Trends Analysis 
The GIS, using temporal databases such as state land 
cover, allows the user to analyze conditions over time 
(e.g., 1970, 1980, 1990) 
For example, with satellite imagery it can take current or 
historical data for a large area and show: 
+ 
extent and degree of recent development 
changes in farmland acreages over time 
forest cover changes 
loss of natural resources 
With Census data it can show trends in demographics 
such as: 
population 
nationality 
housing 
age intervals 
A GIS user can display such data to define relationships 
among the variables. 
