SGIS

General System description

System name: Skog (Norwegian for forest) Geographical Information System.

Acronym: SGIS

Brief overview

The SGIS is a strategic planning system designed to aid the planner in selecting site-specific management schedules that will conform to environmental and recreational standards.

Scope of the system

SGIS is a tool for 1. Simulation of forest development and 2. Optimization of forest treatments in a GIS-user interface!

System origin

The current version of SGIS is based on a prototype developed in PC-ArcInfo (Næsset 1997).

SGIS is based on ArcView version 8 (9) and is programmed in Visual Basic for Applications.

SGIS consist of a functionality specially made for forest related problems and standard ArcView GIS-functionality.

SGIS was mainly developed for teaching and research at the university but are now also used in commercial forestry.

SGIS consists of GAYA (stand simulator) and J (mathematical programming tool). Both GAYA and J is hidden behind the SGIS windows GIS interface (ArcView)

Support for specific issues

Related systems

• GAYA-J

Data and data models

Typical spatial extent of application

The primary unit of SGIS is usually the forest stand or sometimes even a smaller unit if sufficient data for such units can be provided.

Forest data input

Digitized stands boundaries and the stand database can be imported from forest management planning systems.

Type of information input from user (via GUI)

Stand treatments schedules and spatial constraints (buffers, adjacencies, etc.). Number of 5- or 10-year periods used for calculations. Also, allowable treatments in each stand is prescribed. The planner must specify an objective function and constraints too. Otherwise, default objective function would be the maximization of NPV subject to a non-declining felling path.

Models

Forest models

Once stand treatments schedules and spatial constraints are defined, GAYA stand simulator is used. GAYA provides the future development of stand variables such as diameter, height, volume and value increment over time.

Decision Support

Definition of management interventions

Time of harvest, plantations, thinnings, reconversions...

Typical temporal scale of application

Although being data collected at stand level, the application was developed in order to join multiple stands and reach conclusions at a strategy planning level.

Types of decisions supported

• Management level
  • strategic decisions
  • administrative decisions
  • operating control decisions
• Management function
• planning decisions
  • organizing decisions
  • command decisions
  • control decisions
  • coordination decisions
• decision making situation
  • unilateral
  • collegial
  • Bargaining / participative decision making

Decision-making processes and models

• Logic modeling
• Operations research modeling
  • Direct approaches
• Simulation (with and without stochasticity)
• Multiple criteria/ranking

Output

Types of outputs

Results are displayed in tabular reports summarizing quantities, values, etc. of the optimal solution, shadow prices, and the amount of area devoted to the various treatments in each period.

They are also showed simple three-dimensional visualization of clear-felled areas in digital elevation models (DEM) as well as thematic maps presented on the computer screen or on paper showing, for example, the age class distribution of a selected period.

Spatial analysis capabilities

SGIS uses facilities of ARC/INFO in order to allow the input or edition of data and spatial constraints. Then, spatial results are showed, enabling a further spatial analysis through the comparison of previous runs where other planning strategies were used.

Abilities to address interdisciplinary, multi-scaled, and political issues

SGIS analysis tool can solve not only forest treatment scheduling problems, but also others like finding mountain sides of greater slopes than 40% suitable as goshawk habitats, corridors of old growth forest relating specific patches, etc.

System

System requirements

• Operating Systems: MS Windoes OS
• Other software needed: ARC/INFO
• Development status:

Architecture and major DSS components

The SGIS was developed by synthesizing commercially available software and well-documented software from previous forest research projects in Scandinavia. It was composed by a common menu-driven graphical user interface for the forest model and a GIS within the GIS environment. It was developed by the simple macro language (SML) facilities of pcARC/INFO.

GAYA stand simulator and JLP linear programming (LP) program are also used.

Usage

Describe the level of use: Research level use, Industry use, Government use

Computational limitations

When it was developed, those days hardware and software limitations excluded very large decision problems, owing to long response time. In the largest areas, spatial constraints such as adjacency can be unable to be solved by linear programming.

User interface

Describe the quality of user interface and the Prerequisite knowledge for using the system

Documentation and support

Describe the connection to Help-system and possibilities for assistance, as well as the required training and user support levels

Installation

• Prerequisite knowledge: Level of effort to become functional
• Cost: (purchase price, development costs, demonstrated return on investment, cost of use, training costs, licence and maintenance costs)
• Demo: allows the download/utilization of a trial version. If yes, where is it available and what are the trial conditions.

References

Cited references

External resources

• NÆSSET, E. (1997): A spatial decision support system for long-term forest management planning by means of linear programming and a geographical information system, Scandinavian Journal of Forest Research,12:1,77 — 88