GIS for Holistic Information Management

Solving environmental information and management problems with local participation requires the ability to combine and integrate many different viewpoints and many different bodies of knowledge about the environment. The ecology movement taught us that the environment could only be understood if seen as an integrated system and studied in an interdisciplinary fashion.

GIS stands for geographic information system, and it is variously defined as a computer-based system for the storage, management and analysis of geographic information and associated data. Perhaps its most important characteristic, however, is that it allows a wide variety of data to be integrated and combined in a formal, logical manner on the basis of spatial relationships. If a problem or data has a spatial component, a GIS allows it to be analyzed and interpreted spatially, in ways never before possible, with manual maps, tabular computer databases, or statistical techniques. The GIS is thus the first analytical tool that allows us to directly implement the ecological view of reality and to achieve a holistic information management capability, which is why it holds such promise in the struggle to solve the difficult biological and management problems that lie ahead.

This integrative capability derives directly from the advanced data processing abilities of the computer, so while many of the concepts of a GIS can be applied to manual map management systems, these are not true GISs. There are also computerized map databases and CAD systems that are only capable of graphic operations and amount to little more than a digital version of a paper map — easier to edit perhaps, but definitely not a GIS since they lack any of the analytical and integrative functions. Finally, there are many online services where you can view high-resolution imagery around the world and even display photos, GPS points, and other graphics on those images; but again, these are not GISs. They lack most of the capabilities and basic functions (see the following) that make a GIS important, the same way that watching the news on television is different from researching and writing an article on a computer.

Among true GISs, there is sometimes discussion of the differences between so-called “raster” and “vector” approaches. Raster systems divide the world into a grid of cells, each cell receiving a value. Since satellite images come in this format, raster systems are essential for processing remote sensing, and raster formats are better for some simple GIS functions. While limited, the raster model is simpler to write programs for, and many free GISs are built upon this model. Unfortunately, raster systems have historically presented greater difficulties for relational database design, since each spatial feature must be represented as a large number of cells rather than as a single exact feature. Vector systems derive from the formal mathematics of two-dimensional planar topology and relational algebra, and are generally better platforms for the sorts of data management and complex spatial and statistical analyses that a GIS is often set up for in the first place. Since each spatial feature is represented as a single entry in each table, various relationships are easier to represent in a vector system. (In modern GIS systems, like ArcGIS, both of these approaches are fully integrated.)

Role of Database Design

The capability for advanced analysis always carries a price. Data must be formally defined and structured, or the products of the analyses will have no meaning. Database design is the process whereby raw data sources, database management methods and quality control procedures, and the desired analytical operations are all integrated into a formal plan that can guide the data entry and computer programming tasks, yet is still intelligible to the end users so they can control the tendency of computer programs and databases to whirl off into irrelevancy. Formally stated, a database design must define the following:

• Data structures.

  How the data will be partitioned into tables or files and how these will be related to one another.

• Integrity rules.

  What kinds and values of data are valid for this database? What relationships represent valid real-world phenomena? How is a quality control error defined?

• Operators.

  What analytical operations will this database support? What operations will produce garbage data and must therefore be prohibited?

These design activities are often carried out by specialized consultants and analysts. A GIS cannot reach its fullest potential for integration and data sharing without such a design, in the same way a backpacker cannot achieve purposeful travel across unfamiliar terrain without a map. Unfortunately, there is no easy fix for a good database design. Designs carried out apart from the users of the system are often worthless and irrelevant. Design activities carried out by outside agencies on behalf of an organization run the same risk. To be successful, the database design process must be viewed as an intimately cooperative effort among the users themselves, and a good database-designer functions more as a facilitator between users, teaching them enough about the design process so they can control it directly, while providing an overview to help tie the different user requirements together.

The idea of teaching users how to solve their own GIS problems rather than trying to build databases or conduct analyses for them is fundamental to the philosophy of a successful and self-sustaining GIS.

