Geography Reference
In-Depth Information
the Highland Council. The local flood management plans are developed by the
individual SEPA branch offices for the region given. The Highland Council designs
this type of documentation for the Highlands area (the northwest of Scotland). Both
of these organizations keep the same standards, structures and project issues for the
flood management plans created. Geoinformatics is implemented in the flood zones
modeling for all the watercourses in touch with the build-up area. The models are
supported with the lidar data created for this purpose for all populated areas of
Scotland. These analyses support the selection of the buildings under threat, not
only from the floods caused by rainfall, but also from the floods caused by tidal
waves.
GIS Implementation in the Case Study of a Local Flood
Management Plan
Hydrological attributes of the two streams flowing through the build-up area of the
village were determined using geodesic enquiry and the GIS analyses.
The Stream Hr
´
zkov´ potok:
Basin area up to the closing profile (until the place where the stream leaves the
cadastre): 107.89 ha
Stream length from the spring to the closing profile: 2,041 m
Average descent of the stream: 3.1 %
Basin shape: protracted (
0.143)
Type of streaming: torrential (using the Froude number where Fr
α
¼
¼
1.12)
The Stream B
´
l
´
potok:
Basin area up to the closing profile (until the place where the stream leaves the
cadastre): 129.14 ha
Stream length from the spring to the closing profile: 2,223 m
Average descent of the stream: 4.47 %
Basin shape: protracted (
α
¼
0.166)
Type of streaming: torrential (using the Froude number where Fr
1.19)
The flow rate limits of all the transversal objects which influence the drainage
conditions in the village build-up were further determined (13 piped parts of the
streams, and 9 bridges or footbridges). Two of these objects were marked as the
water gauges of category C and the flood limits for these gauges were determined
on the basis of the above mentioned hydrological computation (see Fig.
1
).
The analysis of the accumulated surface wash-down also gives relevant pieces of
information in identifying the build-up parts of the village which are under threat of
the surface water wash-down from the surrounding plots. This analysis identified
four parts in potential danger. The trustworthiness of the analysis is verified by the
accounts from the last flood event in the village in 2009 (see Fig.
2
). The maps of
the buildings under threat from both the flooding of the streams and from the wash-
¼
