Topic 4 ESS

Define the hydrological cycle and identify the major stores

The hydrological cycle is the continuous movement of water through the hydrosphere driven by solar radiation and gravity, with major stores including oceans, glaciers and ice caps, groundwater, surface freshwater, the atmosphere, and organisms

Describe how solar energy and gravity drive water movement

Solar energy drives evaporation and transpiration while gravity drives precipitation, runoff, infiltration, streamflow, and groundwater flow

Distinguish among evaporation, transpiration, condensation,

Evaporation is liquid water changing to vapor, transpiration is water released by plants, condensation is vapor cooling to liquid,

Explain how water moves through a watershed

Water moves through a watershed as precipitation falls on land, infiltrates soil, runs off into streams and rivers, and drains into larger bodies of water

Describe how human activities altered flows in the case scenario

Agriculture increases runoff through fertilizer use, deforestation reduces transpiration and infiltration, and urbanization increases runoff due to impermeable surfaces

Outline one positive and one negative feedback loop

A positive feedback loop occurs when nutrient runoff causes algal blooms that increase BOD and lower oxygen,

while a negative feedback loop occurs when wetlands slow runoff and filter pollutants

Explain how urbanization changes runoff and infiltration

Urbanization increases runoff and decreases infiltration because of roads, buildings, and other impermeable surfaces

Describe how deforestation affects evapotranspiration and soil moisture

Deforestation reduces transpiration and soil stability, increasing runoff and lowering soil moisture

Identify one way climate variation affects water storage

Climate change alters precipitation patterns and increases evaporation, reducing freshwater storage

Define water security and explain its components

Water security is reliable access to sufficient amounts of safe water and includes quality, quantity, accessibility, and sustainability

Distinguish between physical and economic water scarcity

Physical water scarcity occurs when water is naturally limited, while economic water scarcity occurs when water exists but people lack infrastructure or resources to access it

Identify one environmental, economic, and political factor influencing water availability

Environmental factors include climate change, economic factors include infrastructure investment, and political factors include governance and transboundary conflicts

Describe how social or cultural conditions shape access to freshwater

In many developing regions women and children are responsible for water collection, limiting access due to distance and time

Define water stress and state the general threshold

Water stress occurs when water demand exceeds availability and generally occurs below 1,700 cubic meters of water per person per year

Explain how water stress differs from water scarcity

Water stress refers to pressure on water resources while water scarcity refers to an absolute lack of water

Describe one example where inequality impacted access to safe freshwater

The Flint Water Crisis showed how political and economic inequality led to unsafe drinking water due to infrastructure neglect

Describe one example where inequality impacted access to safe freshwater

The Flint Water Crisis showed how political and economic inequality led to unsafe drinking water due to infrastructure neglect

Propose one realistic improvement to water security

Improving wastewater treatment efficiency reduces pollution and protects freshwater supplies

Explain one method of household or agricultural water conservation,

Water conservation includes reducing domestic water use and improving efficiency in food production systems

Identify major categories of water pollution and give an example of each

Organic pollution includes sewage and manure while inorganic pollution includes heavy metals and plastics

Identify two major sources of nutrient pollution

Agricultural runoff and sewage discharge

Describe how microplastics and plastics from rivers enter aquatic systems

Plastics enter through mismanaged waste and runoff and break down into microplastics that move through food webs

Explain what high or low dissolved oxygen indicates

High dissolved oxygen indicates healthy water while low dissolved oxygen indicates pollution or eutrophication

Define BOD and describe what high BOD means for an ecosystem

Biochemical Oxygen Demand measures oxygen used by microorganisms to decompose organic matter and high BOD indicates high organic pollution and low oxygen availability

Explain how pH, temperature, and turbidity affect aquatic organisms

Extreme pH harms organisms, high temperatures reduce oxygen solubility, and high turbidity limits photosynthesis and clogs gills

Identify one tolerant and one sensitive species used in a biotic index and what each indicates

Pollution tolerant species indicate poor water quality- stoneflies while pollution sensitive species indicate clean water- bloodworms

Outline the steps of eutrophication

Nutrient input leads to algal blooms followed by phytoplankton death, increased decomposition, high BOD, oxygen depletion, hypoxia, and dead zones

