Unit 4.1-4.3

Freshwater from Earth’s water storages

Freshwater from Earth’s water storages

2.6%

Drives the hydrologic cycle

solar radiation

Storages

• organisms

• oceans

• ground water

• lakes

• soil

• rivers

• atmosphere

• glaciers and ice-caps

Flows

• Evaporation

• Transpiration

• Sublimation

• Evaporation

• Condensation

• Advection (wind)

• Precipitation

• Evapotranspiration

Transformations & Transfers

• surface runoff

• infiltration

• percolation

• stream flow

• currents

• flooding

• freezing

• melting

Impacts on surface runoff and infiltration

• Domestic water ( drinking, washing, cleaning)

• Irrigation

• Industry (manufacturing, mining, and agriculture)

• Hydroelectric  power

• Transportation (ships on lakes/rivers)

• Boundaries (states and nations)  

Ocean circulation systems

• Water has a higher specific heat capacity than land. 

• takes longer to heat up/cool down.

• land close to the oceans has a mild climate.

  • E.g. The warm gulf stream/north Atlantic drift gives Britain (and NW Europe) a moderate climate when we should have a subarctic climate.

Access to freshwater

• Lack of knowledge and skills

• Lack of finances

• Lack of political will to make water a priority

• Poor infrastructure and inadequate management of water services

• changes in precipitation

Water Scarcity

• Growing population increases need for water and food

• Climate change affecting precipitation rates and changing monsoons

• Agricultural practices can produce high evaporation rates

• Low water levels in many surface water sources

• Aquifers being exhausted due to over pumping

Solutions: Large Scale

• Build dams

• Desalination

• Rainwater harvesting

• Artificially recharged aquifers

Solutions: Small Scale

• More efficient domestic use (low flow applications and faucets)

• Grey water recycling

• Rainwater harvesting

• Drought resistant crops

• Drip irrigation

• Water at night

Case Study: The Pearl River in China

• Polluted water is killing crops in the Pearl River Delta.

• Cities are rich enough to treat the water but they do not allow farmers to use the treated water, so people are forced to drink the polluted water. Those who do fall sick.

• 9,000 tonnes of heavy metals, 66,000 tonnes of nitrates and ammonia and 60,000 tonnes of petrol are deposited into the sea every year by the river.

• The World Bank has approved a US$96 million loan to reduce water pollution.

• Guangzhou has built 30 water treatment plants which aim to cut sewage by 85%.

Rainfall patterns

heavy increase of rainfall in the past couple years

irrigation and industrialization increases

demand for fresh water increases

water supplies can be enhanced

reservoirs, redistribution, desalination, artificial recharge of aquifers and rainwater harvesting

Mexico

• gets most is not all it’s water from Colorado river which is already over used by the several states within the USA that it goes through

• Gets more rainfall then London on average per year

• still experiences droughts

• the infrastructure isn’t built to harvest the rainwater

South Africa: Capetown

• Experiencing severe drought

• Has a counter that comes closer to day 0 of easy access to water

• government announced this

• habitants by their own volition changed their water usage habits → moved the counter up

Dead Sea

• Boarders Jordan and Israel

• provides towards the economy

• consumption of it leaves sink holes

• both countries have started conflicts over it

Sustainable Yield (SY)

the amount of natural capital that can be extracted each year without depleting the stock to appoint it is not replenish-able

Maximum Sustainable Yield (MSY)

the largest yield or catch that can theoretically be taken from a species’ stock without permanently depleting the stock. (The maximum catch that will allow the population to return to carrying capacity as quickly as possible)

Carrying Capacity (K) depends on

• Reproductive strategy

• Lifespan of organism

• Limiting factors in ecosystem (resources available)

The Grind: Whaling

• Faroe Islands → Denmark

• Seasonly hunt whales

• Has been a vital part of their culture for generations

• Heavily documented and regulated

• No part of the whale is wasted

• Their main source of food

• Barley contributes to the endangerment of Whales

• Sea Sheperd: namely a french NGO that goes to the islands to stop whaling and stops hunters from doing so.

Methods of Fishing

• Dredging

• Gillnets

• Trawling

• Blast Fishing

Newfound Land

• Canada

• fisherman

• 1950s modern technology = factory style fishing

• large shipping fleets with more efficient engines

• factory fishing

• freezing fish onboard

• large trawl nets that covered large area

• more efficient detection methods to find fish → sonar tracking

• Government didn’t take action due to losing jobs which lead to a collapse in the population

Regional Fisheries Management Organisations (RFMOs)

are international organizations formed by countries with fishing interests in an area. Some of them manage all the fish stocks found in a specific area, while others focus on particular highly-migratory species, notably tuna, throughout vast geographical areas

UN Convention on the Laws of the Sea (UNCLOS)

• declared the continental shelves belong to the country from which they extend

• 200 nautical mile limit from the low water mark off the shore of a country that exclusively belongs to that county for economic use

• Outside this area is international waters

The North Pacific Anadromous Fish Commission (NPAFC)

is an inter-governmental organization established by the Convention to promote the conservation of anadromous stocks (Pacific salmon and steelhead trout) in the Convention Area

Cod wars

• 1950s to 1970s between Britain and Iceland over the rights to fish in Icelandic waters

India and Sri Lanka

• 2012 over 100 Indian fisherman killed and 350 seriously injured because of fishing along Sri Lankan coast

China

current day has increased their fishing fleet to over 200% creating conflict for fishing in waters of Indonesia, the Philippines, Japan, Korea and Russia

Impacts of open pen

• Fish higher in the food chain (salmon, tuna) still require nutrients from fish lower on the food chain leading to depletion of other species

• Loss of habitat (mangroves) to create fish farms

• Pollution of water due to fish feed and medications added to fish pens

• Increase spread of disease due to confinement in small spaces

• Often involves GMO species. If they escape may breed with wild fish

• If they escape may increase competition with native species

Optimum Sustainable Yield

• Maximum difference between revenue (fish caught) and cost (wages, boats etc.)

• Greater safety margin

• Fishing quotas based as a percentage of OSY (optimal Sustainable yield) per fleet per year. 

Icelandic cod

• Decline of stocks, government took action

• Strict quotas of trading between fishermen

• restrictions on finishing gear and fleet sizes

• diversification of target species (variety) → reduces pressure on cod

• protecting territorial waters from foreign fishermen

• Exclusion zones (fishing isn’t allowed)

  • full on ban on nursery areas

  • seasonal closure of some ares during spawning cycles

  • temp closure of fishing areas if the fish caught is too small to conserve juvenile fish

Percentage decrease

(Old Value - New Value) / Old Value] × 100]