677 
INTEGRATION OF REMOTE SENSING IN A CROP/PEST MODEL USING A 
GEOGRAPHIC INFORMATION SYSTEM 
R.E. Harrison and G. Holder 
TYDAC Technologies Inc. 
1600 Carling Ave, Suite 310 
Ottawa, Ontario 
K1Z 8R7 
D.L. Johnson 
Agriculture Canada 
Research Station 
Lethbridge, Alberta 
TU 4B1 
ABSTRACT 
Grasshopper outbreaks are typical examples of large-scale spatial dynamics that are affected by local conditions. 
Data concerning these outbreaks are collected annually as point survey data. This point data is interpolated 
into thematic maps using the analytical and point interpolation techniques within TYDAC Technologies Spatial 
Analysis System. 
Currently, grasshopper population densities for the province of Alberta are derived from a variety of data sets. 
In the past simple models have enabled an annual forecast of grasshopper distribution (each August 1) from 
the previous year’s grasshopper population, monthly rainfall maps and sunlight hours during the previous 
August. 
The availability of remotely sensed data introduces another potentially data set to augment the analysis of 
grasshopper distribution. The National Oceanic and Atmospheric Administration provide vegetation indices 
derived from the Advance Very High Resolution Radiometer (AVHRR). It is anticipated that AVHRR data 
will be a useful input because it provides large scale coverage for relatively short time periods. This paper will 
examine the correlation of those vegetation indices with grasshopper population density. Application of the 
integrated grasshopper and vegetation data to developing a model describing their interrelationship is in 
progress. This paper will present the preliminary results.