Climate Change Projections for the United States Midwest

Environmental and societal factors such asair quality, water quality andavailability, land use changes andexpanding urbanization are alreadyaffecting human health and welfare,agriculture, and natural ecosystems in theMidwestern United States. Over thiscentury, these existing stresses willlikely be exacerbated by climate changesresulting from human activities. It isessential that policy decisions aimed atpreserving the well-being of a region beinformed by a good understanding of theregion's climate, how climate might change,and the uncertainties inherent in futureprojections. Recent updates in climatemodeling expertise and an expanded view ofpossible non-intervention emissionscenarios have narrowed the range of changethat can be expected over the Midwestthroughout the next century in some ways,while broadening it in others. In contrastto previous studies, which generallyconsider a mid-range scenario for futureemissions, this study presents the range ofchange that would result from low to highscenarios for climate change. In this waywe account for uncertainties inanthropogenic forcing on climate change inthe region and quantify the potentialeffects of human actions on future climate.This analysis also combines the latestclimate model projections with historicalrecords of observed climate over the pastcentury, effectively placing potentialchanges in extreme event frequencies suchas heavy rainfall events and temperaturethreshold exceedances within the context ofobserved variability over the past century.The purpose of this study is to provide anupdated picture of the potential impacts ofclimate change on the Midwest to inform theimpact assessment and policy developmentcommunity. From the magnitude of thechanges projected by this study, it isclear that these must be included in futurepolicy decisions in order to ensure thesuccessful adaptation and survival ofexisting human and natural systems in theMidwest.     

TRANSITIONS IN MIDWESTERN GROUND WATER LAW1

ABSTRACT: The evolution of ground-water law in eight states in the Midwest (Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio, and Wisconsin) is examined, and a review of transitions in ground-water doctrines is presented. Two underlying themes in changing ground-water management are communicated. First, ground-water law is evolving from private property rules of capture based on the absolute ownership doctrines to rules requiring conservation and sharing of ground water as a public resource. Second, in both courts and state legislatures, a proactive role of ground-water management is emerging, again, with an emphasis on sharing. Both of these trends are apparent in the Midwest. In the last decade midwestern states have (1) seen significant shifts in court decisions on ground-water use with greater recognition of the reciprocal or mutually dependent nature of ground-water rights, and (2) seen increased legislative development of comprehensive ground-water management statutes that emphasize the reciprocal liabilities of ground-water use. These trends are examined and ground-water management programs discussed for eight states in the Midwest.     

Assessment Tools for Urban Catchments: Developing Biological Indicators Based on Benthic Macroinvertebrates1

Abstract: Biological indicators, particularly benthic macroinvertebrates, are widely used and effective measures of the impact of urbanization on stream ecosystems. A multimetric biological index of urbanization was developed using a large benthic macroinvertebrate dataset (n = 1,835) from the Baltimore, Maryland, metropolitan area and then validated with datasets from Cleveland, Ohio (n = 79); San Jose, California (n = 85); and a different subset of the Baltimore data (n = 85). The biological metrics used to develop the multimetric index were selected using several criteria and were required to represent ecological attributes of macroinvertebrate assemblages including taxonomic composition and richness (number of taxa in the insect orders of Ephemeroptera, Plecoptera, and Trichoptera), functional feeding group (number of taxa designated as filterers), and habit (percent of individuals which cling to the substrate). Quantile regression was used to select metrics and characterize the relationship between the final biological index and an urban gradient (composed of population density, road density, and urban land use). Although more complex biological indices exist, this simplified multimetric index showed a consistent relationship between biological indicators and urban conditions (as measured by quantile regression) in three climatic regions of the United States and can serve as an assessment tool for environmental managers to prioritize urban stream sites for restoration and protection.     

