449 
COMPUTER GENERATION OF A LAKE DATA FILE 
FROM LANDSAT DIGITAL DATA 
J.C. Mellor 
Bureau of Land Management. 
P.O. Box 1150, Fairbanks, AK 99707 
ABSTRACT 
A computer software system has been developed that manipu 
lates Landsat digital data to compile a master file of 
lakes and their computer calculated surface features 
(i.e. area, perimeter, crenulation and centroid). Although 
the system has worldwide capability in areas of flat ter 
rain, it was conceived as a potential solution to inventory 
lakes and manage regional data for tens-of-thousands of 
uninventoried/unenumerated Alaskan Arctic Coastal Plain 
Lakes. The latitude and longitude of each lake centroid 
uniquely identify each lake in the data files, providing for 
retrieval by user specified geographic area. The data files 
contain all system calculated surface features from Landsat 
data and space for additional data from other sources. 
Sorting and filtering functions applied through retrieval of 
these data provide a lake classification capability. Pro 
posed uses of this system include: rapid lake inventory, 
change detection through repetitive inventory, consolidation 
of aquatic data, and supplementation or replacement of 
conventional means of regional lake data management and 
analysis. 
INTRODUCTION 
The software package described here identifies discrete 
lakes and acquires lake surface information from Landsat 
digital data. The system was developed because of the 
potential for a substantial increase in the data base for 
Alaskan arctic lakes and the need for consolidating this 
information into a single organized source. 
This automated analysis uses Landsat digital data to iden 
tify surface features (i.e. lake center, area, perimeter, 
and crenulation), and stores this information for future 
use. The system has worldwide application for large flat 
areas that have abundant unsurveyed or unenumerated lakes. 
Very few of the thousands of arctic lakes have been iden 
tified by name or number, or characterized by even the most 
basic limnological parameters (i.e. depth and area) asso 
ciated with each lake. The objectives for developing this 
system were threefold. The first objective was that each 
computer-generated lake identity would be unique and each 
lake would be retrievable on a geographic basis. The 
second objective was to combine the identified lakes and 
computer calculated surface characteristics into a file with 
sufficient storage space allocated for each lake to accept 
other data acquired outside this computer system. The final 
objective was to enable computer manipulation of this file 
to retrieve lake listings specific to a restricted geo 
graphic area and/or lake characteristic(s) defined by a user.