Basic Functions of a GIS

Data that become part of a GIS according to clear and well-structured design then become available for a wide variety of analytical functions. These functions can perform analysis of geographic phenomena and their relationships. Some examples of these tools include the following:

• Buffer.

  A buffer is a type of proximity analysis where zones of a given distance are generated around spatial features. The distances may be arbitrary, or they may depend upon other attributes of the spatial feature, such as sensitivity. Buffers are commonly used to establish minimum protective distances around environmentally sensitive features, or to establish zones of influence around environmentally disruptive phenomena.

• Overlay.

  An overlay is the process of combining two or more spatial databases (map layers) to produce a new third database, which contains the relationships defined by the overlapping intersection or combined union of the input databases. Overlay is the basic method for combining data on a spatial basis.

• Adjacency.

  Adjacency is the process of studying how spatial features interact with their neighbors. For example, habitat quality of individual sites is largely determined by the nature of surrounding areas, whether urban, agricultural or wild.

• Dissolve.

  This is the process of joining adjacent features that share a common characteristic, allowing a larger generalized view of a pattern.

• Select.

  Spatial features can be selected and analyzed separately using spatial methods, such as all features within some arbitrary polygon or with some arbitrary distance of a point or line (buffer). The tabular data associated with this selection can be analyzed in parallel with standard statistical methods. Conversely, tabular selection processes can be applied to these tables, such as all features with value x, and the linkage between this table and the spatial data allows an immediate map to be created of the selected records.

• Topographic surface.

  The GIS can automatically calculate point and line elevation data into contour maps, slope, aspect, watershed and related analytical interpretations of terrain for three-dimensional display on terminals or other devices. Elevation, slope and aspect are critical factors in the growth and success of many species and habitats. The ability to present any data set as three-dimensional patterns combined with geography is an important analytical and visualization tool.

• Network.

  Network refers to how linear features are connected together, like roads or streams. Network software tools allow paths to be followed through such networks according to any attribute, such as blockage, flow rate and toxicity. These tools are important in modeling migration routes and stream flows.

• Relation.

  Relation refers to the unlimited possibilities for associating tabular data with spatial features. Complex many-to-many relationships, such as those found between species and sites (a species occurs on many sites and a site supports many species), can be represented and analyzed for spatial patterns.

• Model.

  A set of rules and procedures for conducting spatial analysis, drawing from all of the techniques listed previously.

The Role of GIS in Conservation

ESRI has been fortunate enough to initiate GIS and spatial capabilities at more than 5,000 different nonprofit organizations via a donation program that began in the 1980s. Our experiences with these different groups have shown that there are many critical areas of nonprofit activism that depend upon GIS and spatial capabilities to be fully effective. The following is a list of actions and needs that a broad consortium of conservation groups has listed recently as being of the highest priority. With each action is listed the sorts of GIS capabilities that are useful in resolving the problem.

Documentation:

Major effort is required to document the world’s biodiversity.

• Document species. Basic inventory GIS, coupled with remote-sensing data, allows a crude classification and a rapid overall view of a large area. This view can then be used to focus field efforts into those areas most threatened. Remote-sensing image classification is itself verified this way, but these same “ground-truth” methods can apply to complex analyses and classifications as well, such as predicting wildlife species occurrence on the basis of vegetation, slope, elevation, topography, season, land use, history, land management and proximity to settlement and roads. All of these factors can be variously combined as measures of “habitat,” defining the environment as it affects a particular species, including human effects. Such analyses can be used to prepare putative species lists for little-known areas to help guide field efforts or to help sound the alarm if endangered species might be likely to occur in a little-known area threatened with destruction.
• Basic maps of flora and fauna. Used simply as a map management tool, GIS can help organize a large collection of spatially referenced paper data by tying index maps into traditional bibliographic databases. As the next step, tabular data on each species’ characteristics, requirements and status can be collected into a database and linked with the GIS to digitized maps. The relational power of the GIS allows data to be specifically maintained about each species at each site, such as its population status and protection status at that site, in addition to separate tables giving the overall global characteristics of a species, such as biomass and life history. Once these links are made, it is then possible to conduct queries and prepare maps from questions like “map all fall-breeding mammalian species of large biomass and declining population status in less protected areas and then overlay with average autumnal rainfall and agricultural activity.”
• Practical field taxonomic aids.
• Rapid inventory methods. GIS can combine physical data, such as soils, rainfall and elevation, or use remote-sensing data to plot out draft habitat maps that can be field-edited and verified more rapidly than a ground-mapping program starting from scratch. As mentioned previously, GIS can make crude predictions on the basis of habitat of which species might be present, a technique that has already proven useful in some tabular conservation databases.
• Train more biologists and taxonomists.
• Basic microcomputer programs.

