Human Impacts on the

Hydrosphere

Een2.4 Evaluate How Humans Use Water

• 2.4.1 Evaluate human influences on freshwater availability– I can understand how humans use water and the

consequences of population growth, misuse and pollution of water

– I will be able to list and describe how humans use water, what the effects of overuse are, and the consequences for present and future populations

EEn2.4 Evaluate How Humans Use Water

• 2.4.2 Evaluate human influences on water quality in North Carolina’s river basins, wetlands, and tidal environments– I can understand the role of saltwater and wetlands

in aquatic systems– I will understand that water is described in terms of

both quantity and quality– I will be able to describe common sources and types

of water pollutants and their impact on surface and groundwater resources

How Do You Use Water?

How Humans Use Water

• Wells• Dams and dam removal• Aquifer depletion• Agriculture• Recreation

Misuse of Water• Over pumping wells• Subsidence – when land over an aquifer sinks

due to decrease of water• Pollution• Mismanagement

Water Pollution• Sewage– Usually from faulty septic tanks

• Industrial waste– Usually occur in ions and molecules that are not easy to

filter out– Arsenic is an example

• Landfills• Agricultural chemicals

ONCE POLLUTANTS GET INTO THE WATER IT IS VERY DIFFICULT TO GET THEM OUT!!!!!

Naturally Occurring Pollutants

• SALT – big issue in coastal areas– Freshwater layer is on top of ocean water because

salty water is more dense that fresh water– When wells in these areas are over pumped, it pulls

salt water in to the freshwater layer and contaminates the wells

• RADON – naturally occurring radioactive gas– Leading cause of cancer in the United States– Comes from decaying uranium (granite, shale)– Found in small amounts in all groundwater

Protecting Water• Identify and stop the sources of pollution

• Monitor and try to contain known sources of pollution

• Create awareness about water pollution and its effects

How Would You Fix…• Accidental spills from vehicles• Leaks from storage tanks• Seepage from acid mine drainage• Saltwater intrusion into aquifers near

shorelines• Leaks from waste disposal sites