HARD ENGINEERING DESCRIPTION ADVANTAGES DISADVANTAGES TECHNIQUE EMBANKMENTS These are raised banks -Can be used as a path for -The banks are often not along the river pedestrians beside the river. built high enough. -Concrete embankments are -Concrete embankments effective at stopping bank are ugly and spoil the erosion. view. -Earth embankments provide habitat for plants and animals. CHANNELISATION River channel may be -Effectively protects -Altering the river channel widened or deepened immediate area because may lead to a greater risk to carry more water. water is moved away quicker. of flooding, as water is May be straightened -Long lasting. carried there faster. to carry water faster. -Unnatural and visually intrusive. FLOOD RELIEF Channel course of -People close to channel safer -Needs large area of land, CHANNELS river can also be as flood water diverted to Difficult to buy if farmland. altered, diverting relief channel. -Very expensive. floodwaters away. -Used for water sports. DAMS Built along course of -Water usually stored in a -Very expensive. river to control reservoir behind dam. Then -Sediment trapped behind amount of discharge. used to generate hydroelectric wall of dam leading to Water held back by power or recreation. erosion further dam and released in downstream. controlled way. -Settlement and agricultural land may be lost when the river valley is flooded to form a reservoir. FLOOD WALLS Vertical barrier usually -Can be used in areas where They have to be made from space is limited. constructed very well so prefabricated -Easily and quickly erected in no water leaks through. concrete. pre-constructed sections. STORAGE AREAS Large depression close -Natural looking. -Need a area of land to the river that will fill -Does not damage the that is not being used. with water if the river environment. -Only come into use when overflows and the river is flooded. therefore protecting surrounding land. SOFT ENGINEERING DESCRIPTION ADVANTAGES DISADVANTAGES TECHNIQUE FLOODPLAIN Local authorities and -Very cheap way to reduce risk -Resistance to restrictions ZONING national government of damage to property. in areas of shortage of introduce policies to -Sustainable as reduces impact housing. control urban of flooding and building -Enforcing planning development close or damage. controls difficult in LIC’s. on floodplains. -Surface runoff less likely to cause flooding as floodplain not built on.
HARD ENGINEERING TECHNIQUE DESCRIPTION ADVANTAGES DISADVANTAGES EMBANKMENTS These are raised banks along the river -Can be used as a path for pedestrians beside the river. -Concrete embankments are effective at stopping bank erosion. -Earth embankments provide habitat for plants and animals. -The banks are often not built high enough. -Concrete embankments are ugly and spoil the view. CHANNELISATION River channel may be widened or deepened to carry more water. May be straightened to carry water faster. -Effectively protects immediate area because water is moved away quicker. -Long lasting. -Altering the river channel may lead to a greater risk of flooding, as water is carried there faster. -Unnatural and visually intrusive. FLOOD RELIEF CHANNELS Channel course of river can also be altered, diverting floodwaters away. -People close to channel safer as flood water diverted to relief channel. -Used for water sports. -Needs large area of land, Difficult to buy if farmland. -Very expensive. DAMS Built along course of river to control amount of discharge. Water held back by dam and released in controlled way. -Water usually stored in a reservoir behind dam. Then used to generate hydroelectric power or recreation. -Very expensive. -Sediment trapped behind wall of dam leading to erosion further downstream. -Settlement and agricultural land may be lost when the river valley is flooded to form a reservoir. FLOOD WALLS Vertical barrier usually made from prefabricated concrete. -Can be used in areas where space is limited. -Easily and quickly erected in pre-constructed sections. They have to be constructed very well so no water leaks through. STORAGE AREAS Large depression close to the river that will fill with water if the river overflows and therefore protecting surrounding land. -Natural looking. -Does not damage the environment. -Need a area of land that is not being used. -Only come into use when the river is flooded. SOFT ENGINEERING TECHNIQUE DESCRIPTION ADVANTAGES DISADVANTAGES FLOODPLAIN ZONING Local authorities and national government introduce policies to control urban development close or on floodplains. -Very cheap way to reduce risk of damage to property. -Sustainable as reduces impact of flooding and building damage. -Surface runoff less likely to cause flooding as floodplain not built on. -Resistance to restrictions in areas of shortage of housing. -Enforcing planning controls difficult in LIC’s.
river-landscape-gcse-section-a-physical-world.docx