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DEVELOPMENT OF A STATEWIDE LANDSAT DIGITAL DATA BASE 
FOR FOREST INSECT DAMAGE ASSESSMENT 
Darrel L. Williams 
C. Lisette Dottavio 
Ross F. Nelson 
NASA/Goddard Space Flight Center 
Earth Resources Branch/923 
Greenbelt, MD 20771 
ABSTRACT 
A Joint Research Project (JRP) involving NASA/Goddard 
Space Flight Center and the Pennsylvania Bureau of 
Forestry/ Division of Forest Pest Management demonstrates 
the utility of Landsat data for assessing forest insect 
damage. A major effort within the project has been the 
creation of a map-registered, statewide Landsat digital 
data base for Pennsylvania. The data base, developed and 
stored on computers at the Pennsylvania State University 
Computation Center, contains Landsat imagery, a Landsat- 
derived forest resource map, and digitized data layers 
depicting Forest Pest Management District boundaries and 
county boundaries. A data management front-end system was 
also developed to provide an interface between the various 
layers of information within the data base and image 
analysis software. This front-end system insures that an 
automated assessment of defoliation damage can be 
conducted and summarized by geographic area or jurisdiction 
of interest. 
INTRODUCTION 
In 1869, the gypsy moth caterpillar (Lymantria dispar) was 
introduced to the United States by a French scientist in 
Medford, Massachusetts who had hoped to produce a new 
variety of silkworm. His experiments failed but the gypsy 
moth has managed to become established throughout the New 
England states, New York, New Jersey, Pennsylvania and 
portions of West Virginia and Maryland. Throughout the 
insect's period of establishment, gypsy moth populations 
have periodically increased to epidemic proportions. 
Currently the northeastern U.S. is experiencing one of the 
largest outbreaks recorded. Nearly 4 million hectares (10 
million acres) of hardwood forest were seriously infested 
during the insect's 1981 summer feeding cycle. Projections 
for 1982 are even higher. 
Over the years, state and federal agencies have spent 
millions of dollars developing integrated pest management 
programs which would prevent the insect's spread. These 
programs are dependent, in large part, on accurate, 
timely, and efficient methods of detecting and mapping 
incipient damage to the forest canopy. Many survey 
techniques, such as ground surveys, aerial sketchmapping 
and photointerpretation have been used to detect insect 
damage, but these techniques are becoming increasingly 
expensive to employ and the results are often subjective