Land use – Adaptation

Taking note of potential flood prone areas will be ever more important in the future

A central concern affecting land use is the effect of climate change on susceptibility of bodies of water and the shoreline to flooding. Particularly in the sea areas, the height of flood levels is a factor not only of the weather, but also of the characteristics of the coastal zone. This is why a universal safety limit cannot be specified. Regional environmental centres provide lake-area-specific recommendations regarding minimum construction heights.

The European Flood Directive (2007/60/EU) obliges Finland to survey potential flood areas. Finland’s flood risk mapping will be completed in 2011. It will be used as the based for drawing up more detailed maps of areas susceptible to flooding.

In built areas, heavy rain can cause flooding far away from waterways. Even small urban streams can cause considerable damage locally when flooded. Vulnerability can be reduced by increasing the capacity of the rain water network, utilising the street network, for example, to safely direct the surface runoff, reserving areas that can be allowed to safely flood in detailed land use planning or absorbing and restraining rain water locally. In normal conditions flood wetlands can function as green areas or pasture.

Climate change weakens soil properties

Changes in precipitation and freezing conditions will increase the need to take soil properties carefully into account in land use planning. Especially in clayey soils, the poor permeability of the soil intensifies the subsidence of the ground resulting from extremes in weather conditions in dry periods and the increase in instability when the soil becomes wet. For this reason too, the use of low-lying and coastal areas for building should be very carefully weighed up. Detailed planning is a powerful tool for protecting the new building stock.

Land use planning will affect how pleasant the living environment is for a long time into the future

Increasing mild winters and possible increase in wind levels will reduce the comfort of outdoor areas and increase the stress placed on the external surface of buildings. The effect will be intensified on the coasts where the open sea – ever more often during the winter too – increases the humidity of the air. The negative effects of climate change can be alleviated everywhere by positioning buildings and plantings so as to provide sheltered outdoor areas. The use of covered outdoor areas can also be considered. Good local knowledge and taking landscape characteristics and microclimate into consideration will become more important in the future.

References [1], [2], [3], [4], [5], [6], [7]