Toward Research-Grade Integrated Global Databases 
David A. Hastings 
National Oceanic and Atmospheric Administration 
National Geophysical Data Center 
USA 
ABSTRACT 
The Global Change Data Base results from a cooperatively developed method of publishing peer- 
reviewed data designed for integrated multivariate spatial analysis. The GCDB with accompanying 
documentation and access software lie entirely within the public domain. They are designed to (1) 
further research, education, and overall awareness of the global environment; (2) provide feedback to 
enable authors to enhance their own research and data development, and (3) provide a mechanism for 
scientists to receive credit for the intellectual content and expression of their experimental designs, 
analyses, interpretations, and models of the global environment. 
DISCUSSION 
An increasing number of laboratories and individual scientists have been developing digital spatial 
data sets that attempt to describe various aspects of the global environment. A cooperative effort over 
most of the past decade to integrate many of these data has resulted in the Global Change Data Base 
(NGDC, 1992, Gallo, 1992). Integration involves careful inspection of data for spatial registration, 
consistency between documentation and data content, and appropriateness for multivariate analysis 
and modeling in image processing, spatial statistics, and geographic information systems. During the 
development of the GCDB, several obstacles to the development of such data were assessed. A 
summary of responses to these obstacles is given below. 
Integration of Data for Multivariate Analysis: Many existing environmental data sets are produced 
individually by specialists in a particular field. These data are often designed for a special application, 
with compromises that may not be optimal for other users. The data may also have characteristics 
(cartographic projection, legend categories, simplifications) that make them difficult to use in 
integrated multivariate study. 
Many studies of the global environment emphasize only one or two types of data. For example, 
detailed studies are sometimes made of several weeks or years of Global Vegetation Index (GVI) 
from NOAA's Advanced Very High Resolution Radiometer (AVHRR), perhaps comparing such data 
with past and predicted crop yields in the African Sahel. Such data can be internally consistent but 
misregistered to the globe without significantly affecting some studies. However, attempts to 
"validate" production and processing of satellite imagery by comparisons with ground-based data can 
be greatly assisted if the separate data sets are integrated into an overall data base designed for 
multivariate application. The Global Change Data Base attempts to address this issue. Hastings and 
others (1991), Clark and others (1990) and Kineman and others (1990), discuss some aspects of this 
activity in greater detail than the present review. 
Peer-Reviewed "Publication" of Data: The design and execution of experiments that collect 
data have frequently been recognized as intellectual contributions only if the scientists involved 
produced publishable findings from the data. As such, sufficient credit may not have previously been 
given for the development of certain pioneering attempts to characterize the global environment.