Ecological Planning Method - Design with the Desert: Conservation and Sustainable Development - page 238

TABLE 13.1
Baseline Natural Resources
Data Necessary for Ecological Planning
The following natural resource factors are likely to be of significance in planning. Clearly the region
under study will determine the relevant factors, but many are likely to occur in all studies
Climate. Temperature, humidity, precipitation, wind velocity, wind direction, wind duration, first and
last frosts, snow, frost, fog, inversions, hurricanes, tornadoes, tsunamis, typhoons, Chinook winds
Geology. Rocks, ages, formations, plans, sections, properties, seismic activity, earthquakes, rock slides,
mud slides, subsidence
Surficial Geology. Kames, kettles, eskers, moraines, drift and till
Groundwater Hydrology. Geological formations interpreted as aquifers with well locations, well logs,
water quantity and quality, water table
Physiography. Physiographic regions, subregions, features, contours, sections, slopes, aspect,
insolation, digital terrain model(s)
Surficial Hydrology. Oceans, lakes, deltas, rivers, streams, creeks, marshes, swamps, wetlands, stream
orders, density, discharges, gauges, water quality, floodplains
Soils. Soil associations, soil series, properties, depth to seasonal high water table, depth to bedrock,
shrink-swell, compressive strength, cation and anion exchange, acidity-alkalinity
Vegetation. Associations, communities, species, composition, distribution, age and conditions, visual
quality, species number, rare and endangered species, fire history, successional history
Wildlife. Habitats, animal populations, census data, rare and endangered species, scientific and
educational value
Human. Ethnographic history, settlement patterns, existing land use, existing infrastructure, economic
activities, population characteristics
between human values, environmental opportunities and constraints, and the issues
being addressed. To accomplish this, it is crucial to link the studies to the local situation.
As a result, a variety of scales may be used to explore linkages.
A simplified suitability analysis process is provided in Figure 13.3. There are several
techniques that may be used to accomplish suitability analysis. Again, it was McHarg
who popularized the “overlay technique.” 42 This technique involves maps of inventory
information superimposed on one another to identify areas that provide, first, oppor-
tunities for particular land uses and, second, constraints. 43 MacDougall 44 has criticized
the accuracy of map overlays and made suggestions on how map overlays may be made
more accurate.
Although there has been a general tendency away from hand-drawn overlays, there
are still occasions when they may be useful. For instance, they may be helpful for small
study sites within a larger region or for certain scales of project planning. It is important
to realize the limitations of hand-drawn overlays. As an example, after more than three
or four overlays, they may become opaque; there are the accuracy questions raised by
MacDougall 44 and others that are especially acute with hand-drawn maps; and there are
limitations for weighting various values represented by map units. Computer technology
may help to overcome these limitations.
Numerous computer program systems, called geographic information systems (GIS),
have been developed that replace the technique of hand-drawn overlays. Some of these
programs are intended to model only positions of environmental processes or phenomena,
while others are designed as comprehensive information storage, retrieval, and evaluation
systems. These systems are intended to improve efficiency and economy in information
handling, especially for large or complex planning projects.