1. Faculty of geosciences
Conversion of digital elevation maps to geological information
Aart-Peter van den Berg van Saparoea
Utrecht University, Department of Earth Sciences, Budapestlaan 4, 3584 CD Utrecht, The Netherlands
phone: +31 (0)30 253 5119, fax: +31 (0)30 253 5030, e-mail: apvdbvs@geo.uu.nl
Time
Sea-level
river shelf
erosion surfaces
river shelf basin
Space
Time
erosion surfaces
raw data (sequential DEM’s)
erosion and
deposition patterns
geological maps
geological sections
analysis software
scan (photogrammetry or laser)flume
We are developing software to perform this task. The core of the system consists of a set of
algorithms which calculate deposition and erosion of sediments from series of raw x, y and
z coordinate sets. The results of these calculations can then be used to construct geologi-
cally meaningful objects, such as formations and erosion surfaces. On top of this is a layer
of software that automates information storage, retrieval and visualisation. This dramati-
cally cuts the effort required to produce geologically meaningful results. Finally, the system
has an easy to use graphic user interface. The system uses only ASCII format text files con-
taining x, y and z coordinates as input, allowing maximum flexibility and compatibility.
Information produced by the system includes basic erosion/deposition
maps, geological maps, geological sections, plots of the amount of time
contained in hiatuses and Wheeler diagrams. Modular design allows
easy addition of functionality to the basic framework as needed.
DEM
A DEM is the equivalent of a stratigraphic surface of a single age. There-
fore a data set of successive DEMs not only contains a large amount of
‘geological’ information on the final stratigraphy of the system, but on
the entire development of the system in three dimensions through time
as well. The challenge is to retrieve and visualise this information.
Wheeler diagrams
Data obtained from flume experiments consists primarily of successive digital elevation
models (DEMs). Comparison of this type of information with geological field data is difficult.
We have developed software to solve this problem.