Chapter 18: Integration Methods for Environmental Land Use Analysis

Discussion Questions
Exercises
Links

Summary
Previous chapters presented a wide range of techniques used to gather and analyze environmental information for use in planning and management. Rarely are these methods used alone. More often, planners, publics, and decision makers need to make sense of the results of these analyses and to integrate them into comprehensive or holistic assessments.

The methods presented in this chapter aim to provide this integration. The environmental inventory simply assembles spatial data in an understandable form, without analysis, so the user can make his or her own conclusions. Rapid assessment aims to gather and interpret information quickly as a basis for immediate action or to identify needs for intermediate or advanced assessment. Land suitability analysis takes baseline information further, combining sometimes diverse spatial data to assess the land’s intrinsic capability for different uses. It can be used to screen sites for a particular use, gauge vulnerability of sensitive areas for certain uses, evaluate development pressure, and develop comprehensive land use plans.

Carrying capacity is an ecological concept originally used for wildlife and range management. It has had considerable appeal for managing human settlements but proved ineffective when used to estimate appropriate population levels. When applied to the impacts of population growth, however, the concept became more useful. Instead of an optimal level of population, this approach sets acceptable levels of thresholds of impact measured by indicators of change or condition in selected environmental and socioeconomic attributes. The "impact threshold" approach to carrying capacity has been used effectively in managing development in the Lake Tahoe Basin and in managing visitor use in wilderness areas.

Environmental impact assessment is one of the most used environmental analysis methods in the world. Despite its limitations, EIA has been a consistent source of environmental information for federal decision making. Its use in community land use and development is limited, but states like Washington and California, which use EIA routinely in local land use and development planning and decisions, have proven its potential value. EIA needs to occur early in the development process to be effective.

Build-out analysis is simply EIA for land use plans and zoning ordinances. It assumes a site or community will realize the full density of development permitted by ordinance and builds it out. When shown in map form along with impact analyses, the visual image of a community’s future by right as well as assessment of its environmental and community impacts, can spur planners, citizens, and elected officials to question existing plans and seek more environmentally compatible alternatives. Massachusetts has employed build-out analysis through GIS as a key element of its community preservation planning program.

Chapter 18 Discussion Questions

1. What is an environmental inventory? Give three of its uses in environmental land analysis and land use planning.

2. Land Evaluation and Site Assessment (LESA) for agricultural lands, Land Suitability Analysis, and DRASTIC for groundwater contamination potential have become three well accepted methods for environmental land analysis at the county level. All use the sum-of-weighted-factors method. Besides the fact that they are applied for different purposes, what are two basic differences in the methods?

3. Build-Out Analysis has become a useful analytical tool for assessing plans and regulations.
a. Briefly describe Build-Out Analysis:
b. How is it similar to environmental impact assessment?
c. How can it be used in comprehensive planning and revising zoning ordinances?

Chapter 18 Exercises:

1. You have been asked to revise a town development plan. The Figure from Griggs and Gilchrist (1983) gives the existing development of the town (a) and a preliminary plan (b). Local citizens have revolted against the plan and demanded a revision based on the environmental information of map (c). On a separate sheet of paper, draw up a revised land use plan which takes into account the environmental information but which allows for about the same number of development units as the preliminary plan. You may use different densities than those given in map (b). Briefly explain your proposal.

2. You are a newly-hired as a local planner on a barrier island community where a high school biology teacher is serving his first term on the Town Council. He is a no-growth advocate, and has been pushing the "carrying capacity" concept to limit population of the island. Basically, his argument is that there is a natural carrying capacity of the island to support a given number of people and that once that capacity is reached, there should be no more building permits approved. The full Town Council has asked the Planning Director, and he has asked you, to prepare a one-page memo discussing the positive and negative aspects of his argument. The Council is fully aware of the property rights implications of his recommendations and wants you to address the scientific basis for his case.

3. An environmental inventory and community participation process has revealed the following important environmental concerns in a local jurisdictional. You have been asked to suggest two options that could be used by local government or local groups to manage each of these concerns.
a. flood prone area:
b. locally desirable wildlife habitat:
c. productive agricultural land that is important to the character of the community:
d. karst terrain and sinkholes:
e. a viewshed of particular importance to the character and aesthetic of the community:
f. unique vegetative habitat that supports a variety of desirable wildlife species:
c. karst terrain and sinkholes that pose a threat to groudwater:
-Where would you look for spatial information on the following environmental factors. Indicate what analysis of the information, if any, in needed.
• Highly erodible lands:
Source(s) of information?
What analysis needed?
• Flood prone areas:
Source(s) of information?
What analysis needed?
• Recent development (last 2 years):
Source(s) of information?
What analysis needed?
• Unstable slopes:
Source(s) of information?
What analysis needed?
• Prime agricultural lands:
Source(s) of information?
What analysis needed?

Comprehensive questions:
1. Much of this class has dealt with scientific concepts and technical analysis of environmental land resources. This information is essential for land use decisions that integrate environmental factors. But most land use decisions in the U.S. still rest on political and economic grounds. However, we are seeing new approaches to land use decisionmaking in applications such as watershed management, ecosystem management, habitat conservation planning, urban forestry, brownfields redevelopment, and "collaborative" development. These approaches integrate science and politics and aim to broaden the range of values and participants in the decision process in an effort to achieve better land use decisions.
Briefly, characterize three of the main elements that these approaches have in common and comment on their potential effectiveness.
Main Elements:
Comments on effectiveness:
2. In a few words, convince me that you know what these mean:
Frontier Economics:
Consistence:
Sustainable Development:
Semi-confined aquifer:
Subsidence:
Unified Classification System:
Piezometric Surface:
Rational Method:
Creep:
"Jurisdictional" wetland:
Ecotone:
"Sewer Power":
Littoral drift:
Concurrency:
Edge effect:
Sliding-scale zoning:
Incidental Take:
Orthophotoquad:
Ecodevelopment:
Scoping:
Level Spreader:
Oblique Photo:
Lag time:
Plasticity:
Bioretention:
Ecotone:
Incidental Take:
"Gestalt" Land Suitability:
Drainage Density:
Curve Number:
Green Infrastructure:
Phased Development System:
3. In a few words, convince me that you know the difference between the following:
a. Raster System....Vector System
b. Environmental Inventory….Land Suitability Analysis
c. Habitat Conservation Plan….Natural Community Conservation Plan
d. Linear Combination....Ordinal Combination
e. Purchase of Development Rights....Conservation Easement
f. Density Transfer....Density Bonus
g. Partial Evaluation Technique….Comprehensive Evaluation Technique
h. Rational Comprehensive Planning…Incremental Planning
i. Transfer of Development Rights…Purchase of Development Rights
j. Brownfields…Grayfields