D-BAUG - Departement Bau, Umwelt und Geomatik - ETH Zürich

Highlights ▪ Geo-, Structural- and Environmental Data / Highlights ▪ High-Tech Measuring Systems
The Web-Based
Swiss World Atlas interactive
Development of future-oriented teaching
material for modern geographic education.
by Ch. Häberling, H. Bär, J. Cron, Ph. Marty, L. Hurni / IKA
The Swiss World Atlas is the most widespread printed
school atlas in Switzerland and commercially very successful.
Since its first publication almost one hundred years
ago, it was entirely and partially revised several times. The
next edition will also comprise an up-to-date atlas information
system. By projecting the atlas maps as wall maps
or using them as an individual teaching aid, the screen visualizations
offer a broad range of interactive applications.
Besides classic orthogonal map representations (Fig. 1) the
Swiss World Atlas interactive also consists of virtual globes
and interactive block diagrams. The screen-optimized visualisations
offer a high standard functionality like layer management
or search tools.
With the aid of a special texture mapping method, the virtual
globe module is able to display satellite images as well
as physical and thematic global maps (Fig. 2). With the integrated
block diagrams depicting regionally and topographically
interesting landscape models – a novelty among
interactive school atlases – the students learn to better interpret
contour lines and distinctive landforms (Fig. 3). Additionally
developed visualization tools showing the revolution
of the earth around the sun (Fig. 4) sharpen the
spatial thinking of the students. All those representations
are accessible by a functional and easy-to-handle graphical
user interface.
After finishing the prototype test phase a beta version will
be available in June 2010.The official publication of the first
edition of the SwissWorld Atlas interactive is planned in October
2010 (www.swissworldatlas.ch).
70 ▪ D-BAUG Annual Report 2009
Air invasion structure
Visualization of air injection into liquid-
saturated 3D porous media.
by X.-Z. Kong, M. Holzner, W. Kinzelbach, F. Stauffer / IfU
The study of gas movement following injection into liquid-saturated
movable porous media is an active area of investigation
for theoretical and practical reasons,involving remediation,biological
processes, aeration of filters, and others. Practically,
most issues involve three-dimensional (3D) systems and therefore
a corresponding detailed description in three spatial dimensions
is extremely important for a full characterization of
the phenomena occurring.
Airinjectionpatternswereinvestigatedinfully3Dlaboratoryexperiments
under gravity effects.Using the technique of refractive
index matching between the porous medium (crushed silica
glass) and the liquid phase (a glycerine-water solution), the
air flow patterns are visualized in a non-intrusive way by tomographic
laser sheet scanning (Fig. 5).While grains and fluid
are completely transparent,air bubbles show by their very clear
contrast. By using this technique, a series of preliminary laboratory
experiments were performed in a box of the size 20 cm
× 20 cm × 30 cm using silica glass grains of size 1.0-1.6 mm as
granularmaterial.Aftersubsequent imageprocessingof the2D
slices obtained in a linear sweep of the box, a 3D dynamic air
flow pattern (Fig.6) appears,allowing a quantitative analysis of
the air flow dynamics on pore-scale.The temporal resolution of
the present configuration is 0.1 s,and the spatial resolution is 0.1
mm in plane and about 1 mm out of plane of the laser sheet .
In (Fig. 6),we can see that the invasion structure shows a fragmentation
behavior for small injection rates.Once the air bubble
elongates to a certain length, fragmentation occurs. This
means that discrete air clusters are driven by their own buoyancy.