Infrastructure construction and

maintenance are critical to a community’s sustainability and vitality.

Rapid population growth has resulted

in inadequate infrastructures in

communities in many areas of the

country. Building and maintaining

the infrastructure, such as roads and

buildings, require large volumes of

three natural resources: aggregate

(primarily crushed stone, sand, and

gravel), water, and energy. As urban

areas expand, local sources for these

resources become depleted, inaccessible, and more costly to recover.

Because of exploding population

growth, the Denver metropolitan area

must now deal with conflicting

claims between urbanization and

preserving the natural resources

needed to sustain urbanization (fig. 1). 

Background

Between 1991 and 1997, Colorado

became the Nation’s fifth fastest

growing state. Most of the new

growth occurred along the Front

Range, from the eastern foothills of

the Rocky Mountains to the shortgrass prairies of the high plains,

called the Colorado Piedmont. The

U.S. Geological Survey’s (USGS)

Front Range Infrastructure Resources

project (FRIRP) is generating information on the natural resources

critical for the infrastructure needed

by growing urban areas and developing methodology to help in the

planning process. Land characterization models will help both the 

technical and nontechnical person

understand the nature of the land and

make informed decisions and

assessments. The project, which

began October 1, 1996, is focused on

a demonstration area in the northern

Colorado Front Range urban corridor.

The demonstration area includes

most of the Denver metropolitan area

and the rapidly growing areas to the

north in western Adams County,

eastern Boulder County, southeastern

Larimer County, and southwestern

Weld County. Subsequent studies will

expand the area to the entire Rocky

Mountain Front Range urban corridor

(from Cheyenne, Wyoming, to

Pueblo, Colorado). 

A dichotomy does not exist between

the physical and human environment; 

they must be studied together.

Humans have no control over the 

occurrence of resources; often the

occurrence of a single resource rather

than a diversity of resources affects

the development of urban areas. The

Denver metropolitan area developed

because of one important resource —

gold. Agriculture developed as a

response to the increasing populations of gold seekers. The development of the agriculture patterns (large

cooperatives to build irrigation

canals) developed as a response to

the physical environment (good soils

needing irrigation). Understanding

the interrelationship of the landscape

with human activity, how it has

changed (fig. 2), and how it might

continue to change is important in the

urban environment, for it is in the

urban environment that humans’

impacts on the physical environment

are most evident. 

U.S. Department of the Interior

U.S. Geological Survey USGSFact Sheet 127-98

October 1998

Figure 1. Suburban expansion results in competing use of the land (agriculture and gravel extraction).

Front Range Infrastructure Resources Project

Land Characterization Activities
Critical Landscape

Characteristic Components

The USGS, along with local entities,

is identifying those critical components that define the landscape along

the Front Range. The physical

characteristics of the earth, air, water,

and ecology intermingle with human

settlement patterns of yesterday and

today. The causes, timing, types,

impacts, and extent of change vary

from place to place. Local changes in

land use can have effects that ripple

throughout a larger region. The

combination of local and Federal data

resources will enable the project to

yield credible and comprehensive

insights into the character and

impacts of land use change, insights

that can contribute to plans for

creating a balance between urban

growth and environmental protection.

Understanding how and why an

urban area has developed can aid in

understanding how the region may

continue to grow. A temporally

consistent database is essential for

the project. Existing geographic

features over the study area range in

age from the 1950’s to the 1990’s. A

revision of these features is necessary

to model the current conditions in the

area. The temporal database resulting

from this project will document the

urban land transformation (fig 3).

The database can be used by urban

and regional planners, policy and

decision makers, and earth scientists

to measure trends in urban sprawl,

analyze patterns of water pollution

and sedimentation, understand how

development affects ecosystems, and

develop predictive modeling

techniques to better forecast future

areas of urban growth. 

A geographic information system

(GIS) will integrate the data

generated by the project. A

temporally consistent reference for

all the project data is provided by the

base cartographic data layers. By

combining the physical

characteristics of the land with the

human settlement patterns, we can

achieve a more accurate and

comprehensive depiction of the

landscape, which can help

communities make decisions

regarding growth and its impacts. 

The database framework will include

the following:

Base Cartographic Data Layers

• transportation networks 

• surface hydrography

• administrative boundaries 

• elevation

• manmade structures

• township, range, and section lines

(Public Land Survey System)

Physical Characteristics of the Land:

• soils

• engineering properties of the

geologic structure

• ground-water availability

• depth to water table 

• water table thickness

• aggregate (sand and gravel)

availability and quality

• oil and gas quantity and quality

• environmental impacts of oil and

gas production

• locations of abandoned coal mines

and depth of coal mines

• vegetation communities

• species communities 

• rankings of slope

Figure 2. Aerial photos of Golden from 1930 to 1990. Understanding urban trends with a temporal database facilitates

decision-making processes.

Golden—1930 Golden—1950

Golden—1970 Golden—1990
Human Induced Characteristics of the

Land:

• 1930’s land use and land cover data

• 1950’s land use and land cover data

• 1970’s land use and land cover data

• 1990’s land use and land cover data

• urban growth scenarios

• population demographics,

including:

number of potential new jobs

number of school-aged children

effects on current transportation

networks

Land cover data contain information

about what is on the surface of the

land (for example, deciduous forest).

In the urban environment, what is on

the surface of the land is captured in

terms of how the land is being used

(for example, single family

residential). 

Group Spatial Decision Support

System

Decisions regarding land and natural

resources are often complex and

emotionally charged. Different

parties often have varied interpretations of a proposed change. As part

of the FRIRP project, the USGS is

developing a Group Spatial Decision

Support System (GSDSS) (fig. 4). A

GSDSS is a software package that

combines the natural resource information obtained from the FRIRP

with socioeconomic information

obtained from a local entity, such as

the Denver Regional Council of

Governments, to aid planning

agencies in making land use

decisions. For example, if a proposal

to put in a new subdivision were

under review, planners might view

species habitats, geology, soils, water,

and energy information plus socioeconomic information, such as

number of potential new jobs,

impacts on current transportation

networks, and increase in the number

of school-aged children. Using the

GSDSS, planners will be able to

create different scenarios and easily

see how each one may create varying

levels of impact on an area; they will 

then make decisions that are based on

the impacts of implementing a

proposed change.

Information

For more information on the project

visit our web site at:

http://webserver.cr.usgs.gov/frirp/

FRIRP.html.

Urban Extent 1930’s Urban Extent 1950’s

Urban Extent 1970’s Urban Extent 1990’s

Major transportation

EXPLANATION

Urban Classes

Urban/built-up

Non-urban

Water

Figure 3. Visualizing urban growth through time. Commerce City, Colo.
For more information on the

individual aspects of the project

contact any of the following:

Geographic Resources:

Carol Mladinich

Phone: 303-202-4313

E-mail: csmladinich@usgs.gov

Group Spatial Decision Support

System:

Richard Zirbes

Phone: 303-202-4303

E-mail: rjzirbes@usgs.gov

For information on other USGS

products and services, call 1-800-

USA-MAPS, use the EARTHFAX

fax-on-demand system, which is

available 24 hours a day at

703-648-4888, or visit the general

interest publications Web site at

http://mapping.usgs.gov/

www/products/mappubs.html.

Please visit the USGS home page at

http://www.usgs.gov/. Figure 4. GSDSS brings together natural resource and socioeconomic information to aid planning agencies in making land

use decisions.