Total alkalinity of surface waters: a map of the upper midwest region of the United States

This map (see the inside back cover of this issue) illustrates the regional patterns of mean annual alkalinity of surface water in the northern portions of Minnesota, Wisconsin, and Michigan, USA. It provides a qualitative graphic overview of the relative potential sensitivity of surface waters to acidic input in the upper midwest portions of the United States. The map is based on data from approximately 14,000 lakes and streams and the apparent spatial associations between these data and macroscale watershed characteristics that are thought to affect alkalinity.For the map of the Upper Midwest Region of the United States, see the inside back cover of this issue.     

A targeting approach for ecosystem protection

The Critical Ecosystems Team of the US Environmental Protection Agency (EPA), Region 5, has developed an approach to prioritize and target ecologically high-quality areas for enhanced environmental protection in the Midwestern states of Illinois, Indiana, Ohio, Michigan, Minnesota and Wisconsin. Using this approach, we intend to employ a pro-active strategy to protect the environment by protecting and restoring natural ecosystems rather than the traditional EPA approach of remediating and attempting to restore already degraded habitats. The approach consists of two components: (1) partnership and (2) criteria. For the partnership component, we collected, mapped, and summarized information on ecosystems considered critical to federal and state agencies, tribes and non-profit organizations. Multi-county areas with high numbers of ecosystems identified by a variety of partners were designated as ‘Ecologically Rich Regions’. These Ecologically Rich Regions highlight broad geographic areas where there are high levels of partner interest and, correspondingly, areas with high potential for forming collaborative partnerships for enhanced environmental protection. The second component, which relies on criteria, is still under development and defines critical ecosystems as having three important properties: (1) high ecological diversity, (2) potential for long-term sustainability and (3) presence of relict native ecosystems or communities. The information compiled under both components of this ecosystem targeting approach will inform ecological risk managers and assessors about important ecosystems that should be considered in risk management and assessment processes.     

LONG-TERM VARIATIONS IN SEASONAL WEATHER CONDITIONS IMPORTANT TO WATER RESOURCES IN ILLINOIS1

ABSTRACT: An analysis of historical relationships between seasonal weather conditions and water resource conditions in Illinois provides insights to the challenges of projecting such relationships under conditions of climate change. In Illinois for 1901–1997 there were major temporal shifts in types of seasonal conditions that have positive and negative effects on surface water and ground water supplies and their quality. Major seasonal effects came in the spring and summer seasons and when either wet-and-warm or dry-and-warm weather conditions prevailed in either season. Sixty percent of the summer seasons creating negative impacts occurred during only 40 years: 1911–1940 and 1951–1960. Seasons creating impacts relate well to the frequency of cyclone passages and to the incidence of El Niño or La Niña conditions. This reveals that future climate fluctuations that shift the frequency of cyclones and/or ENSO events will have profound effects on Midwestern seasonal conditions that affect water resources. Projecting future effects of climate change on water resources will need to consider how shifts in water use and water management technologies act to re-define the seasonal weather conditions that are critical.     

THE EFFECTS OF CLIMATE CHANGE AND IRRIGATION ON CRITERION LOW STREAMFLOWS USED FOR DETERMINING TOTAL MAXIMUM DAILY LOADS1

ABSTRACT: This paper addresses the possible impacts of global climate change on low streamflows in the Midwest, both directly, through lower precipitation, and indirectly, by rendering irrigation profitable in areas where it has found little application in the past. In the analysis presented here, streamflow data are altered to represent the effect of climate change and stream-supplied irrigation, and then used to estimate new values for two low-flow criteria, the one- and seven-day-ten-year low flows (₇Q₁₀ and ₁Q₁₀) under 20 climate change and irrigation scenarios. Additionally, the frequencies of violation of these two criteria, and multiple violations in a three-year period, are determined. Results show that the potential impact of the assumed climate change scenarios on low flow standards is substantial. A 25 percent decrease in mean precipitation results in a 63 percent reduction in design flow, even in the absence of irrigation. With irrigation, the reduction can be as much as 100 percent. The frequency of single violations of low flow criteria is found to increase several fold with irrigation. The frequency of multiple violations of low flow criteria in a three-year period is sensitive to climate change, increasing from around 20 percent to nearly 100 percent as the climate change becomes more severe.