Information Technologies for Forest Management in Vietnam

FOREWORD

Generally, in any program or project concerned with natural or environment inventory, the map is a special, important datum but no more so than in forestry. ‘Forest’ is an object that is not only often large and remote but is constantly changing. This makes forest mapping particularly difficult work.

Prior to 1979, Vietnam completed a forest map using air-photo and traditional methods for the micro level at enterprise, district, or province levels only. By 1979, with support by FAO, for the first time a forest map of the whole territory of Vietnam using remote sensing techniques had been completed after two years of work. This was an important event in the history of forest mapping in Vietnam.

Nowadays, information technologies have been broadly adopted and are employed in all mapping activities. Consequently, they are becoming effective tools for natural and forest resources management.

OBJECTIVES OF INFORMATION TECHNOLOGIES APPLICATION IN FORESTRY

• Assessment of forest resources as seen from the broader concept of a forest ecosystem from which highly accurate data and information will be annually/periodically supplied for both forest management planning and long-term forest monitoring at macro levels.
• Establishment of a computerized database and GIS system and a permanent sample system as a basis for long-term monitoring and research on forest resources.
• Assessment of the changes of forest resources during periods of 1976-1990-1995- 2000 and following periods which help future forest forecasts.

METHODS USED:

To get information from remote sensing data all basic methods have been used, such as:

• Visual interpretation
• Digital image classification
• Field survey and correction

Depending on technical and financial issues, these methods may be used separately or integrated.

CLASSIFICATION FOR MAPPING

The Classification is based on FAO Classification

TECHNICAL STEPS OF VISUAL INTERPRETATION

TECHNICAL STEPS OF DIGITAL IMAGE CLASSIFICATION

MATERIAL USED

Base maps:

Base maps used for forest mapping are topographical maps including the scales and projections as follow:

Remote sensing data

The satellite images Landsat-MSS, Landsat-TM, and SPOT are used as the main sources for photo-interpretation. Based on the objective and content of the map as well as map scales, one must identify which of the above satellite images is the best suited for interpretation .

• The Landsat-MSS is suitable for forest mapping at the scale from 1:1.000.000 to 1:500.000 ( maximal scale 1:250.000 ).
• The Landsat-TM is suitable for forest mapping at the scale of 1:250.000 and maximum 1:100.000.
• The SPOT images are suitable for forest mapping at scales from 1:100.000 to 1:50.000 (maximum 1: 25.000 ).
• Remote sensing data used for forest mapping should not be older than one year from the date of mapping and geometrical correction.
• Various specialized thematic maps (e.g., Historical Forest Map, Land Use Map, Ecological Map, Soil Map and Topo Map) are also used as important reference sources in photo-interpretation. In this context, aerial photographs may also play an important role .

The Chart of Sampling Plot

Forest area changes in 20 years

unit: 1.000 ha

Forest cover percentage in 50 years

CONCLUSION:

In tropical countries, such as Vietnam, that have multiple-forms of natural geography, natural resources and environment, their management cannot be effective without employing remote sensing applications. The improvement of natural resource and environmental management in Vietnam over the last twenty years demonstrates the importance of using new resource management technologies such as remote sensing, GIS & GPS.