Land Use: Decisions, Development, Management

Wise land use in the central Great Lakes states depends on a practical working knowledge of glacial geology: the thick deposits of sand, gravel, silt, and clay that blanket the region's bedrock.

Information Gap

Detailed surficial geology maps are essential today to make sensible development decisions regarding water and mineral resources, environmental protection, and geologic-hazard reduction. Yet only a very small part of the region's surficial geology is mapped in sufficient detail to support truly informed decisions. Timely production of this geologic information requires resources and capabilities beyond those available to any one state, so the State Geological Surveys of Illinois, Indiana, Michigan, and Ohio have joined with the U.S. Geological Survey to form the Central Great Lakes Geologic Mapping Coalition.

Only through collaborative efforts between the four states and the federal government can the enormous scope of this need be realistically addressed. This coalition of the geologic surveys will serve as a model for state/federal cooperation to provide interstate geological information needed for the 21st century.

Geologic Problems Don't Stop at State Lines

The coalition was formed because our states' common geology produces common geological problems. The coalition allows us to pool our resources to address these common resource and environmental problems. The coalition agreement allows for sharing of resources, such as equipment and laboratories, but most importantly, the coalition pools the broad and various experiences and expertise of the scientists in all five agencies. When it comes to projects of this magnitude, the whole is greater than the sum of the parts, as cooperative working relationships produce better and faster results.

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Mapping for Smart Growth in the 21st Century

When developers, industrial and mining interests, environmental groups, conservationists naturalists, communities, and private citizens compete for land, water, and biological resources, conflicting and complex options often result.

It is a difficult task for local and state decision-makers to support urban/suburban development while also ensuring access to the water and mineral resources needed by growing and shifting populations. It becomes even more difficult when they are faced with the need to manage the environment in a non-destructive and sustainable manner, and assess and avoid hazards and risks to human life and property.

Conflicting demands on resources and inadequate information about their nature and three-dimensional distribution have resulted in land-use decisions that we now see as incompatible with sustainable development in the region. Decisions made without an adequate base of earth-science information often increase the costs and risks to society and the environment. And they can compromise the quality of life of future generations.

Geological Information is used by

• County and city planners
• Water and other utilities
• Public health agencies
• State and county transportation departments
• Federal and state environment protection agencies
• Builders and developers
• Agricultural agencies
• Insurance companies
• U.S. Army Corps of Engineers
• Mining companies
• Environmental consultants
• Engineering firms

  Geologic Mapping Today

• Three-dimensional
• Computer-based
• User-friendly
  

  New geologic mapping techniques produce detailed, three-dimensional maps packed with information on:

• Materials Materials from soils to bedrock
• Resources Resources from water to construction aggregates
• Processes Processes from erosion to earthquakes
• Systems Systems from natural to managed watersheds

  The computer-based maps and models used by researchers at the five geological surveys help the scientists understand and interpret the data, and greatly improve access to the information necessary for decision-making.

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Wise Land-Use Policy & the, Need for Geologic Mapping

Less than 20/a of the region is geologically mapped in sufficient three-dimensional detail to support truly informed decisions on land use, water resource development and protection, and other critical issues.

Existing maps, which generally show only what is at the surface, simply don't have adequate information to resolve most current management issues.

Illinois, Indiana, Michigan, and Ohio share the common geological heritage of the Great Ice Age, and the complexity of the materials deposited by the great glaciers presents these states with a shared set of unique and common challenges. No single state can address these challenges alone. They require the cooperation and collaboration of the geological surveys of the four states and the U. S. Geological Survey.

Geologic Mapping for Resource Development

Much of the region's economy and well-being is based on the riches supplied by the deposits, or drift, left by the glaciers. Soil, water, and minerals, the resources that nurture all life and sustain our society, are the legacy of these glaciers:

• The region's rich soils developed on glacial deposits, including windblown silt.
• More than 500/o of our drinking water is pumped from buried sand and gravel aquifers formed by glacial meltwater streams.
• An important source of aggregate materials, essential to every building and road project, are sands and gravels.

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  Mapping for Geologic Safe & Healthy Environments

Detailed mapping of glacial deposits is critical to preserving a safe and healthy environment for ourselves and our children. As citizens of the region, we face many crucial health and environmental issues. All these issues involve landscapes composed of glacial deposits:

• keeping our underground drinking water, and rivers, streams, and lakes free of contamination
• protecting against floods, earthquakes, and soil and lakeshore erosion.
• safe siting of landfills, agri-chemical facilities, and hazardous waste disposal facilities
• reclaiming Land contaminated by previous generations
• maintaining and restoring natural areas and wetlands for hunting, fishing, boating, and recreation.

Glacial Geology Fascinating Complexity

Beneath the prairies, rolling hills, and waters of the central Great Lakes states lies a complex of many different layers of ancient soils, river deposits, and glacial deposits, all resting on the bedrock of the pre-glacial landscape and all buried beneath the deposits of younger glaciers.

Varying layers of sand and gravel, pebbly clay, and silt, which range in thickness from inches to more than 1,000 feet, were deposited by glaciers that repeatedly advanced out of Canada and retreated across the region over the last 1.5 million years. These materials are the foundation of our rich agricultural soils.

The complexity can only be glimpsed in the large map at left, which illustrates the basic outlines and thicknesses of glacial deposits. At the local level, and viewed in three dimensions, the picture becomes far more complex.

3-D Mapping

Glacial deposits are thick, extensive and complex. Even where adequate mapping information exists, it often is not available in modern electronic formats that allow ready access. Nor can other critical decision-supporting information, such as land use and demographic data, be easily combined with it.

Today, information provided by the scientific community to private and public users must be readily understandable and supplied in modem digitally downloadable and user-friendly forms.

The new digital mapping methods facilitate the production of derivative maps for a specific purpose.

The computer-generated two-dimensional map above is derived from mapping information that has been combined with other data to illustrate aquifer sensitivity to potential nitrate contamination; the orange areas are most vulnerable.

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