River Basin Management Flashcards
1
Q
selection of water management site
physical factors
A
- geology - impermeable rock reduces water loss through percolation e.g. igneous rocks rather than sedimentary; rock type must be strong to support weight of dam and water
- valley shape - v-shaped valley reduces construction costs since less materials for shorter dam across valley; smaller surface area of water reduces evaporation
- tectonic activity - geologically stable preferable since earthquakes destabilise the dam which could cause damage and mass flooding
- climate - mild, moderate rainfall
- size of drainage basin - large preferable so lots of water collected; many tributaries allows water to flow straight to the river rather than infiltrating and being stored as groundwater
2
Q
selection of water management site
human factors
A
- settlements - provides workforce and makes cost of cables and pipelines cheaper; avoid towns where area needs to be flooded as high cost to rehome and compensation adds to expense
- places of historical and cultural impartance - avoided to show sensitivity to natives e.g. navajo sacred sites under lake powell; could lead to social tensions
- high value farmland - avoided as loss of income for farmer; close proximity reduces cost of water transport for irrigation
- construction materials - close by to reduce economic and environmental impact of transporting materials long distances
3
Q
impacts of water control project
socio-economic - positive
A
- expansion of irrated land allows more output and yield
- water supply for growing population
- increased standard of living e.g. pools, landscaping
- improved flood control
- more industries attracted to the area
- resevoirs provide areas for watersports and recreation improving tourism and boosting economy
- construction and maintenance of energy plants creates jobs
4
Q
impacts of water control project
socio-economic - negative
A
- evaporation makes soil saline meaning farmers have to grow salt tolerant crops
- disagreement between states over water allocation
- floods are controlled so less silt deposited of flood plains reduces fertility of soil
- displacement of people from site of dam and resevoir
- loss of sacred sites e.g. navajo burial grounds
- construction costs are extremely high
5
Q
impacts of water control project
environmental - positive
A
- reservoirs provide sancturies for wildlife e.g. blue heron
- HEP is a renewable energy source so less fossil fules burned thus reducing climate change
6
Q
impacts of water control project
environmental - negative
A
- greater evaporation rates from large areas of water which changes the hydrological cycle
- changes in flow of river leads to loss of habitats e.g. less wildlife around colorado delta
- high water loss at lake powell due to seepage through sandstone rocks
7
Q
need for water management
human factors
A
- HEP - electricity generation is required to power homes, industry and farms
- drinking water - this is used for domestic appliances etc.
- irrigation for agriculture - increased need for food production to feed growing population
- tourism - boosts economy by bringing millions of visitors to the area
- political tensions - hard to balance the distribution of water across many countries/states
8
Q
need for water management
physical factors
A
- flooding - seasonal summer rains causes flooding
- drought - low rainfall in lower basin means that there is not enough drinking water all year round
- limited vegitation - leads to soil erosion
