Water Resources Flashcards
exam questions
What is eutrophication? How does it change water quality?
Eutrophication is pollution by adding plant nutrients.
Eutrophication sets off a chain reaction in the ecosystem, starting with an overabundance of algae and plants. The excess algae and plant matter eventually decompose, producing large amounts of carbon dioxide. This lowers the pH of seawater, a process known as ocean acidification.
more nutrients –> more plants in water –> more decomposition, increasing presence of CO2 –> more CO2 lowers the pH –> ocean acidification
Why is cyanobacteria deemed to be harmful in water bodies?
The presence of cyanobacteria is very concerning.
- Capable of creating its own source of ammonia, which results in the domination of this algae.
- The algae forms large mats that wash up on shores or it forms sludge over benthic zones and causes oxygen sags (chokes marine life)
- Cyanobacteria often excrete toxins (neuro or hepato) that cause liver or brain damage, or death.
What conditions favor cyanobacteria? Why is this?
Conditions
1. warm
2. slow-moving waters
3. rich in nutrients
These conditions allow for the bacteria to multiply quickly.
What is the link between agriculture and water quality?
The link would be runoff from agricultural fields, containing large amounts of nutrients. The runoff then finds its way to water bodies where the water quality is directly affected by the excess nutrients present.
How can sustainable agriculture that considers water quality be promoted?
Promoting sustainable agriculture would include educating farmers on the amount of fertilizer lost through runoff. By promoting methods like conservation tillage, buffer zones and the integration of animal husbandry into agricultural fields, it will cost less in the long term for the farmer while also preserving the water quality of nearby rivers and lakes. By promoting sustainable agriculture through the lens of economic efficiency, the problem of runoff affecting water quality will be solved.
How is sewage treated before it is discharged?
- Primary Stage - solids are allowed to settle and removed from wastewater.
- Secondary Stage - uses biological processes to further purify wastewater.
- Tertiary Stage - reduces nutrient loads from effluent
What is the process of groundwater recharge?
Natural groundwater recharge occurs as precipitation falls on the land surface, infiltrates into soils, and moves through pore spaces down to the water table; can also occur as surface-water leakage from rivers, streams, lakes, and wetlands.
What are the problems with Lake Winnipeg? What are some solutions?
Problems
1. invasive species
2. changes in land use
3. land and water management practices
4. fishing pressures
5. extreme eutrophication
Solutions
1. limiting and regulating activity that generates a surplus of the nutrient in waterways
2. restoration of wetlands
What is demand management? How does this promote a smaller water footprint?
Demand Management - approach that aims to conserve water by influencing demand
It promotes a smaller water footprint through implementation of selective incentives to promote efficient and equitable use of water.
When insufficient sources of fresh water exist, what are strategies that offer alternative sources?
- Recycling of wastewater
- Developments of energy efficient desalination plants
What is that hydrologic cycle? How does it generate freshwater?
Hydrologic Cycle - occurs through pathways of precipitation and evapotranspiration; water continuously circulating through the environment.
Generate Freshwater - Through the hydrologic cycle, fresh water is purified and regenerated continuously.
*must be allowed adequate time for regeneration
What is salinization?
An increase in salt content (agricultural soils, irrigation water, drinking water)
How can you manage pollution to ensure that there are healthy water bodies?
- Isolate activities within the watershed to minimize contamination
- Development of wastewater treatment facilities
- Encourage development of buffer zones on agricultural fields to slow runoff
What is the current state of the Ogallala Aquifer? How could this be a problem in relation to climate change?
Ogallala Aquifer - Shrinking due to heavy demand for irrigation
Problem - With a warming, soil moisture in the region would be reduced, as would rainfall and would increase the need of these aquifers to supply for human need but would be unable to because irrigation has not allowed for proper regeneration.
Why are riparian areas so important in sustainable management?
- Preserves water quality
- Provides habitat for wildlife
- Provides aesthetic and recreational value
