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 simulation of forest development and 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 now based on ArcView version 8 (9) and is programmed using Visual Basic for Applications.

SGIS consists 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)

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 user must specify an objective function and constraints, too.

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

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.

Thematic maps presents, for example, the age class distribution or optimal treatments of a selected period.

Spatial analysis capabilities

SGIS uses facilities of ArcView 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 Windows OS
• Other software needed: ArcView, MS Excel
• 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 Visual Basic for applications language (VBA) facilities of ArcView and MS Excel.

[GAYA] stand simulator and J linear programming (LP) program are also used.

Usage

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

User interface

SGIS is an expert system. Most of the user interfase is developed using GUI, however, the definition of the forest treatments is defined in a command file.

Documentation and support

A user manual (in Norwegain) is provided.

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