Foreword

Studies described in this report are based upon a research program, "Biodiversity and Landscape Planning: Alternative Futures for the Region of Camp Pendleton, California," which explored how urban growth and change in the rapidly developing area located between San Diego and Los Angeles might influence the biodiversity of the area. The research was conducted by a team of investigators from the Harvard University Graduate School of Design, Utah State University, the National Biological Service, the USDA Forest Service, The Nature Conservancy, and the Biodiversity Research Consortium. (Steinitz et al, 1996)

Recently, the U.S. Environmental Protection Agency’s Science Advisory Board identified habitat modification and loss of species as two factors which pose the highest level of environmental risk to the country. The intent of the research was to examine the connections among urban, suburban, and rural development and the consequent stresses on native habitats and biodiversity in a region that is one of the most biologically diverse in the continental United States.

The major product of the research is a computer-based Geographic Information System and a set of models which evaluate the complex dynamic processes of the very large study area and the possible impacts on biodiversity resulting from changes in land use. The soils models evaluate the agricultural productivity of the area's soils. The hydrology models predict the 25-year storm hydrographs for each of the rivers and their subwatersheds, flooding heights and water discharge, and resultant soil moisture. The fire models assess both the need for fire in maintaining vegetation habitat, and the risks of fire and fire suppression. The visual model assesses scenic preferences for the region’s landscape. Biodiversity is assessed in three ways: a landscape ecological pattern model; ten selected single species potential habitat models; and a species richness model.

A 1995 graduate-level studio at the Harvard Graduate School of Design applied the research framework in the design and comparison of the implications of six alternative regional conservation-development strategies for the study region. The 1996 studio had the challenging task of proposing a "best alternative design."

The studio was organized to answer six questions following the framework outlined by Carl Steinitz (1990), as was the research program which provided a context for this study. The framework as shown in Figure 1 identifies six different questions, each of which is related to a theory-driven model or answer. The framework is "passed through" at least three times in any project: first, downward in identifying the context and scope of the study–defining the questions; second, upward in specifying the methods of design–deciding how to answer the questions; and third, downward in carrying the design to its conclusion–providing the answers.

The six questions with their associated modeling types are listed in the order in which they are usually considered when initially defining a design study:

1. How should the state of the landscape be described; in content, boundaries, space, and time? This level of inquiry leads to Representation models.
2. How does the landscape operate? What are the functional and structural relationships among its elements? This level of inquiry leads to Process models.
3. Is the current landscape functioning well? The metrics of judgment–whether health, beauty, cost, nutrient flow, or user satisfaction–lead to Evaluation models.
4. How might the landscape be altered; by what actions where and when? This is directly related to the first modeling type, described above, in that both are data; vocabulary and syntax. This fourth level of inquiry leads to Change models. At least two important types of change should be considered: change by current projected trends, and change by implementable design, such as plans, investments, and regulations.
5. What predictable differences might the changes cause? This is directly related to II, above, in that both are based on information; on predictive theory. This fifth level of inquiry shapes Impact models, in which the process models (II) are used to simulate change.
6. Should the landscape be changed? How is a comparative evaluation among the impacts of alternative changes to be made? This is directly related to III, above, in that both are based on knowledge; on cultural values. This sixth level of inquiry leads to Decision models.

[Implementation should be considered another level, but this framework considers it as a forward-in-time feedback to Level I, the creation of a changed representation model.]

Note that the six levels have been presented in the order in which they are normally recognized. However, it is more important to consider them in reverse order as a more effective way of both organizing a landscape study and specifying its methods. The methods should be organized and specified upward through the levels of inquiry, with each level defining its necessary contributing products from the models next above in the framework.

VI. To be able to decide to make a change (or not) one needs to know how to compare alternatives.

V. To be able to compare alternatives, one needs to predict their impacts from having simulated changes.

IV. To be able to simulate change, one needs to specify (or design) the changes to be simulated.

III. To be able to specify potential changes (if any) one needs to evaluate the current conditions.

II. To be able to evaluate the landscape, one needs to understand how it works as processes; and

I. To understand how it works, one needs representational schema to describe it.

Then, in order to be effective and efficient, a landscape project should progress downward at least once through each level of inquiry, applying the appropriate modeling types:

1. Representation
2. Process
3. Evaluation
4. Change
5. Impact
6. Decision

At the extreme, two decisions present themselves: "no" and "yes." A "no" implies a backward feedback loop and the need to alter a prior level. All six levels can be the focus of feedback; (IV), "redesign", is a frequently applied feedback strategy. A "contingent yes" decision (still a "no") may also trigger a shift in the scale or size or time of the study. (An example is a highway corridor location decision made on the basis of a more detailed alignment analysis). In a scale shift, the study will again proceed through the six levels of the framework, as previously described.

