Human societies around the world have used timber as a building material for thousands of years. As wood is the only significant biological building material we are naturally inclined to believe that using wood in construction is good for the environment.
As a matter of fact the environmental benefits of using timber are not straightforward: although it is a natural product, a large amount of energy is used to dry and process it. Much of this can come from the biomass of the tree itself, but that requires investment in plant, which is not always possible in an industry that is widely distributed among many small producers.
Wood is also a major driver of deforestation. About a third of wood extracted from natural forests worldwide is used for timber products. In the countries that account for most of the deforestation, wood products contribute about 10% of the total. Forests—especially tropical forests—store enormous amounts of carbon. When forests are destroyed, that carbon is released into the atmosphere, accelerating global warming. Deforestation accounts for around 10% of total heat-trapping emissions—roughly the same as the yearly emissions from 600 million cars.
When not causing deforestation, timber production drives forest degradation through selective logging, where the more valuable tree species are removed from the forest. This can be more damaging than it sounds: the selective logging of one tree can damage 10 to 20 surrounding trees. Selective logging also makes a forest more vulnerable to fire and other threats and may change its suitability as habitat for some species. Selective logging can also be the first step toward deforestation: degraded forests are more likely than intact forests to be targeted for conversion to other uses.
Climate change linked to urbanization is altering the natural water cycle and nowadays water management became an issue of significant relevance.
Catastrophic events due to a wrong management of water are more and more common. Among these floods, which are Earth’s most common–and most destructive–natural hazards. A flood occurs when water overflows or inundates land that’s normally dry.
In the United States, where flood mitigation and prediction is advanced, floods do about $6 billion worth of damage and kill about 140 people every year.
Here, there are multiple laws known as the Flood Control Act that authorizes the U.S. Army Corps of Engineers to design and construct projects for the control of floods since 1928. In particular, there’s a Governative Agency called FEMA, that support citizens and is committed to respond to and recover from all hazards, like floods. This agency provides a guide to high-risk areas, indicated in the Flood Insurance Rate Map (FIRM). These areas need to get an Elevation Certificate that determines their flood insurance.
In this way, houses in these areas can be elevated according to the methods explained by FEMA regulations. The methods used to elevate a building are different depending on the type of house, the subjected area and the material in which buildings are made. The only thing in common is the amount of elevation. In fact, houses should be elevated according to the BFE of each specific area. BFE is the computed elevation to which floodwater is anticipated to rise during the base flood and can be found in the Flood Insurance Rate Map. It is recommended to rise the house up to 3 or 4 feet above the existing ground level and above the BFE, to guarantee a significant protection to the house.
On the other hand, there are also solutions that can minimize floods occurrences from the roots. Water management systems can, in fact, mitigate this catastrophic event in urban areas:
- Roof Gardens: they absorb the 50% of rainwater, reducing the quantity to dispose of in the sewer;
- Green or draining car parks: concrete car parks can be replaced with green or draining onese without loosing their function. Their permeability will be very high, up to the 95%;
- Drainage and accumulation systems: facilitate the infiltration of water in the subsoil, solving flooding system caused by major storms;
- Underground basins for water storage: reduce the quantity of water in the sewers, they naturally filter polluting materials and restore the natural hydrological balance of water in urban areas.
Systems for the drainage and disposal of rainwater are a great solution to overcome the barrier of human’s cementification. They work through “infiltration processes”, allowing water to restore its natural function and reducing the surface runoff.