Dealing with Natural Floods National Authority for Civil Protection Luis Sá.
-
Upload
shon-mitchell -
Category
Documents
-
view
214 -
download
0
Transcript of Dealing with Natural Floods National Authority for Civil Protection Luis Sá.
Dealing with Natural Floods
National Authority for Civil Protection
Luis Sá
Concepts
1.By popular demand we know that a flood is an overflow of an expanse of water that submerges land.
2. EU Floods directive defines a flood as a “temporary covering by water of land not normally covered by water”
3. For Civil Protection there is a concern when that land, now covered by water, is normally used by activities
that are important for the society
4. But, not all floods are bad… some are quite good…
2
Causes PT
• Fundamentally, in Portugal, floods are usually the result of high values of accumulated rainfall, which are
typically due to:
Depressions caused by convective interaction between the polar and tropical circulations,
reaching typically the South, and the regions of Lisbon, Alentejo and Algarve
Passage of weather fronts with high activity often reaching regions of the North and Center
3
Increment
• The effects of these phenomena are enhanced by:
Misuse of land;
Excessive impermeabilization of large cities;
Poor performance of pseudo-separative collectors systems;
Territorial Disordering
4
Flood Management
5
Floods Management is a serious business…
• Affects thousands of people and cause millions of euros in damage each year.
• Many of these events are impossible to predict precisely
But the disaster response community has a variety of solutions it can employ to reduce their effects.
The disaster life cycle includes several phases:
Mitigation: involves directly preventing future emergencies and minimizing their negative effects.
Preparation: include plans or preparations made in advance of an emergency that help individuals and
communities get ready.
Response: includes any actions taken in the midst of or immediately following an emergency, including efforts to
save lives and to prevent further property damage
Recovery: actions to return the community to its pre-disaster state and make it less vulnerable to future risk.
Mitigation
6
In matter of prevention the European Union published the Floods Directive (DIRECTIVE 2007/60/EC) that
requires Member States to engage their government agencies to draw up a Preliminary Flood Risk
Assessment
The information will be used to identify the areas at significant risk which will then be modelled to produce
flood hazard and risk maps
These risk maps will include detail on the flood extent, depth and level for three scenarios (high, medium and
low probability).
Step by Step
7
1. In Portugal, the Decree-Law 115/2010 established a Working Group (WG/PT) for the implementation of the
Floods Directive, which has the following entities:
- Environmental Agency
- Agency of Territorial Development
- National Civil Protection
- Azores Government
- Madeira Government
2. In simple terms we are going to cross a flood map with the land use of that territory
Floods Directive – 3 Deadlines
8
The Floods Directive has 3 major deadlines:
• 1º Preliminary Flood Risk Assessment
• by Dec 2011
PT was granted an excuse
• 2º Flood hazard and risk maps
• by Dec 2013
The EU Commission extended until JUN2014
• 3º Flood risk management plans
• by Dec 2015
Flood Intensity
9
3. The modelling will be done with software programs like HEC – HMS and HEC – RAS
4. To achieve maps of flooded areas and maps of flood intensity
5. And to obtain the flood intensity (I) in each pixel f the map
Intensity = water depth x (velocity + 0.5)
20, 100 and 1000 years
Flood Intensity
10
The working group decided to use land tools classification to define the potential consequences in a flood
event for a certain location.
We have Chosen
- Corine Land Cover (2006)
- Land Use Cartography 2007
Charting…
11
So we have a flood intensity, that must be crossed with land use…
To Have a Risk Map
Charting…
12
• A risk map is an essential tool because:
Locates and defines hazards that affect the territory;
Makes the appropriate framework for the natural dynamics;
Can be integrated into multiple sets of spatial data in geographic information systems
Response
13
• In Portugal, the water management during flood time is performed in partnership between the National
Water Institute (INAG), the National Autority for Civil Protection and dam management owners.
• There are also permanent contacts with Spanish Authorities in order to ensure the management of
flows in common rivers.
Tejo
Guadiana
Douro
Hot Spots
14
• In Portugal in terms of river floods the worst problems are located in:
River Douro, especially in Peso da Régua and Porto, tipically caused by the rainfall observed in
the right bank of the basin
River Tejo, especially in Lower Tejo, tipically caused by the discharged flow of Alcantara dam
(Spain), other portuguese dams and the rainfall observed in Ponsul and Sever tributary
basins
Early Warning - PT
15
• The Portuguese Civil Protection uses a Surveillance and Alert System for the permanent analysis on
the water resources (called SVARH)
• This system is sustained by the Environmental Agency but it can be used, at any time, by the Civil
Protection due to a cooperation agreement.
• This system allows us to follow the evolution of hydrological situation in our main basins, a fact that
can be useful to make predictions using emergency plans that contain charts with estimated flow
arrival time and expected effects
Early Warning - EU
16
Following the disastrous floods in the Elbe and Danube in August 2002, the Commission launched an activity
on the development of a European Flood Alert System (EFAS)
EFFAS does simulations of discharge with the same model providing comparable results EFAS provides for a integrated early warning system
Portugal and Spain don´t use much of EFAS because they are only 2 countries in the edge of Europe and share hydro information in a regular basis for many years
Recovery
• In matter of recovery it´s important to say that Civil Protection houses the National Platform for Disaster Reduction in the United Nations Framework. This
Platform is a multi-sector space for:
– Promotion of risk reduction and limit negative impacts of disasters;
– Creating solid institutional and political framework for ours cities
– Building resilience strategies
• In another perspective, Portugal also as Financial mechanism, the ANPC emergency account, that can support expenditure to people affected by disaster
or calamity, relating to:
a) Reconstruction and repair of housing;
b) Units of economic exploitation;
c) Coverage of other pressing social needs.
The coverage takes place only when their damage is not covered by other public entities, or other private entities like insurance companies
17
In short
18
The Main Acting principles of ANPC are:
• In Prevention Is a Flood Directive active partner
Has Emergency Flood Planning (Tejo, Douro, Mondego,…)
Does Surveillance of hydro-meteorological situation and reservoir storage
In Response Does Operations co-ordination if necessary and in the scope of emergency
plans
Cooperates with the Meteorological Authority and Water Authority
Cooperates with Local Civil Protection and Local Agents
In Recovery With the ISDR national platform, recommends Guidelines for increment
resilience
Manages the Emergency account, mobilizing supporting means and resources
Thank you [email protected]