Human Effects on Hydrosphere Quality

Ways Humans Affect Hydrosphere Deforestation Agriculture Urbanization Mining Industry Power Generation Recreation Building of dams and levees Use of wells

Deforestation Reason for doing so: provide wood and farmland to accommodate human growth Effects on hydrosphere: Removing trees limits transpiration and increases soil erosion. Eroded soil, in excess, can lower the water quality of nearby streams How can we limit effects?

Agriculture Reason for doing so: feed global population Effects on hydrosphere: Maximize harvest by use of pesticides and fertilizers, along with animal waste, enter our water supply. Polluted water (nitrogen compounds), creates algae blooms, which remove oxygen from the water, creating dead zones. How can we limit effects?

Urbanization Reason for doing so: provide housing and development for increasing population. Effects on hydrosphere: Clearing of land, need for deforestation. Paved impermeable surfaces increase runoff, chemicals and metals enter water supply. Increased temperatures from urban runoff can alter river ecosystems, possibly causing a decline in a particular species. How can we limit effects?

Mining Reason for doing so: Harvest materials for use in construction, industry, power generation Effects on hydrosphere: Possible contamination of water supply from mined chemicals or metals Increased soil and rock debris in river system can damage vegetation, limit species populations How can we limit effects?

Industry Reason for doing so: Produce materials, energy demanded by consumers Effects on hydrosphere: Water and air pollution, leads to acid rain. Dumping of warm water used in production into a body of water can damage an ecosystem or even kill organisms if the temperature change is great enough. How do we limit effects?

Power Generation Reason for doing so: to have electricity Effects on hydrosphere: Water used to clean coal with scrubbers is discharged, allowing toxins into stream system which can harm organisms and lower water quality. How do we mitigate effects?

Recreation Reason for doing so: personal enjoyment Effects on hydrosphere: Accidental spilling of oil, gasoline from boating is a direct impact on water quality Trash/human waste/animal remains may contaminate watersheds if not handled appropriately while camping or fishing How do we mitigate these effects?

Building Levees Levee-usually man made structure built along rivers or oceans, often made of concrete or impermeable substrate Reason building: used to regulate water levels, prevent flooding, remove water from land so that it may be developed Effects on hydrosphere: Redistribution of water can disrupt natural flow in a watershed, limiting freshwater availability to certain ecosystems Levees can be easy transportation for pollutants.

Building Dams Dam-a barrier designed to control the flow or raise the water level of a waterway; very expensive to build Reasons for building: Power generation, control drinking water supply distribution, prevent flooding Effects on hydrosphere: Can separate organisms of an ecosystem, causing loss of a species Reservoir side becomes stagnant, effecting water quality Increases collection of sediment on reservoir side, limits flow of sediment downstream, affecting downstream habitats

Use of Wells vs. Carrying Capacity Carrying capacity is the maximum population an environment can support. As human population increases, Earth’s carrying capacity does not. The same measure of freshwater resources are being dispersed amongst a higher number of people. As a result, overpumping of wells is likely to occur, likely causing some wells to become dry.

Consequences of Overpumping Ground subsidence, or the sinking of land, is a problem caused by the excessive withdrawal of groundwater. -Overpumping near the ocean can cause the underlying salt water to rise into the wells and contaminate the freshwater aquifer. This process is called salt intrusion. -Contamination from source near the well that may have been avoided if not for overpumping.

Population Growth and Potable H20 Potable water-water that is safe for humans to drink. As human population increases, more waste is going to be generated. Coupling higher amounts of waste with a decrease in water supply increases likelihood of poor water quality and water borne diseases.

Measures to Maintain Potable Water Resources Wastewater treatment plants-sewage is treated physically and chemically and then mostly reintroduced to a river system, but some countries and states in the US are recycling water, going from “toilet to tap” Drinking water plants-major source of potable water, ground or river water is treated physically and chemically, result going straight into municipal water supply

Pollution Each of the ways we affect the hydrosphere discussed thus far mostly incorporates some form of pollution, any contaminant released in the environment that has a negative impact. Two classifications: Point source Non-point source

Point Source Pollution Source of pollutants can be traced to a discernable source. Ex: factory dumping waste EPA (Environmental Protection Agency) is given authority to issue permits to known contributors of point source pollution as means of regulation.

Non-Point Source Pollution Mostly occurs as a result of runoff, comes from many different sources. Examples: Stormwater runoff, can carry any chemical or other contaminant humans dump on land, especially concentrated in urban areas Fertilizers and animal waste from farmland runoff Sedimentation from poorly managed construction sites, or areas of deforestation

What can be done to clean polluted water supplies?

What can we do to protect our water supply? The best thing we can do is practice conservation, limiting the amount of water use. Water conservation is a sustainable practice, can limit energy production, and help to preserver habitats. Making sure we dispose of wastes appropriately can also help limit water contamination. What are some things you can do?