3. Groundwater and Lakes Flashcards
What is a Drainage Zone?
The catchment area where surface water flows
Drainage zones play a critical role in managing surface water and preventing flooding.
Define Recharge Zone.
An area of permeable/porous rock that allows water to percolate through it
Recharge zones are vital for replenishing aquifers.
What is an Artesian Zone?
The area where water under hydrologic pressure rises back to the surface either through wells or springs
Artesian zones can create natural springs that provide water sources.
What does Recharge refer to in the context of aquifers?
The rate at which water enters the aquifer
Understanding recharge rates is essential for sustainable water management.
Define Abstraction.
Water being taken out of the aquifer
High rates of abstraction can lead to depletion of aquifers.
What is Point-source pollution?
A specific event or source that contaminates the aquifer
Examples include industrial spills or effluent discharges.
Define Non-point source pollution.
Contamination of the aquifer that comes from different sources
This type of pollution is often harder to regulate and mitigate.
What factors determine the nature of an aquifer?
Layers of different rock strata
The permeability and porosity of these layers influence water movement.
How does water quality in aquifers get affected?
By both surface water quality and high rates of abstraction in relation to rates of recharge
Effective management of both surface and groundwater is crucial for maintaining quality.
What human activities can pollute surface water that feeds into groundwater stores?
Agriculture, urbanization, and mining
These activities often introduce contaminants that can harm water quality.
What happened to Lake Chad between 1960 and 1990?
Shrunk 90% in size
This significant reduction was attributed to climate change, population growth, and unsustainable irrigation.
What climate change impact has been observed in the Chad Basin?
A rate of global warming 1.5 degrees Celsius higher than the global average
This has led to more frequent and severe droughts.
What was the Chad Basin known for in the 1960s?
The food basket region for its bordering countries
It was a significant exporter of maize and livestock during that period.
Estimate the current population size of the Chad Basin.
Over 47 million
This population has seen growth rates of between 2.5% and 3% since 1960.
Fill in the blank: The main problems impacting lakes worldwide are due to _______ projects for irrigation schemes, population growth, and climate change.
diversion
Diversion projects can lead to significant ecological and hydrological changes.
