water resources

Question 1

What are the different components of the water cycle?

Answer 1

• Evaporation
• Precipitation
• Transpiration (loss of water by plants to the atmosphere)
• Surface runoff
• Subsurface groundwater flow

Question 2

What is an aquifer?

Answer 2

Earth materials capable of supplying groundwater from a well at a useful rate

Question 3

What is an aquiclude?

Answer 3

Earth material that stops the flow of liquid, it holds water but prevents it from being pumped out

Question 4

What is porosity?

Answer 4

Percentage of void/empty space in earth materials like soil or rock

Question 5

What is permeability?

Answer 5

Ability to transmit fluids

Question 6

What is a hydraulic gradient?

Answer 6

The gradient/slope of the groundwater surface that impacts the water table’s slope as well

Question 7

What is a hydraulic conductivity?

Answer 7

Ability of a material to allow water to move through it, measured in length per time

Question 8

What controls groundwater flow?

Answer 8

Water underground flows from areas of high pressure to areas of low pressure, and it can intercept the surface naturally (oasis) or artificially (wells)

Question 9

What causes an oasis?

Answer 9

Oases are formed when water flows underground from recharge (rainfall) areas to oasis discharge points, where it springs up through the surface

Question 10

How does water get to your faucet?

Answer 10

Water distribution systems mimic artesian aquifers in which water is stored in an elevated storage tank that creates an artificial pressure surface
Pressure drives water through the system and works its way up the pipes

Question 11

What is a cone of depression and what are the threats of groundwater pumping?

Answer 11

When water is mechanically pumped from aquifers it creates a sag in the water table known as a cone of depression
This can cause subsidence as it destabilizes soil and can dry neighboring wells

Question 12

How does groundwater pumping cause subsidence?

Answer 12

As the cone of depression grows, it lowers the water table and decreases the pressure on the soil, which causes the soil to become weaker and start to sink

Question 13

What are wetlands and why are they important?

Answer 13

Wetlands = areas inundated by water or saturated to a depth of at least a few meters for days or years
Serve to buffer areas from coastal erosion, act as natural filters and sponges, cycle nutrients & chemicals, provide habitats for species, and recharge areas for aquifers

Question 14

What are artesian wells and how do wells and springs work in general?

Answer 14

In artisan wells, water flows downward but the well confines the water and applies pressure to it
As a result of the pressure, the water flows upward towards the pressure surface

Question 15

How are aquifers influenced by permeability and porosity?

Answer 15

High porosity and permeability make for a good aquifer

Question 16

What are concerns associated with the quantity and quality of groundwater and how are they impacted by overconsumption?

Answer 16

• Ground water is a limited resource and while it can be good it is often less regulated than municipal water so it may be contaminated with chemicals
• The overconsumption of groundwater may lead to it no longer being an option, as groundwater inflow or recharge is not catching up to the demand for it

Question 17

What are the different zones in the soil that affect groundwater hydrology?

Answer 17

• Vadose zone = earth materials above the water table, rarely saturated, though heavy rainfall may change that; acts as an early warning area for potential pollution to groundwater resources
• Zone of saturation = zone or layer below the water table in which all the pore space of rock or soil is saturated (with water)
• Water table = boundary between the two zones, includes soil, alluvium, and rock