Floods are natural or anthropomorphic hazard caused by intense rainfalls, snow melt, dam failures. It occurs when the soil is without capacity to infiltrate much of the volume flowed, overcoming the natural flow capacity. The excess volume that can not be drained occupies the nearby areas causing damages in many scenarios such as industries, roads, farms and houses.
Not only the geographic characteristics of different countries such as soil permeability, geology, drainage basin, size, slope and shape vary, leads to different responses for the problem by the population and competent state entities, but also the local situation, the cost-benefit analysis and political aspects.
Flood risk, speed and amount of runoff increase with climate changes, deforestation, urban development, drainage and agricultural activities. In addition, higher intensity of precipitation, changes the balance of snowfall and rainstorms. The effort to prevent floods can have a long-term effect, however as citated in classroom slides (Flood-1, slide 33) in California the reduction of 53% in floods gave a benefit cost of 1,3.
Problems such as how to deal with floods and their causes are different in each country such as Netherlands, Brazil and USA.
Netherlands has particular floods risks posed by two important large rivers: Meuse and Rhine. Also, global climate change with higher intensity of rain precipitation,increase in earth temperature and different times of water precipitation increase those risks. The country have a long history of partial and short-term solutions for flooding. Dikes and dunes protect Netherlands and water flows are coordinated by an special system of pumps, canals and sluices, for example . The country is rich which helps the implementation of all technology. The population with the government of Netherlands work together to adapt to climate change. After the evacuation of 1 in 60 in Netherlands in 1995, people’s don’t accept disregards about safety in relation to floods. Water management authorities have money, political support and technical capacity for prevention, alert and keep flood risks at a below current levels.
 In Brazil the...