Preliminary report on surveying the stakeholders’ opinions
about the contents and layout of floodrisk maps
Size of the sample
The 19 questionnaires were filled in during a workshop held in Bucharest. Excepting
for 3 respondents, all others provided personal information referring to their position in water
management system, phone numbers and e-mail addresses. All respondents are employees of
Apele Romane and their answers are a little bit biased by their technical formation. Therefore
their answers need sometime more comments.
Summary on valid answers
Section 2. The general mapping formats options and information
provided
Question 1. What kind of coordinates system would you prefer?
Stereo 70
32%
Sistemul
Global
(WGS 84)
(SQ002)
11%
Sistemul
european
(ETRS)
(SQ001)
57%
Figure 1 Preferred projection systems for the risk maps
The first question refers to the type
of projection preferred by the interviewees.
The answers are presented in Figure 1 and
demonstrate that most of them prefer the
European Projection System, followed by
Stereo 70, which is being use for producing
most of the current cartographic maps.
Question 2. What information should be contained in the map
background
As shown in figure 2, the most needed graphic elements are: dikes, river networks,
street networks, human settlements,
followed by gauge stations, contour lines,
others
7
woods and shaded relief forms.
Dikes
19
Considering the target group, which is
prone to use more and capable to
14
Woods
understand more technical information,
Region names
5
we should envisage only one type of
Guage stations
15
information when choosing between
contour lines and shaded relief: probably
15
contour lines
the latter will be more suitable, because
12
shaded relief
only few people are able to see the actual
river networks
19
relief forms when only contour lines are
provided.
street networks
16
19
Human settlements
0
5
10
15
20
Question 3. What criteria should
be fulfilled by the background?
As shown in figure 3, the most
important criteria are scalability, thematic
context and similarity to topographic
maps. The multi-language support was not considered so important, although the respondents
were aware about the multinational approach. The Internet usability is also important, for 14%
of the respondents.
Figure 2 Basic information needed on the map
background
best fit to
thematic
context
33%
multilanguag
e support
5%
Scalability
32%
akin with
topographic
maps
16%
usable on
internet
14%
Figure 3 General criteria for the figuring out the map
background
Short version
for each
legend
0%
Fold out
legend
section in
atlas is
sufficient (5)
3%
Legend
should
contain an
index map
14%
Specific
legend for
each map
38%
All
information
shall be
reffered to
the legend
45%
Least
possible
information
shown
0%
Figure 4 The desired contents of the map legend
Question 4. The legend
contents
All information shall be
refereed to the legend, as shown in
figure 4. The same observation applies
here: since all respondents being
technicians or being familiar only with
technical aspects, their opinion about
the flood risk map reflects the
traditional way of conceiving the
relationship between the user and the
map, assuming that small decisions
are making now and then. Yet, the risk
map shall be used for making large
scale decisions, which affect a lot of
stakeholders:
therefore
specific
legends for each map are more
important, because the relevant
information might change from one
section of the river to another one.
Question 5. Which form of
representation of maps will
you mainly use, if provided?
This question tries to figure
out
which
combination of maps or
Printed
representations shall be used in order
maps
GIS
to
meet
the
stakeholders’
30%
Layers
requirements. Most of respondents
46%
have considered a combination of
CD/DVD
Internet with PDF
printed maps and GIS layers. It seems
maps
maps
to be a reasonable solution, because
9%
15%
printed maps will be directed to
general public, to be displayed on
public places like municipalities and
Figure 5 Types of maps preferred by most of the
similar organizations, while GIS
interviewees
correspondents will be embodied into
decision-support systems. The Internet application will play an intermediate role; it will
address a smaller group of users, but it also allows more information displayed.
Section 3. Representation of the hazard elements on the maps
Question 6. The most three important figures referring to the floods
The predefined answers are grouped in three categories (flood likelihood, water depth
and water speed), each category being further split into three different issues, referring to the
extreme, average and most frequent flood. The most frequent combination of the three
characteristics is flood frequency, flood depth and water speed, all of them referring to the
extreme floods only.
infrastructure
disaster management
Question 7 and 8.
Thresholds for water
levels, dry and flooded
areas
This important feature,
which
ensure
the
maps
Land use
consistency across countries
seems to be relevant if flooded
Environment
areas are presented in three
public services
scenarios, when it comes to water
depths: 0,25 meter, 1 meter and 4
Economy
meter. It’s reasonable to refer
Cultural heritage
only to these thresholds, because
the first one covers only floods
inhabitants health
producing small losses (each
Inhabintants
important stuff can be handled
and put somewhere above), the
Damage assessment
second threshold refers to serious
20
15
10
5
0
floods, when material damages
cannot be avoided, while the last
level
implies
a
serious
Figure 6 Most important items to be represented on the
floodrisk maps
involvement
of
authorities
responsible for life-save actions,
like firefighters and special troops, where available. Definitively, it makes sense to
differentiate on the maps the flooded areas and the dry ones.
subseqent hazards
Section 4. Representation of risk evaluation on the maps
Questions 9 and 10. Damages dimensions to be represented on the maps
and land use differentiation
According to the data presented in Figure 6, the most important features needed to be
represented on the maps are damage assessment, population and infrastructure elements.
People opinions about the other figures are diverted and, nonetheless putting more
information on such a map will turn it in a mass of cumbersome data.
Questions 11, 12 and 13: up to 10 groups of risk elements worth being
displayed on the maps and the risk criteria
Out of the 77 items listed in the questionnaire, the most important once, worth being
considered a serious risk element, are the following ones: bridges, gas pipes and fuel tanks,
electricity networks and power plants, areas where hazardous materials are deposited,
pumping stations, barrages and reservoirs. Out of 19 respondents, 11 considered the most
important criterion the location within the flooded area, and only the extreme events are worth
being considered.
