International Archives of Photogrammetry and Remote Sensing. Yol. XXXII Part 7C2, UNISPACE III, Vienna, 1999 
111 
/^m\ 
15PR5 
UNISPACE III - ISPRS/EARSeL Workshop on 
“Remote Sensing for the Detection, Monitoring 
and Mitigation of Natural Disasters” 
2:30-5:30 pm, 22 July 1999, VIC Room B 
Vienna, Austria 
(d) the ability to acquire the data in inaccessible 
territory, where it cannot be collected by 
conventional techniques 
The existing remote sensing satellite systems such as Landsat, 
SPOT or IRS enable the acquisition of the information in real 
time over the requested territory. They have different spatial and 
spectral resolutions and can provide numerous imaging 
possibilities over an investigation area. The contemporary 
Landsat system TM (Thematic Mapper) is characterized by 30 m 
geometric resolution; SPOT has 10 m resolution panchromatic 
mode and 20 m in multispectral mode; and the Indian IRS has 5 
m resolution in panchromatic mode. The new generation of 
commercial remote sensing satellites will have much improved 
resolutions. For example, the American Early Bird 1 produced by 
Earth Watch corporation, launched on 24th December 1997 has 
resolution of 3 m which is comparable with high altitude aerial 
photographs. 
Revisit tune, also called temporal resolution, refers to the 
possibility of acquiring consecutive images of the same territory'. 
Revisit capability is dictated by the sequence of satellites orbits. 
For the early stage of remote sensing satellite systems, revisit 
times ranged from 16 to 24 days, due to the fact that images were 
only taken in nadir mode along the satellite track. The 
contemporary systems allow the recording of images in cross 
track mode, hence shortening the revisiting time to a few days. 
For example, the images taken by Early Bird 1 can be acquired 
every two days for higher latitudes and every 5 days for 
Equatorial regions. The new generation of the remote sensing 
radar satellites which operate in the microwave range, permit the 
registration of images independently of weather conditions. This 
is very' important in the case of data acquisition for a specific 
time. 
Besides the remote sensing satellites, the data collected by 
NOAA meteorological satellites can be also used as 
supplementary and complementary data to remote sensing data. 
These meteorological remote sensing data have lower spatial 
resolution, but very high temporal resolution, thus allowing 
several revisit images of the same area during one day. The 
sensors of meteorological satellites often operate in different 
spectral bands than Earth surface observation satellites. The data 
collected by these satellites in the medium and far-infrared part 
of the electromagnetic spectrum can be used for estimation of 
soil moisture and surface temperature. Such data are veiy 
important in the prediction of forest fires and for determining 
areas indicating high fire potential. 
THE ROLE OF REMOTE SENSING IN FLOOD 
DISASTERS 
Each year flooding appears all over the globe and veiy often it 
has a regional and international character. The monitoring of the 
extent of flooding is very important both for the registration of 
damage caused by water, and for application of these data in the 
information systems used for forecasting floods. 
The summer 1997 flooding of the Oder River affected the Czech 
Republic, Poland and Germany causing tremendous damage in 
towns, settlements and villages situated in the vicinity of the 
river, as well as the destruction of the natural environment. In the 
Czech Republic about 20% of its territory was under water. In 
Poland, over 500,000 ha were under water and several hundred 
villages and towns were partially affected by the flooding. This 
disaster indicated the necessity and importance of: (a) 
international cooperation during the disaster and (b) preparation 
of homogeneous systems focused on the prediction and 
prevention of flooding disasters. Up to now there are no 
homogeneous systems which can be used for forecasting floods, 
or for the proper protection of areas which can be affected by the 
floods. 
In the summer 1997 flood in Poland, aerial photographs were 
taken to monitor the water’s extent, from the commencement of 
rising water levels in the upper part of the Oder River. The aerial 
photographic missions were performed daily, hence the water 
levels and changes in the extent of affected areas were registered 
and dynamics of the flooding processes indicated. The aerial 
photographs were taken along the river course, with the scale 
determined by the width of the flooded areas and the weather 
conditions. This resulted in scales of aerial photographs vary ing 
between 1:14,000 and 1:25,000. Each day immediately after the 
photographic mission, the aerial photograplis were developed 
and delivered to the Central Antiflooding Committee and to the 
regional and local antiflooding committees. These data were used 
for evaluating the extent of flooding, and for making decisions on 
protection of the areas which may be affected by the floods, and 
the evacuation of inhabitants from villages and towns. More 
than 130,000 people were evacuated from their houses in Poland. 
In the post-flood stage, the aerial photographs were used for 
assessing the damage caused by the flooding at the local level. 
Altogether, 2,500 aerial photographs were taken during July 
1997 over the areas affected by the flooding. 
Aerial photographs were also used in the Czech Republic and 
Germany. In the Czech Republic over 4,500 aerial photographs 
were taken by several photogrammetric institutions. In Germany, 
the aerial photographs were taken by the Luftwafe over the Oder 
River within the programme of Open Sky. It should be 
underlined that the Germany delivered copies of these 
photographs to their Polish partners. 
In addition to aerial photographs, satellite images were collected 
for monitoring the flooding. Unfortunately, due to very bad 
weather conditions and poor timing of the acquisition of the 
images, only a few scenes were recorded during the floods. There 
were only a few Landsat images and one IRS scene, each of 
which was partially covered by clouds. However, radar images 
recorded by ERS-1 and ERS-2 satellites, provided a valuable 
source of space information acquired during the flooding period. 
By a request of the Institute of Geodesy and Cartography in