Explain why eutrophication can function as a positive feedback loop

Oxygen depletion causes organism death which increases organic matter and further raises BOD

Connect eutrophication to an example from field experiences

The Back River wastewater failure caused nutrient surges, algal blooms, oxygen depletion, and fish kills

Describe one prevention level management strategy

Reducing fertilizer use and limiting nutrient inputs prevents pollution at the source

Describe one control or treatment strategy

Wastewater treatment removes nutrients before discharge into water bodies

Describe one restoration strategy

Dredging(removing polluted sediments) and ecosystem rehabilitation like Marine protected areas to remove pollutants and restore impacted waters by reducing fishing pressure

Describe precipitation, infiltration, percolation, and runoff

precipitation is water falling from the atmosphere

infiltration is water soaking into soil,

percolation is water moving deeper through soil layers

runoff is water flowing over land into waterways

Distinguish between phytoplankton and macrophytes.

Phytoplankton- microscopic photosynethic organisms in oceans, seas and lakes, Macrophytes- visibly aquatic plants that are emerged, submerged or floating, both capture solar energy and support food webs, major source of global primary production

Explain why phytoplankton are essential for aquatic food webs.

Capture solar energy/supporting food webs and a major source of global primary production

State two reasons global demand for aquatic foods is increasing.

Humans influence demand due to increasing need for protein and improved incomes toward healthier options like fish + awareness of seafoods nurtritienal benefits. 

Identify one local example and one global example.

Growing demand Local of maryland blue crab, and oysters from the chesapeake. Global demand for nori, and mussels. 

Define Maximum Sustainable Yield (MSY).

highest possible catch that can be sustained over time, so used to set caps on fishing quotes.

Explain how harvesting above MSY leads to population decline and potential stock collapse.

The fish aren’t able to reproduce in their timely fashion, so the risk of collapse comes and declines on the amount of fish caught increases.

Describe the Newfoundland cod fishery collapse as a case study.

Heavy industrial fushing throughout the 20th century, plus improvement in technology with sonar and trawlers caused fish to be removed faster than they reproduce. Canadian gov declared a moratiorum in 1992, 10k plus jobs lost, stocks haven’t recovered to precollopse levels.

Identify two environmental problems linked to aquaculture.

Loss of habitat like mangrove forests for shrimp farming, Pollution from uneaten feed and waste. Spread of disease and parasities to wild populations. 

Explain one method used to reduce environmental impacts of Aquaculture.

Reduced use of chemicals and antibiotics, regulation and monitoring of aquaculture facilities, and careful site selection.

Describe one benefit of aquaculture for global food security.

Increases global food supply, supports economic development. 

Analyze how climate change may alter the availability of freshwater in different regions.

CC alters freshwater availability globally through shifting precipitation, increased evaporation, melting ice and sea level rise. 

Compare how urbanization and deforestation alter water pathways within a watershed.

Both increase surface runoff and flooding because the natura ground cover is removed. Urbanization adds engineered drainage systems and impervious surfaces, while deforestations reduces evaporation and increases streamflow and sediment. URB- channels water away faster DEF- realeses more water into system, degrades soil, slowing infiltration.

Explain how eutrophication affects energy flow and biodiversity in aquatic ecosystems.

Initiates effects, including dense algal blooms, light blockade and oxygen depletion and habitat degradation. 

Evaluate one water security strategy used in Singapore country.

Desalination by turning sea water into freshwater although energy intrusive. 

Discuss how microplastics create long-term ecological impacts through bioaccumulation and biomagnification.

Ingested into organisms, leading to physical harm and chemical toxicity, leading to bioaccumaiion with concentration in one organism and biomagnification increasing concentration up the food web.

Assess how aquaculture can be managed sustainably to protect natural systems.

With regulation and monitoring of the aquaculture facilities and reduced use of chemicals and antibiotics, they use closed systems to protect. Redyces pressure on wild stocks and imrooves water quality while creating habitats. 

Outline one strategy that your project country currently uses.

Desalination, turing seawater into freshwater. 

Propose one realistic, context-specific improvement you recommended in your project.

Desalination is energy intrusive and by possibly converting to using renewable energy it would make it cleaner.

Explain one method of household or agricultural water conservation.

Using plumbing and other water sense fixtures to cut usage and make your home sustainable.