Questions 14,15 and 16: the most suitable way of displaying the
information
Basically, all respondents considered that effective numbers are more impressive than
groups of human silhouettes; percentages are preferred against absolute figures, and localized
symbols for each industry are also preferred.
Section 5. Representation of risk evaluation on the maps
After the previous section
referring to the flooded areas, this
section refers to the risk assessment,
which actually is focused on the
effective use of the maps in various
planning activities, carried out at local
and regional scale.
Question 17 and 18. Activities
supported or assisted by the
risk maps and what additional
support needed for a better
risk management
Figure 7 Main activities supported by flood maps
The predefined answers cover
a lot of situation where risk maps are
to be used, from regional planning for
getting a better political support. As
shown in figure 7, rescue planning,
disaster management planning, flood
control, flood intervention plan and
authorizing
new
building
are
considered as the most important uses.
In order to make a better management in case of disaster some additional awareness
material are needed. Most of respondents came to the conclusion that leaflets, flyers and web
sites are most suitable for distributing the additional information.
Section 6. Use of flood
risk mapping for
adopting the most
appropriate preventive
measures
This section refers to how
the information provided by the
flood risk maps is further used in
planning preventive measures. As
Figure 8 Main uses when adopting preventive measures
shown in figure 8, the most important fields where the flood risk maps are being used are
equally shared by flood control activities, prevention measure, finding the rescue zones and
figuring out the safe routes in case of flood. All these elements are supporting the local and
regional strategies in case of floods, and they also support a better planning of bridges, dykes,
river banks protection and preventing the banks erosion (questions 19, 20, and 21).
The hazard maps are also important means for implementing flood protection
strategies as well as for establishing the infrastructure works needed for less than 1%
likelihood events, when it comes to designing and constructing bridges, dykes, and river
banks protections (question 22).
When it comes to large urban agglomerations (big cities), the hazard maps utility is
flawed, probably to the numerous other aspects involved, like sewage systems, rainfall
colleting systems, surfaces with different runoff coefficients and so forth. Therefore only
seven respondents actually addressed this issue in the 19 surveys.
A large majority of respondents (15 of 19) considered that risk maps are to be used for
prioritizing the measures needed for improving the water quality, including the protection of
the water table. A minor importance has been assigned to protected areas and biodiversity
conservation measures.
The climate change impact on designing the flood risk maps was considered by almost
half of respondents as important and therefore 10 of respondents considered that risk maps
shall be adapted to the new probabilities of rare events.
The most suitable institutions where these risk maps are to be stored on the web sites
are the following ones: WISE European system (11 of 19 answers), Ministry of Environment
(13 answers), Apele Romane National Administration (12 answers), watershed
administrations and the national institute of hydrology. Surprisingly, none of the interviewees
considered the INSPIRE system, which means that nobody knows about it.
The most important stakeholders involved in managing the floods in a consistent and
integrated manner are as follows: the inter-ministerial committee of water, the Ministry of
Environment, the Ministry of Administration and Interior, the National Administration of
Water,
and
the
county
inspectorates for emergency
situations and intervention.
combined
measured
23%
The next section refers to
the two types of measures needed
to reduce the flood risk,
ring dikes
structural and non-structural
4%
polders
measures. In the first categories
12%
reservoirs
are included the following ones:
continous high water
17%
dyking
afforestation works, polders,
channels
4%
8%
reservoirs, deviation channels for
high waters, continuous dyking,
ring dykes, combined measures
Figure 9 Structural measures needed to reduce the floodrisk
and greening. This type of
information is very important because it pinpoints what is necessary to address into the flood
prevention strategy, where the risk maps are to be integrated. In figure 9 one can see the
greening
6%
afforestation
26%
opinions about the structural measures needed for preventing the floods. Not surprisingly,
afforestation and combined measures are considered the most effective ways to reduce the
flood incidence.
The palette of non-structural measures is more diversified, and includes: inflatable
dykes, aluminum dykes, gabions, sacks, protective foils, improved alarms, precipitation
warnings, more accurate information about the water regime in specific areas, GSM
information, and so forth. The following non-structural measures are to be considered:
Inflatable dykes,
Improved precipitation early warning systems;
Medium term improved forecasting systems (7 days ahead);
Improved warning systems for flash floods.
The final question refers to the economic indicators suitable for being considered
when preventive measures are prioritized. A sheer cost-benefit analysis seems to be the
adequate indicator for comparing and prioritizing the measures – 15 out of 19 answers
indicated this.
Conclusions
For the time being, the most important information refers to the contents of the risk
maps, keeping in mind they will be available in two formats: printed and electronic, the latter
being used for decision making processes, like issuing licenses for new constructions,
considering the risk of being flooded. This electronic version shall be based on GIS layers, as
suggested by most of the interviewees. As for the detailed plotted onto the risk maps a
common opinion highlighted the following most relevant details: dykes, rivers, human
settlements, and streets, gauge stations and contour lines. Woods are also required for being
represented on the maps, considering that many dykes along the Danube River are protected
be forest belts placed between the riverbed and the dyke.
The activities supported by these maps are flood control, disaster management
planning, flood intervention plans, rescue and construction planning. On these maps the
following details are also needed: safe routs, preventive measures, flood protection and
control plans, as well as the rescue zones. Although many details cannot be rendered on the
printed maps, the electronic ones shall contain more details, in order to support a better
planning for preventive measures, either structural or non-structural. These measures are to be
prioritized in order to control not only the surface waters , but the water table quality as well.