EHST Exam 4 (Water Resources)

Precipitation

Rainfall from clouds

Interception

Temporary collection of water on leaves in trees

Evapotranspiration

the combined process of water evaporation from the soil and transpiration from plants, transferring water from the earth's surface to the atmosphere.

Infiltration

water that has infiltrated the sub-surface

Groundwater

water that exists underground in saturated zones, filling pores and fractures in materials like sand, gravel, and rock, much like a sponge

Runoff

water that has nowhere to go (note: water can’t go through concrete)

Watershed

An area of land that drains into a specific water body

Water Basins

Similar to watersheds, but often end at the mouths of rivers

How many NC Water Basins?

17

Pitt county resides in which Water Basins?

the Tar-Pamlico and Neuse River Basins

Earth’s surface is ___ water?

71%

Total volume of water?

1.5 billion km³

__% is Salt Water

97%

__% is Freshwater

2%

_% in groundwater, lakes, rivers, soil, and atmosphere

1%

97% of the freshwater is in?

groundwater reservoirs: aquifers

___ of adult human’s body is water

65%

How many liters of water are needed to maintain bodily functions?

1-3

How many liters are needed to maintain the bare minimum essentials?

50

How many liters do developed nations generate?

200-400

2.1 billion people lack safe drinking water, and 2.4 billion lack water for hygiene. why?

In rural areas, commutes to water are long

In urban areas, lines to get water are longer

What are the top 3 water withdrawals in the U.S?

1. Thermoelectric (41%)

2. Irrigation (37%)

3. Public Water Supply (12%)

Top 6 water using states?

1. California

2. Texas

3. Idaho

4. Florida

5. Arkansas

6. North Carolina

Water Stress

when country’s available water falls below 4,600 L/d per person

Water Scarcity

when country’s available water falls below 2,700 L/d per person

Absolute Water Scarcity

when per-person water availability is < 1,400 L/d

What part of NC experiences the most precipitation?

Western NC

What happens as % (amount of imperviousness) increases?

peak stream height increases and the runoff is delivered much quicker to the stream (flashy)

Meteorological Droughts

based on rainfall

Agricultural Droughts

based on soil moisture

Hydrologic Droughts

based on streamflow or groundwater levels

Where do we get precipitation measurements from?

1. weather stations

2. Rainn gauges

3. Satelitte and radar

Where do we collect precipitation measurement data?

1. State Climate Office

2. NOAA Weather Stations

3. Volunteer Reports

What % of freshwater is ground water?

96%

__% of the U.S. water supply consists of ground water.

25%

Due to soil filtration, ground water is _________.

cleaner and purer than surface water

America’s Ogallala Aquifer, world’s largest underground water reserve, supplies how much of U.S’s irrigation water?

33%

Reduction of recharge area —

hard surfaces (roads, parking lots, roof tops)

Saltwater Intrusion

migration of salt water from ocean to wells due to excessive water level drops in freshwater aquifers

Excessive Pumping can ___ rivers and lakes.

dry up

Confining Bed

largely impermeable layers that hinder water’s movement (e.g., clay)

Aquifers

permeable rock or sediments that transmit water easily (e.g., sand or gravel

What causes degradation of ground water?

Waste storage, treatment, or disposal facilities

Septic Systems are the _____ most reported source of groundwater contamination.

third

Which sector is the largest global user and waster of water?

Agriculture, particularly through agricultural irrigation

How is irrigation water typically priced?

Irrigation water is often priced far below its true value — reducing farmers incentive to invest in more efficient irrigation technologies

How much water is wasted in agricultural irrigation?

60%, due to evaporation or seepage

What would be the impact of reducing agricultural water loss by 10%?

Could provide enough water to double current domestic use.

Water Conservation

reducing overall use, reducing waste, and recycling water for other uses

____% of water use from homes is caused by leaks.

5-10%

What is the largest consumer water use in homes is?

Toilet flushing

Altered Landscape Practices

planting lawn vegetation that dones’t require routine watering

Rain Gardens

directing runoff to landscaped areas in the yard that allow the water to infiltrate and potentially recharge the groundwater

Rainwater Harvesting

the process of collecting, storing and using rainwater for water consuming activities such as irrigation & vehicle washing

How is flooding mitigated during less extreme storms?

managing storm water runoff