Methodology for Ecologically Based Landscape Planning
Some of the earliest environmental legislation passed by the U.S. federal and state governments in the early 1970’s provided an unprecedented opportunity to be on the ground floor of what today is called sustainable landscape design. As a regional planner for Tompkins County, New York, I was assigned with my colleague, Dr. Garrison Evans, to present patterns for the sound utilization of land in the county, part of the Comprehensive Plan program. The analytical procedure and document was called Environmental Image.
The New York State Development Plan had identified the Ithaca Urban Area as a node of continuing modest growth. Likewise, the Department of Transportation designated Tompkins County as one of the state's economic growth areas. These designations instigated active regional planning in the county, 490 square miles in area.
The purpose of the program was to inform citizens and municipal bodies of Tompkins County about the complex relationship between the natural and human-modified environment, so that decisions about development in the County could properly reflect the opportunities and constraints provided by the physical environment. The document presented basic information about the natural environment’s influence on development, and the impact of development on the natural environment. Ecologically sound development was interpreted to mean ‘avoid needless disruption of ecosystems, and balance the value of long-term development with the entire cost to society’.
There are fundamental reasons for ecologically based land use planning: 1) It reflects the benefits of directing future development to areas where expected impact on the total ecosystem is most favourable and least destructive. 2) An ecologically based evaluation of the natural environment helps determine the capacity of the land to accommodate human activities and facilities. 3) A systemic evaluation of utility and other public service facilities determines where urban-density expansion within and around existing settlements is considered best to occur.
This approach undermines outdated, unscientific, unsupportable, and potentially dangerous erroneous assumptions – the society of people is separate from the society of nature; people and nature are adversaries; and nature must be subdued. Scientific knowledge suggest the following operating ecological principles, regardless of human presence:
1) Everything affects everything else. All development has a measurable impact on the ecosystem.
2) All living things are component parts of physical environment systems.
3) Each system has the ability to expand or limit reproduction, growth and cessation of species.
4) Each system has a definable capacity to carry the organisms of the system.
5) Materials continually are recycled and reused in these systems.
6) All systems tend towards steady-state equilibrium.
Neglecting or overlooking these principles can precipitate ecological crises of varying magnitude; negative impacts are not inescapable. An embrace of ecological awareness and reliance on ecological science in the past had the potential to make significant differences in the quality of the present environment, we’re witnessing that a lack of environmental considerations has posed serious problems with which the global community now must deal.
Reason suggests things can be turned around and future development need not necessarily be negative. From a land use perspective, sound practices of environmental analysis recognize that particular areas are better suited for development than others. Future infrastructure for expected population growth can be developed so that the net impact on the environment tends to the positive or neutral. Harmonious development in areas considered ecologically suitable affords lower personal and social cost; however, it’s possible to build destructively even in the most suitable areas. Developing harmoniously with the natural environment benefits both the natural and human society.
There are areas where natural characteristics are unfavourable, posing the types of constraints that classify a site as unsuitable for development – in areas with shallow bedrock, high water table, poor drainage, soils highly subject to frost heaving, severe erosion susceptibility and steep slopes. It’s prudent to avoid these areas; expensive precautions to avoid or overcome formidable natural environmental constraints at huge expense best be expected.
Private and Social Cost
Justifying environmental precautions is a matter of private and public interest, subject to public scrutiny. Development is not a simple matter of assuming one has the right to use private property in any way one wishes. Environmental regulations restricting what can or can’t be done with private property are not simply private affairs; it can’t be assumed that costs are borne solely by individual stakeholders. In the larger arena, development benefits and costs are distributed to society as a whole; and opportunities lost for both private and social costs must be recognized.
In areas where personal and social costs to overcome environmental constraints is prohibitive, absolute prohibition to development may be justified. However, restrictions on developing these lands and waters may not be legally or politically supportable, even if contrary to ecologically and economically sound common sense. Municipalities would best hesitate to provide construction and maintenance for supporting infrastructure, providing public facilities and services, and for transporting persons, goods, and services.
Social cost is not a short-term issue. Because the ecosystem responds to impacts from modifying land, water and atmosphere of local and regional ecosystems in an evolutionary fashion, an ecologically based approach to landscape analysis and planning is to be viewed in the longest time frame possible.
Methodology and Environmental Factors Used for Ecologically Sound Land Use Planning
The purpose of the Environmental Image project was to define and delineate the most suitable areas in Tompkins County for urban and rural habitation by compiling and analyzing an exhaustive list of environmental factors. Prime references were The Ecological Basis for Land Use Planning by G. Angus Hills and Design with Nature by Ian McHarg.
Techniques for gathering and recording information – aerial photography rather than Google Earth, hand-drawn field work rather than GPS, hand-prepared Press-Type rather than computer-generated shading patterns – offered accurate analysis and synthesis of information.
Recognizing the operations of dynamic interactive relationships among environmental factors suggested that a mere listing of information threatened the task with over-simplification. To conceive an assessment as complete and comprehensive as possible, the list of environmental factors was divided into natural and human-induced components. The natural component was subdivided into fields of natural studies: geology, physiology, pedology, hydrology, flora and fauna. The human-induced component was subdivided into tangible factors directly encouraging or limiting private settlement.
A map was made for each physical and human-induced factor describing the operation, dimension, and quality or quantity of factor characteristics. Each map was delineated with press-on acetate sheets cut by hand with shading variations to indicate relative presence or severity of the factor characteristics.
Once environmental factors were collected, recorded, characterized and mapped, two analytical components were used: 1) Physical Compatibility, showing the ability of lands and waters to support settlement with accrued social benefits while imposing relatively fewer social costs; 2) Situation Suitability, describing direct and tangible human-induced activities that support settlement with accrued social benefits while imposing relatively fewer social costs.
Physical compatibility recognized: 1) environmental conditions that directly influence structural and utility system integrity and costs; 2) environmental conditions that require conservation management practices that add to overall suitability and reduce long-term personal and social costs; 3) fragile natural resources not necessarily compatible with settlement patterns; and 4) the suitability of land for agriculture.
Situation Suitability recognized: 1) land uses limiting private settlement, such as viable agricultural land and lands under preemptive activity and control such as publicly and university-owned lands; 2) historic and cultural resources; 3) improved-access and travel time; 4) and public utility systems.
Transparent maps of relevant environmental factors were overlaid on a backlit table. The availability of standard maps with a 1 inch = 1 mile scale (Soil Conservation Survey Associations Maps being accurate to 25 acres) governed the choice and accuracy of maps used. A visually distinct outline of composite factors geographically summarized the influence of each group of factors. If the importance or significance of one map or factor relative to another posed difficulty with this methodology, we sought assistance from experts in the appropriate field of resource analysis.
The immediate result of this ecologically based landscape planning procedure was the delineation of three types of areas of the county: areas considered most suitable, areas requiring modification at extensive cost, and areas considered unsuitable because of legal restrictions or prohibitive cost both for rural and urban density. The long-term result was the provision of effective development patterns more sympathetic to the operations of nature, as relevant today as it was in 1975.