Geography Reference
In-Depth Information
2.5
13
2 m model
10 m model
20 m model
40 m model
12.5
2
Gauge level
12
1.5
11.5
1
11
0.5
10.5
ASAR WSM ASAR WSM Aerial photo
TerraSAR
ASAR HH Aerial photo
RADARSAT-1
Aerial photo
0
Jul-23-00:00
10
Jul-25-00:00
Jul-27-00:00
Jul-29-00:00
Jul-31-00:00
Aug-02-00:00
(a)
2.5
13
10 m model
20 m model
40 m model
12.5
2
Gauge level
12
1.5
11.5
1
11
0.5
10.5
0
Jul-23-00:00
10
Jul-25-00:00
Jul-27-00:00
Jul-29-00:00
Jul-31-00:00
Aug-02-00:00
(b)
Figure 6.11
Comparison of water level dynamics from remotely sensed imagery and hydraulic models of different resolutions for the
July 2007 event in the town of Tewkesbury. (a) RMSE (root mean squared error) of the remote sensing-derived water level dynamics
when assessed with models of different grid resolutions. (b) RMSD (root mean squared deviation) of modelled dynamics when taking
the 2 m model results as a reference. A stage hydrograph measured at a nearby bridge is shown as a solid line. Reproduced from
Remote Sensing of Environment
, Volume 115, Issue 10, Schumann et al., The accuracy of sequential aerial photography and SAR data
for observing urban flood dynamics, a case study of the UK summer 2007 floods, pp. 2536-2546. Copyright 2011, with permission
from Elsevier.
must be correctly taken into account to reproduce the
measurements.
Pulvirenti et al. (2011b) conclude that more case studies
are required to confirm the suitability of such methodol-
ogy and to establish the requirements of an operational
flood management system.
thus may facilitate effective flood disaster management
(Schumann et al., 2007). This was illustrated in various
sections in this chapter by providing a critical account of
theories, methods and recent advances in the use of radar
imagery for flood hazard mapping and risk management.
Important to note is that, until very recently, a more
widespread application of SAR remote sensing has been
hampered mainly by a lack of adequate spatial and tem-
poral resolutions. However, with the recent launch of
satellites carrying very fine resolution SAR (typically
<
6.5 Summary and outlook
This chapter has described the utility of radar imagery in
riverine flood inundation studies. While mainly focusing
on active synthetic aperture radar (SAR) imagery, the
potential of passive radiometry for acquiring estimates of
inundation area over very large rivers or wetlands has been
briefly outlined. With the ability to acquire data during
nearly all meteorological conditions, day and night, and
its capability to provide information about the extent
of open water bodies, SARs present an alternative to
optical imagery, aerial photography, and hydraulic model
simulations for mapping flood extents over large areas and
5 m) such as TerraSAR-X, RADARSAT 2 and the
COSMO-SkyMed satellites, this situation is expected to
change dramatically. As illustrated in Section 6.4 of this
chapter, considerable research efforts are currently being
made to exploit the full potential that such high reso-
lution image data could offer to support flood hazard
modelling and risk management, even in urban areas and
with multiple images.
Recent and planned radar satellite missions dedicated
to hydrology and flood inundation studies (Table 6.5)
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