Flood hazard and risk maps & storm water floods in Finland

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Tracy Potter
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1 Flood hazard and risk maps & storm water floods in Finland Jari Silander, Mikko Huokuna, Mikko Sane and Juha Aaltonen, Antti Parjanne Finnish Environment Institute (SYKE) Seminar on Climate Change Adaptation in the Gulf of Finland

2 CONTENTS Management of Floods in Finland Map production Climate change and urban flooding Using results 2

3 SYKE in the Finnish Environmental Administration Ministry of the Environment Ministry of Agriculture and Forestry Finnish Environment Institute Environmental Permit Authorities overall supervision Regional Environment Centres supervision of use and management of water resources

FLOODS IN FINLAND Less common in Finland than elsewhere in Europe 600 mm/year of rain no mountains lots of lakes, forests and marshes more than 200 watercourse regulations Many kinds of floods

4 FLOODS IN FINLAND Less common in Finland than elsewhere in Europe 600 mm/year of rain no mountains lots of lakes, forests and marshes more than 200 watercourse regulations Many kinds of floods melting of snow cover heavy rains thunderstorms in built-up areas formation of frazil ice inside freezing rivers ice block jams Flood damage fields, houses, roads, bridges, industry in the last 30 years the highest annual damage 5 mill the state pays compensation if the flood is exceptional

Flood damages in Finland Variation between years is a very large in 1990 total only 3 million euro (7 million lari) in 2004 about 8 million euro in 2005 about 17

5 Flood damages in Finland Variation between years is a very large in 1990 total only 3 million euro (7 million lari) in 2004 about 8 million euro in 2005 about 17 million euro in 2007 about 20 million euro Agriculture Forestry Buildings Roads and bridges Public service Industry-material Industry-productional Others Total damage

The Assessment and Management of Flood Risk From identification

6 The Assessment and Management of Flood Risk From identification to management of flood risks Preliminary assessment of flood risks ( ) flood risk assessment for all river basin districts objectives Flood mapping ( ) identifiying of areas of significant flood risks mapping of flood hazards areasmapping of flood risks Flood risk management plans ( ) measures 6

9.10.2012 Map production Floods of Pori project,

7 Map production Floods of Pori project, Detailed flood hazard mapping Hydraulic model used: HEC-RAS GIS software used: ESRI ArcGIS with Spatial Analyst and 3D Analyst extensions

8 Flood Hazard Map Flood vulnerable (GIS) Flood Risk Map Flood Risk Management Plan Flood risk maps should be developed for those areas where the flood hazard maps together with information on land use and a vulnerability assessment indicates that the potential risks of floods are significant The purpose of flood risk mapping is to contribute to the analysis of flood risks in order to support the flood risk management plans

9.10.2012 Visualisation example city of Pori city of Varkaus Kymijoki river area critical

9 Visualisation example city of Pori city of Varkaus Kymijoki river area critical flood risk areas potential significant flood risk areas flood map type Flood hazard map in detailed scale where floods occur? Flood hazard map in coarse scale [ Guidelines for flood hazard mapping on a coarse scale ] scale (max.) 1: : : background map spatial accuracy topographic accuracy terrain map generalized: no buildings, broken roads can be seen road map etc m m m +/- 0,3 m +/- 0,5 m +/- 1,8 m (nationwide DEM 25 m in Finland)

Using the risk squares Developed for emergency planning in Finland 250 x 250 m squares Based on the proved relation between building fires and number of inhabitants and floor areas of buildings Can

10 Using the risk squares Developed for emergency planning in Finland 250 x 250 m squares Based on the proved relation between building fires and number of inhabitants and floor areas of buildings Can be used as a tool for identifying areas of potential significant flood risk also other data and knowledge will be used by the experts of regional environments centres A risk zone: at least 10 risk-squares next to each other belong to the same or higher risk class Risk class Inhabitants / risk-square Floor area / risk-square Accidents / km road I > 250 inhabitants or > m 2 or > 1 per year II inhabitants or m 2 or per year III inhabitants or m 2 or 0.1 0,5 per year IV < 10 inhabitants and <250m 2 and < 0.1 per year

11 Information systems and GIS datasets eases the maintenance and provides a basis for further needs, such as development of flood risk maps INFORMATION SYSTEM

12 Map Your Risks & Get Rewarded! 12

Preliminary advances in Climate Risk Management in China Meteorological Administration

Preliminary advances in Climate Risk Management in China Meteorological Administration Gao Ge Guayaquil,Ecuador, Oct.2011 Contents China Framework of Climate Service Experience in Climate/disaster risk