topic 4 Flashcards
Case study of human influence on the hydrological cycle with regards to agriculture
-water is artificially diverted through extraction en masse to irrigate agricultural areas, drastically changing flows and storages of cycle -> decreases available amount of water in cycle
-increases the amount of runoff in an area, which is polluted by fertilisers, pesticides, and animal waste –> results in eutrophication
example: Colarado river, usa, begins as very large but almost no water comes out of it because of the extraction for ag
Case study of human influence on the hydrological cycle with regards to deforestation
-forested areas are cleared by humans, leading to loss of biomass storage
-forests provide protection from hydrological cycle –> deforestation decreases biodiversity as species are now exposed, impacting the cycle by changing what does and does not consume it
-foliage and absorption through roots slows infiltration of water into water table, keeping soil moist for longer –> deforestation removes this, resulting in INCREASED RUNOFF and RIVER SEDIMENT
-deforestation results in a positive feedback loop reduced vegetation -> reduced evaporation -> drier climate -> less rainfall -> reduced vegetation
-decreased vegetation leads to reduced interception, more ground compaction, thus more overland runoff -> floods and flashfloods likelyhood increases
Case study of human influence on the hydrological cycle with regard to urbanisation
-natural catchment: slow surface water runoff, groundwater storage, evaporation from vegetation and surface water, infiltration into ground
-urbanisation of area: permeable surface become impermeable through paving -> results in rapid surface water runoff, limited infiltration into ground which reduces percolation and ground water storage; chance of flooding increases
-urbanisation reduces vegetation because Buildings -> reduces evaportranspiration from vegetation and surface water
-pollution of water storages (e.g. ocean,eg.g. great barrier reef) through urban runoff
Case study of how shared freshwater resources have given rise to international conflict
location: Grand Ethiopian Renaissance Dam filled from Nile River, 74 billion cubic metres of waer
when: 2021
reasons for water scarcity: arid environments
Egypt and Sudan have water rights, Ethiopia does NOT; however it runs through 11 regions and water is otherwise relatively scarce
diverting of shared resources by Ethiopia could reduce water supplies to downstream Egypt by 1/3, leading to economic agricultural loss and societal destabilisation
Case study of a controversial hunting of a named species
Species: Bowhead whale
Harvesters: Inuit people
-part of subsistence economy and traditional way of life for the Inuit
-objections because of danger of extinction and charismatic nature of species
-overruled because of traditional cultural significance and sustainability of practice unlike exploitative European whaling industry
-however permits and quotas are now imposed on communities by international treaties by colonial governments
unsustainable fishing practices and impacts
shrimp aquaculture in Thailand, beginning in 1980s
practices and impacts:
-destruction of 2/3 of Thailand’s mangrove ecosystems to accomodate shrimp ponds –> loss of breeding areas and habitats for many species, protection from coastal erosion and flooding
-high density farming of shrimps to produce as much product as possible –> rapid transmission of diseases such as Yellowhead disease
-ponds are allowed to accumulate waste products from uneaten food and faeces –> biodegration leads to anoxic waters
-these practices result in life span of shrimp pond being 2-4 years –> many deserted shrimp farms in Thailand in destroyed ecosystems
Case study of unsustainable fishing and associated (evaluation of) fishery maangement strategies
-bluefin tuna, endangered and conservation dependent
-fish stocks impacted by overfishing and illegal fishing
fishery management strategies:
-quotas for number and minimum size of fish caught
-stocks are monitored electronically
-one of 7 types of permits must be held to fish them, and can only fish with specific gear – 7000 commercial permits and 20k recreational permits issued per annum
-implementation of exclusion zone; vessels targeting bluefins must fish outside their spawn point, gulf of mexico
-illegal to sell recreationally caught fish; criminalising black market trade of them
Explain the potential value of aquaculture for providing food for
future generations
-fastest growing agricultural industry
-practiced by farmers in LEDCs and multinational corporations –> potentially able to provide food in LEDCs as well
-fish are good source of protein, fatty acids, vitamins, minerals and essential micronutrients
-aquatic plants such as seaweed are also an important resource for aquaculture as they provide nutrition, livelihood and other important industrial uses –> useful for transitions to less environmentally harmful agricultural practices
water pollution management strategies
*reducing pollutant-producing human activity: *
**implementation of alternative practices and technologies: **
-identifying and adopting less environmentally-harmful ALTERNATIVES to current fertilisers and detergents
* E.G., promoting usage of ORGANIC FERTILISERS and ECO FRIENDLY DETERGENTS can reduce the release of pollutants into water bodies
public awareness and education
-educating public about environmental consequences of activities and encouraging behaviour changes
* promoting sustainable agricultural practices, responsible waste management, water conservation
reducing the release of pollution into environment
waste water treatment
-implementing EFFECTIVE waste water treatment systems to remove pollutants (e.g., nitrates, phosphates), before discharging water back into environment
* e.g., biological treatment, chemical precipitation, advanced filtration techniques
industrial regulations
-enforcing STRICT regulations and standards for industries to CONTROL and REDUCE the release of pollutants INTO water bodies
* eg effluent dischrad limits, mandatory pollution control measures, regular monitoring and reporting of pollution levels
cleanup and restoration
remediation and restoration projects
-implementing strategies to REMOVE POLLUTANTS from CONTAMINATED sites and RESTORE ecosystems
* dredging to remove accumulated sediment
* using activated carbon or other absorbents to capture pollutants
* reestablishing native vegetation and aquatic species
ecosystem management
-adopting holistic approaches to manage ecosystems and their water quality
* integrated watershed management plans (Catchment Based Approach)
* promoting natural filtration systems (eg constructed wetlands)
* restoring riparian buffers to MINIMISE pollution runoff