A project should normally continue until it achieves a positive, "yes," decision. A "yes" decision implies implementation and (one assumes) a forward-in-time change to new representation models.

A long tradition of "top-down" decision-making characterizes the realm of physical planning and design. The tradition is reflected in the normal practice of considering scale-related decisions in a hierarchical manner: the larger, regional issues being considered first and the more local, "stakeholder-scale" aspects being considered last. There is also a history of the reverse, of "bottom-up" decision-making, in which the future of an area is considered as being the sum of the actions of its individual parts.

Neither of these approaches defined this study. Rather, four scales of design were investigated simultaneously, with each level cognizant of, and necessarily interacting with, the ones "above" and "below" and forward-in-time. At each scale, the previously described six-question framework was explicitly or implicitly the basis for structuring the design activities and for inter-scale discussion. The students working at each scale were also aware of the time dimensions of their realm of design. Thus, this study was the first to "test" the usefulness of the Steinitz framework in its changing-scale and changing-time modes (Figure 2).

Most interesting–both from a pedagogic and a professional perspective–is the differentiation among scale-dependent design studies in the languages in which design proposals and decisions were expressed.

The regional-scale design issues were expressed as larger conservation acquisitions and regional conservation-oriented regulatory approaches, and as major public capital infrastructure investments aimed at influencing urbanization patterns. As can be seen in the regional implementation strategy, these would be public actions.

The design issues at a sub-regional scale, such as those considered in the studies of the new City Center area of the Temecula Valley, tended to be expressed in the normal language of urban design: transportation patterns, major land use and zoning decisions, built-massing studies, and diagrammatic activity–relationships such as those among schools, recreation, and residential areas. These would reflect public policies and actions and guide private investment. This scale of design is illustrated in the proposed 2030 design for the Temecula Valley.

At the scale of a large site, where one major investor-stakeholder can control a multi-stage development, the language of design was that of site planning. It included road alignment, "in-scale" land use and building massing, as well as schematic design of major development and built-landscape elements. This site planning approach was applied in the studies of the five typical sites.

Finally, and at the scale of a typical individual stakeholder (for example, the builder of one house on one property), are the various site development guidelines. A study of this type does not yet involve the detailed design that is the common practice of architecture and landscape architecture. There is too much variation; furthermore, there is a potentially excessive infringement of individual judgment. Rather, the focus is on guidelines, which are expressed as diagrammatic "do" and "don’t" principles which reflect public influences on private actions. They shape a design-space within which private decision-making is dominant.

None of these scale-related modes of representation and design comes as a surprise. But what is notable is that at each scale the language of representation of the design is different: law, investment, infrastructure, conservation, zoning, massing, schematic design, guidelines, and exemplar cases. All of these are design languages, especially when acknowledging Herbert Simon’s definition: "Everyone designs who devises courses of action aimed at changing existing situations into preferred ones."

Another notable aspect of the study is its non-hierarchical approach across the several scales of design. Each inter-scale negotiation (and there were many) involved at least two representational languages for the same content-issue. And many of these discussions "jumped" scales. Many were discussions with parallel interests. However, many more were directed at resolving conflicts; at one scale the decision may favor conservation, but the same geography, seen through the lens of a different scale, may favor development. Observation of these many negotiations revealed a dominant (but not universal) pattern of resolution. In general, decisions in which "demand issues" were dominant tended to be resolved in favor of the larger area (smaller scale) over the smaller area (more detailed, larger scale). Examples include the location of a needed road, the location of water storage capacity, the area required for institutions or industry. However, situations in which "supply issues" were crucial tended to favor the more detailed over the more general. Examples are the conservation of habitat for the California gnatcatcher and other rare and endangered species, wetlands, historic places, and steep slopes. The more spatially detailed guidelines had a major influence on the regional conservation strategy.

In this study, neither the more commonplace "top-down" or "bottom-up" design approaches would have been as effective as this more complex, interactive one. For stakeholders and designers working to improve the "larger landscape," perhaps this is one of the most important lessons to be derived from the study.