Research:

Perform ecological fieldwork to study how all the pieces fit together, using the following integrated interdisciplinary approaches:

• Effects of habitat loss and population fragmentation.
• Population dynamics.
• Habitat dependencies. Which physical and cultural factors are most correlated to observed species occurrence? Of course, such GIS research must be based on thorough knowledge of the species’ life history and natural history if it is to have any meaning.
• Explore interactions between species, habitats and human activity.
• Explore why a species is where it is. Maps of actual species occurrence overlaid with present and former extent of suitable habitat form the basis of such analyses. Maps of human history, human activity, agriculture, other species and physical environmental factors are all useful.
• Explore patterns of species’ reproductive success.

All of these efforts will rely extensively upon the integrative and modeling abilities of a GIS. The success of these efforts will depend mostly on the quality of the data obtained and the thoroughness and thoughtfulness of the database design.

Resources Management:

Define the relative environmental sensitivity of areas. Buffering and overlays would be used to combine various measures of rarity, threat and proximity in order to produce maps of environmental sensitivity.

• Determine which species and habitats are protected. Once species and habitat maps are combined with protected areas and human pressure maps, selection operations within the linked databases will reveal the percentage of range under threat for each species.
• Identify sites for protection. Modeling would be used, as in the previous examples, to flexibly reflect the criteria for site protection.
• Manage these sites. A GIS used to manage baseline data can also model different management scenarios and help guide the search for ideal management options.
• Explore alternative conservation strategies.
• Compare undisturbed and disturbed habitats as groundwork for restoration.
• Explore how locals use the resources. The ability of a GIS to combine data from such disparate sources as vegetation community mapping and demographic maps allows analysis of local economies in ecological or bioregional terms. Patterns of local livelihood and their impact on local environment can be discerned and used as a guide in management plans.

Application and Advocacy

Recent studies on the use and effectiveness of environmental information among government decision makers reveals that their most common unmet desire is to obtain information in a form that is useful to them so that they can integrate it with the rest of their activities. The dual ability of a GIS to produce information in map form or linked tabular form gives it extraordinary flexibility. Maps are among the most useful formats for information since they represent spatial patterns directly and unambiguously, compared to tables or tabular databases.

• Establish local, sectoral, and national information management systems to ensure the use of information.
• Make information available to planners and decision makers in useful forms, such as environmental status reports.
• Establish tropical research centers.
• Establish local action plans and local action centers.
• Establish national conservation strategies to define the basic agreed-upon problems and lay out the agreed-upon objectives via action plans, whose progress is monitored.
• Establish global strategies to set the framework for local and national efforts to set international priorities and develop biodiversity strategies
• Demonstrate how various management or development options will impact environmentally sensitive areas.
• Prepare evidence for hearings and impact assessment.
• Study local resource use, harvesting methodology, awareness of limiting conditions, possible alternate sources of income and ethnic diversity. What incentives are needed to change behavior that negatively affects the environment?

Monitoring:

Monitor changes in diversity, deforestation climate change and pollution over large areas, and collate information on current statuses and trends in resources to support changes in policies.

Data Management:

• Large spatial databases of the complexity needed to monitor environmental change would simply be impossible without the database management tools provided by a GIS. One example is tiling, the ability to break large databases up into smaller manageable pieces linked together in a common spatial data model and a common database definition.