Flood Mitigation Strategies - Coggle Diagram
Flood Mitigation Strategies
: Definition: A rule or a law which is enforced by an authority and which states how something should be done. Examples of regulations include zoning and elevating properties.
: Zoning is a away in which the government plans the physical development of the land and its uses. It specify the areas where residential, industrial, commercial or recreational activities may take place. Places that are flood prone are zoned as low-value developments. (e.g. parks, fields for recreational activities.) A low-value development will cost less to develop and the activities will bring less income, so cities will suffer fewer economic losses in the event of floods
-Zoning create green spaces such as parks and fields which help to reduce the impact of flood damage
-Zoning may limit the development of available land because only certain land uses are permitted.
-Zoning is difficult to carry out because of competing land uses and because people may not abide by the recommend land use
-Elevate or raise properties to a certain height.
-The minimum platform level (MPL) is 300mm above the adjacent road or ground level
-In areas that have experienced floods, the MPL is 600mm above the highest recorded flood level
Disadvantages: It is challenging to implement MPL because of the increased cost of development
Advantages: Development is protected against floods up to the height of the MPL
Investment in Infrastructure
: Cities invest in infrastructure (e.g. levees, floodwalls and channels) to reduce the impacts of the floods
Levees & Flood walls
: Levees and flood walls are barriers against floods and protect development from floodwater. Levees are raised river banks which can be natural or man-made. Flood walls are man-made structures and made of concrete. Both are built higher than the rivers so they can keep the floodwater out.
-Regular maintenance is required to ensure that levees and flood walls are strong enough to hold back flood water.
-Levees and flood walls are designed to hold back floodwater up to a certain level. They are unable to prevent floods beyond that level
-Cheaper to build levees and flood walls to mitigate and prevent floods as compared to raising the height of the surrounding land
: It refers to changes made to the river channel to increase its capacity to hold water or to enable the water to flow quickly. River channels and canals can be widened and deepened so that they can carry more storm water away. They can also be straightened so that water can be carried away quickly. This will help to prevent water in the river channels and canals from overflowing
-Channel improvement makes it possible for moderate-value to take place on the land adjacent to river channels and canals.
-Channel improvement may create problems for areas upstream or downstream of the improved area.
: Cities can take further steps to reduce the harm caused by floods. Being warned of possible floods is important in reducing flood impact. People can also be trained to be prepared and to know what to do when a flood occurs.
Forecasting and warning system
: To reduce flood risks, cities may put in place a forecasting and warning system. For forecasting to be accurate, there needs to be monitoring. Monitoring is the systematic process of collecting and analysing information to identify changes. Based on the information collected, a forecast is made. A forecast is a statement about the way things will happen in the future.
-A forecasting and warning system provides useful information so that there is time for people to take action to minimise flood damage.
-Cities may not have the expertise ad technology to collect accurate data and make accurate flood forecast.
: Cities need to have a plan to evacuate a large number of people in the shortest possible time. Evacuation drills are a form of preparedness measure where people practise the the to leave a place in a safe and orderly way during an emergency. Such evacuation drills create awareness among the people and reduce panic during a flood event. Evacuation drills involve people moving to safe locations, following instruction given by trained personnel and practising first aid.
-People are educated on what to do when a flood warning is received.
-Evacuation drills will enable cities to improve their flood evacuation plans.
-Limited participation will reduce the effectiveness of an evacuation drill.