2024年3月31日发(作者：)

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INVENTORY AND ANALYSIS OF THE BIOPHYSICAL ENVIRONMENT

After a community has identified the challenges and

opportunities that it faces and has reached some

consensus concerning its goals to address those issues,

then it is necessary to collect the information needed to

achieve community goals. An inventory is a systematic

acquisition of information needed to describe and

characterize a place. Inventories provide the basis for

ecological analysis. Information about nature has often

been used in an AD HOC manner in American planning.

Only that information needed to achieve a specific goal

is collected—so too often it is disconnected

information.

The basic premise of ecology is that everything is

connected to everything else. As a result, the ecological

approach differs from more traditional methods. For

example, a flood frequently prompts community

interests in planning, especially when loss of life and

property damage has occurred. With a conventional

planning response, only the flood-prone areas are

identified. Also, this approach focuses primarily on the

negative consequences of flooding. Since flooding is

recognized by a community as a hazard to human safety,

the responsible elected officials adopt a goal to prevent

buildings in flood-prone areas. These areas are mapped

and building restricted. The goal is one-dimensional. In

contrast, in ecological planning the complex matrix of

factors related to flooding would be considered.

Flooding is the result of the interaction

of several natural phenomena—rainfall, bedrock,

terrain, soils, temperature, and vegetation, for instance.

Since ecological planning rests on an understanding of

relationships, broader-range information about the

biophysical processes of an area must be collected and

analyzed. In addition, an ecological view acknowledges

the benefits of natural flooding events, such as the

deposition of fertile soils. Moreover, the sequence of

collecting this information becomes important.

Older, larger-scale components of the landscape exert

a strong influence on more ephemeral elements.

Regional climate and geology help to determine soils

and water drainage systems of an area, which in turn

affect what vegetation and animals will inhabit a place.

The challenge for the ecological planner is to think

geologically in both space and time. One must think big,

because it is likely that the geologic events that occur in

a specific planning area or jurisdiction are probably

driven by plate tectonic interactions thousands of

kilometers away, and climatic events by processes

working on a global scale. The temporal scale is also

quite large, with the human time scale so much shorter

than that of the geologic events within a planning area.

As a result, in ecological planning one begins to

inventory the older elements and proceeds to the

youngest. The systematic survey of information should

lead to an understanding of processes, not merely the

collection of Data.

When conducting such an inventory, it is useful to

identify boundaries so that the various biophysical

elements can be compared with each other over the

same spatial area and at the same scale. Often such a

planning area is defined by legislative goals, as, for

instance, with the New Jersey Pinelands. Ideally,

several levels of inventories from regional to local are

undertaken. As Richard Forman has advised, we should

“think globally, plan regionally, and act locally” (1995,

435). A hierarchy of levels is identified so that the

planning area may be understood as part of a larger

system and specific places may be seen as parts of a

whole. The large river drainage basin at the regional

level and the smaller stream watershed more locally are

ideal units of analysis for ecological planning. A

watershed is an area drained by a stream or stream

system, also called a catchment area or, in the United

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States at a larger river scale, including all the tributaries,

a drainage basin.

A drainage basin, or watershed, “is the area of land

that drains water, sediment, and dissolved materials to a

common outlet at some point along a stream channel”

use of watersheds is also consistent with past efforts of

watershed conservancies and river basin commissions,

such as the Delaware River Basin Commission, the

Columbia River Basin Commission, and the Tennessee

Valley Authority, and with programs of the Natural

(Dunne and Leopold 1978, 495). According to Donald

Satterlund and Paul Adams (1992, 51), “A watershed is

defined by the stream that drains it.” The drainageway,

meanwhile, “refers to the principal areas of water

accumulation (i.e., channels)” (Briggs 1996, 17).

A watershed, or other landscape, may be understood

through a chorography—in other words, a systematic

description and analysis. Ecology can be used to order

such a chorography since ecology addresses

interrelationships among living things and their

environments. The ecologist Eugene Odum has

observed the value of using watersheds in planning.

Odum noted that “it is the whole drainage basin, not

just the body of water, that must be considered as the

minimum ecosystem unit when it comes to man’s

interests. The ecosystem unit for practical management

must then include for every square meter or acre of

water at least 20 times an area of terrestrial watershed”

(Odum 1971, 16).

Peter Quinby (1988) notes that watershed boundaries

can be used as ecosystem boundaries. The watershed is

a handy unit that contains biological, physical, social,

and economic processes. Watersheds have discrete

boundaries, yet they can vary in scale. This provides

flexibility to adapt to social, economic, and political

issues. Watersheds also offer linkages between the

elements of regions. One reason they can be considered

an ideal is that the flow of water, the linkage,

throughout the watershed may be easily visualized.

The use of watersheds for planning is not new.

John Wesley Powell, who introduced the term region to

North America, essentially suggested the use of

watersheds in his 1879 plan for the American West. The

Resources Conservation Service, the Army Corps of

Engineers, the National Park Service, and the U.S.

Forest Service. But, more often than not, units other

than watersheds— political boundaries most

frequently—are used. Still the principle of hierarchy

can apply to political boundaries, with counties forming

the regional scale and cities or towns being used as the

unit for local landscape analysis.

In this chapter, a method for the inventory, analysis,

and synthesis of the biophysical components of the

landscape in the planning process is presented. This

approach to data collection can be used at the regional,

local, and even site-specific scales. To illustrate this

chapter, an example of the Desert View Tri-Villages

Area of Phoenix, Arizona, is used. This landscape was

formerly named “Planning Areas C & D” by city

officials. This biophysical inventory and analysis was

conducted as a part of a larger city planning process.

The area encompasses approximately 20 percent of the

city and was largely undeveloped when ecological

inventories were initiated. Two slightly different

boundaries appear in the examples that follow because

they were drawn from different inventories conducted

in the space of three years (Ciekot et al. 1995; Brady et

al. 1998). In the intervening years, the city of Phoenix

annexed more land, changing the study area boundaries.

This chapter presents methods for making base maps,

inventorying elements of the landscape, and analyzing

and synthesizing this information. Two examples, the

New Jersey Pinelands and the region of Camp

Pendleton, California, are also used as illustrations.

Each example employed an approach similar to the one