GEOLOGY

Detailed explanation-1: -Defenses such as dykes, reservoirs and dams are used to keep rivers from overflowing. A dam is one of the methods of flood protection, which reduces the risk of flooding compared to other methods, once it can help preventing damage.

Detailed explanation-2: -Construct building-scale rainwater tanks, green walls and other building-scale green infrastructure, such as green roofs. Building-scale rainwater retention tanks collect rainwater runoff from roofs to reduce the amount of water that flows into the city’s streets and waterways.

Detailed explanation-3: -Dikes, Levees, and Floodwalls These works may have adverse as well as beneficial effects. They can increase the height of the flood immediately upstream, across the stream, and downstream by reducing the amount of floodplain area available for overbank floodwater conveyance and/or storage.

Detailed explanation-4: -Coastal management. Dams. Diversion canals. Floodplains and groundwater replenishment. River defenses. Coastal defenses. Self-closing flood barrier. Temporary perimeter barriers.