Improving Environmental Assessment and Management Through a GIS-Enabled Expert System Approach

Philip Bailey
Environmental impact studies are costly and time-consuming and involve the collection, review and analysis of large volumes of information by experts. Conventional EIS/EIR approaches do not typically integrate information and knowledge in a practically applicable form. A Unique, ArcView GIS-enabled expert system is being used by land managers, natural resource managers and project developers to address this shortcoming. The system captures multidisciplinary expert knowledge, comprehensively predicts impacts, documents each analysis, pinpoints information deficiencies, rapidly facilitates "what if" evaluation of alternatives, recommends mitigation and monitoring actions, and creates a range of text and map-based reports. Once a given assessment is complete, the system is ready for use as an in-house environmental management decision support system.

Introduction

The field of environmental planning and management has been the focus of many technological developments. Proposed solutions have been varied and typically focused towards a single application or sector, such as facilities management. There remains, however, several key environmental management challenges that are not comprehensively addressed by the diverse range of customised solutions; Nobility Environmental Software Systems Inc. have targeted over ten years of research and development at these challenges in an attempt to produce a general purpose environmental planning and management software product. The result of this effort is Nobility EM, a GIS-enabled expert system. This paper outlines the Nobility EM solution, provides two brief application examples and summarises the benefits of this approach to environmental planning and decision support.

Nobility EM - A GIS-Enabled Expert System

Expert systems employ a series of rules to solve a particular problem. In the case of Nobility EM, the problem is environmental and the solution is a management or planning strategy (Figure 1 and 3). The rules, or environmental knowledge are processed by an inference engine, the core of the system. The inference engine is responsible for determining the relevant issues, or environmental impacts.

The environmental management problem is divided into two parts. First, an Environmental Description describes the environmental setting where the problem is located. Second, intended Activities are defined which are intended a part of a proposed Project.

The Nobility EM Expert System

Figure 1 The Nobility EM Expert System
The environmental knowledge is stored in the Knowledge Base and contains rules describing which activities cause environmental impacts on the components making up the environmental description. Rules are represented as two types of environmental impacts (Figure 2); A knowledge base will typically consist of thousands of impact rules. Each rule is dependent on a set of conditions occurring. For example, for the Inference Engine to determine that Fire does in fact impact Vegetation it might depend on whether a fire is within 50m of the vegetation, or whether rainfall has occurred recently, or whether dead vegetation material has been cleared.

Figure 2 Environmental Impact Structure

GIS Data and Environmental Knowledge

Frequently, attempts to develop environmental management tools have been non-spatial, despite the inherently spatial nature of many of the issues involved. Nobility EM is a spatially aware system, and as an ArcView extension, it incorporates all of the power of Esri's popular desktop GIS.

Spatial data is used to represent the environmental components and to identify the location of project activities (Figure 3). This spatial data is tightly linked to attribute information stored in a database together with the environmental knowledge. The solution is presented to the user as a series of formatted reports and digital maps, customisable for the users' specific application.

The Nobility EM Expert System Architecture

Figure 3 The Nobility EM Expert System Architecture. Adapted from Merritt, D. (1989).

Example 1: Quarry Construction

Figure 4 illustrates the simplicity of generating environmental impacts using Nobility EM. The user has drawn the location of a proposed quarry. This shapefile is displayed within ArcView, together with a background satellite image, other shapefiles have been attached to environmental components (such as animal habitats and nesting areas), but are not displayed.

The Location of Proposed Quarry Construction

Figure 4 The Location of Proposed Quarry Construction.
With a single mouse click, the Nobility EM Inference Engine interrogates the environmental knowledge and returns a list of impacts generated by the activity type Quarry Construction. The impacts are displayed in an Explorer, organised in a variety of ways, in this case, by environmental issue (Figure 5).

Quarry Construction Environmental Impacts

Figure 5 Quarry Construction Environmental Impacts.
In addition to the Impact Explorer, Nobility EM provides a spatial view of the environmental impacts using ArcView. Figure 6, demonstrates how the proximity of the proposed quarry construction to sensitive environmental components determines the degree of impact. The strongest impacts, indicated by the darkest shades of red, are closest to the quarry location with the impact decreasing outwards from the proposed activity.

Spatial Display of Quarry Construction Environmental Impacts

Figure 6 Spatial Display of Quarry Construction Environmental Impacts.


Example Reports Produced by Nobility EM

Figure 7 Example Reports Produced by Nobility EM.

Example 2: Airport Regulation Compliance

Nobility EM is an attractive technology to enforce regulation compliance. Table 1 outlines a simple example of regulations controlling subdivision development around an airport. Nobility EM was used to capture this information and represent it as a series of environmental impact rules based on the location of the Activity SubDivision Development near to a series of environmental components representing an airport infrastructure.
 
Table 1. Airport Compliance Regulations
Impact Degree Description
5 Construction is not permitted in the proposed location
4 Construction of buildings shall conform to the exterior acoustic insulation requirements
3 The development shall be covered completely
2 The development shall not include structures for the seating of spectators
1 Construction is permitted with no conditions

The environmental impact rule is based on a number of conditions. Each set of conditions is referred to as a Case, and typically has a different impact degree.

Table 2 demonstrates how the noise contours determine the degree of impact. The Spatial Relationship refers to the spatial proximity of the subdivision development to the airport. The Development Type in this example is Residential and does not change between cases. The Noise Intensity refers to the volume of aircraft taking movement, and is dictated by the proximity to the airport. In this example noise contours have been digitised and are represented as environmental components (Figure 8).
 
Table 2. Airport Compliance Rules
Rule Property Case 1 Case 2 Case 3 Case 4
Spatial Relationship on/in on/in on/in on/in
Development Type residential residential residential residential
Noise Intensity 40+ 35-40 30-35 25-30
Impact Degree 5 4 3 2

The Location of Subdivision Development near an airport

Figure 8 The Location of Subdivision Development near an airport.


Spatial Display of Impacts Caused by Subdivision Development near an

Figure 9 Spatial Display of Impacts Caused by Subdivision Development near an
Airport.

Nobility EM Applications

Nobility EM Benefits

Conclusions

There are several key challenges not addressed by existing environmental planning and management technologies. Nobility has developed a GIS-enabled expert system that addresses these challenges and represents a quick and easy way to identify and report environmental impacts. This technology can be used for a wide variety of applications, two of which are briefly described.

References

Merritt, D. (1989) Building Expert Systems in Prolog, Springer-Verlag, New York.

Acknowledgments

Thank you to the Heather Alexander, Monique Cornish, George Davis and Dennis Radage of Nobility for their advice and comments during the preparation of this paper. The screen shots for the airport application example were prepared by Heather Alexander.

Contact Information

Philip Bailey
Software Development Engineer
Nobility Environmental Software Systems Inc.
Suite 300 1765 West 8th Avenue
Vancouver  BC  V5Y 1S3
Canada

pbailey@nobility.com
Tel:  (604) 733-2996
Fax: (604) 733-4657