that these composite environments more accurately represent how most systems function. Acknowledging social and biophysical forces, Critical Physical Geography reorients our science away from the pristine and centralizes the tainted. It reasserts the practical and philosophical importance of “crappy landscapes” to the future of Geography and environmental science.

An integrated modeling approach for estimating hydrologic responses to future urbanization and climate changes in a mixed-use midwestern watershed

Future urban development and climatic changes are likely to affect hydrologic regimes in many watersheds. Quantifying potential water regime changes caused by these stressors is therefore crucial for enabling decision makers to develop viable environmental management strategies. This study presents an approach that integrates mid-21st century impervious surface growth estimates derived from the Imperviousness Change Analysis Tool with downscaled climate model projections and a hydrologic model Soil and Water Assessment Tool to characterize potential water regime changes in a mixed-use watershed in central Missouri, USA. Results for the climate change only scenario showed annual streamflow and runoff decreases (-10.7% and -9.2%) and evapotranspiration increases (+6.8%), while results from the urbanization only scenario showed streamflow and runoff increases (+3.8% and +9.3%) and evapotranspiration decreases (-2.4%). Results for the combined impacts scenario suggested that climatic changes could have a larger impact than urbanization on annual streamflow, (overall decrease of -6.1%), and could largely negate surface runoff increases caused by urbanization. For the same scenario, climatic changes exerted a stronger influence on annual evapotranspiration than urbanization (+3.9%). Seasonal results indicated that the relative influences of urbanization and climatic changes vary seasonally. Climatic changes most greatly influenced streamflow and runoff during winter and summer, and evapotranspiration during summer. During some seasons the directional change for hydrologic processes matched for both stressors. This work presented a practicable approach for investigating the relative influences of mid-21st century urbanization and climatic changes on the hydrology of a representative mixed-use watershed, adding to a limited body of research on this topic. This was done using a transferrable approach that can be adapted for watersheds in other regions.

Three-dimensional measurement of river turbulence

Approaches to understanding the mechanical processes shaping river channels have historically been l…