Open Session - SWISS GEOSCIENCE MEETINGs

2 6
Symposium 9: Natural Hazards and Risks
high integrity positioning and assesses its performance based on various parameters such as the node density, maximal signal
range, required fraction of anchor nodes (which have GNSS positioning capability), range measurement errors, and locations
of the nodes.
Presented are results from large simulated networks (i.e. 400 nodes) and the optimal network parameters are quantified. The
requirement to have direct line of sights between stations can be solved by locating the nodes for a maximum number of
directs sights. The number of required nodes depends on the transmission range. The required fraction of GNSS enabled
reference nodes will be around 10%, depending on the network density.
Figure 1. Optimised positions of 400 sensor nodes at volcano Sakurajima.
REFERENCES
Mautz, R., Ochieng, W.Y., Brodin, G. & Kemp, A. 2007:. 3D Wireless Network Localization from Inconsistent Distance
Observations, Ad Hoc & Sensor Wireless Networks, Vol. 3, No. 2–3, pp. 141–170.
.1
Systematic recording and analysis of natural hazards along railway lines
using GIS
Andreas Meier, Christina Willi
SBB Infrastruktur, Umwelt; Naturrisiken; Schanzenstrasse 5, 3000 Bern 65
Due to the topographical conditions in Switzerland the SBB railway lines frequently are exposed to natural hazards as rockfall,
debris flow, landslide, wind and others. The safe and high disposable train service is very sensitive to changes in the
terrain. This asks for a high level of surveillance and preservation in the slopes along the railway lines.
Natural hazard data over the past 100 years and data about the currently prevailing risks exist in a variety of analogue and
digital archives or databases. Therefore it is necessary to survey the data in time and space.
With the Geographical Information System for Natural Risks (GIS NR) consisting of the tools DERI NR and WebGIS the SBB
established an important system for managing natural risks.