[ APES ] Ch 13: Water Resources [ P2 ]

What are the benefits & harms of flooding?

+ • productive farmland • recharge groundwater • refill wetlands - • kills ppl

List 4 ways to reduce water waste in industries & homes

1. Recycle water in industry 2. Fix water leaks 3. Landscape yards w plants that require little water 4. Drip irrigation on gardens & lawns

List 2 human activities that increase risk of flooding.

1. Removal of water absorbing vegetation • freshwater from precipitation rushes down deforested areas, increasing flooding 2. Draining of wetlands • ex-wetlands covered w pavement/buildings, creating runoff

What is a floodplain?

The area flooded w freshwater

Summarize the story of the Aral Sea water transfer project & its disastrous consequences.

The two rivers that supplied water to the Aral Sea were diverted. This along w the dry climate has had negative consequences. The Aral Sea lost 90% of its water, 85% of wetlands are lost, 50% bird & mammal species became extinct, increased salt concentration devastated the fishing industry, altered climate change, & melting glaciers faster

What is a water transfer?

Transferring water from water-rich areas to dry areas

What % of available freshwater is lost through inefficient use & other causes, in the world & in the U.S? What are 2 major reasons for those loses?

World: 66% U.S: 50% • evaporation • leaks • inefficient use 1. Cost of freshwater to users is low (underpricing water) 2. Lack of gov subsidies for improving efficiency of freshwater use

Describe 3 major irrigation methods & list ways to reduce water losses in irrigation.

1. Center-pivot, low-pressure sprinkler • pumps spray water on crops, 80% of water reaches crops 2. Low-energy, precision application sprinklers • 90-95% reaches crops 3. Micro irrigation • Network of tubes w holes delivering water @ a slow & steady rate • irrigate @ night • drip irrigation • avoid growing thirsty crops in dry areas

What are 3 ways in which ppl in less developed countries conserve water?

1. Human powered treadle pumps brain water up to the surface • inexpensive& easy to build, uses 60-70% less water 2. Buckets, small tanks w holes, plastic tubing systems for drip irrigation 3. Rainwater harvesting • storing rainwater for use during dry season, simple & inexpensive

Describe 2 large water transfer programs. Explain how they came about. Summarize the controversy around each of these programs.

China: • rapidly growing & urban populations depleted aquifers • massive water transfers involve high social & economic costs, large water loss from evaporation, & degraded ecosystems CA: • need water for irrigation • degraded sac river, threatened fisheries, reduced the flushing action that helps cleanse pollution

List & compare 2 engineering approaches to flood control & 2 ecologically oriented approaches.

Engineering 1. Channelizing of streams • reduces upstream flooding (+) • eliminates aquatic habitats (-) 2. Damming • reduces flooding by storing water (+) • a lot of drawbacks (-) Ecological 1. Preserve existing wetlands 2. Restore degraded wetlands • take adv of natural flood control • reduces greenhouse gas emissions - slows climate change --slows rising sea levels

Define desalination. List 3 major limitations in the widespread use of desalination What are scientists doing to try to deal w these problems?

Process of removing dissolved salts from ocean water or from water in aquifers/lakes 1. Expensive: needs a lot of energy to remove salt from water 2. Kills many marine organisms 3. Huge quantities of salty wastewater Working to develop better & more affordable desalination technology

Why do ppl like to live on floodplain?

• fertile soil for crops • freshwater for irrigation • nearby rivers = transportation & recreation

How can we use less water to remove wastes?

• recycle & reuse gray water for cleaning equipment & watering lawns/crops • rely more on waterless composting toilets

Describe the flooding risks that many ppl in Bangladesh face & what they're doing about it.

• severe flooding Bc of deforestation of coastal mangrove forests • using varieties of rice/other crops that can tolerate flooding • building ponds that will collect monsoon rainwater