Table of Contents
What are the 2 main sources of groundwater?
There are two types of groundwater contamination sources: point sources and non-point sources. Point sources include landfills, leaking gasoline storage tanks, leaking septic tanks and accidental spills; as the name implies we can point directly to the source of contamination.
What are the two dominant causes of groundwater movement?
The two most important forces controlling water movement in rock are gravity and molecular attraction. Gravity causes water to infiltrate until it reaches impermeable zones where it is diverted laterally.
What causes groundwater to rise?
The water table level can vary in different areas and even within the same area. Fluctuations in the water table level are caused by changes in precipitation between seasons and years. During late winter and spring, when snow melts and precipitation is high, the water table rises.
What are 2 things that can occur with groundwater overuse?
Excessive pumping can overdraw the groundwater “bank account”
- drying up of wells.
- reduction of water in streams and lakes.
- deterioration of water quality.
- increased pumping costs.
- land subsidence.
How is groundwater formed?
Most groundwater comes from precipitation. Precipitation infiltrates below the ground surface into the soil zone. When the soil zone becomes saturated, water percolates downward. Groundwater continues to descend until, at some depth, it merges into a zone of dense rock.
What is main source of groundwater?
Most groundwater originates as meteoric water from precipitation in the form of rain or snow. If it is not lost by evaporation, transpiration or to stream runoff, water from these sources may infiltrate into the ground.
What 2 factors affect groundwater velocity?
The velocity of groundwater flow is proportional to the magnitude of the hydraulic gradient and the hydraulic conductivity of the aquifer (see Chapter 12). Groundwater flows faster where the hydraulic gradient and/or hydraulic conductivity are larger.
What affects groundwater?
Industrial discharges, urban activities, agriculture, groundwater pumpage, and disposal of waste all can affect groundwater quality. Contaminants from leaking fuel tanks or fuel or toxic chemical spills may enter the groundwater and contaminate the aquifer.
How does groundwater flow occur?
Under natural conditions, ground water moves along flow paths from areas of recharge to areas of discharge at springs or along streams, lakes, and wetlands. Discharge also occurs as seepage to bays or the ocean in coastal areas, and as transpiration by plants whose roots extend to near the water table.
What are the three causes of depletion of water table?
It is manifested by partial or no satisfaction of expressed demand, economic competition for water quantity or quality, disputes between users, irreversible depletion of groundwater, and negative impacts on the environment. Half of the largest cities in the world experience a scarcity of water.
What are the effects of groundwater?
Effects of Groundwater Depletion
- Groundwater depletion will force us to pump water from deeper within the Earth.
- Large bodies of water will become more shallow from groundwater depletion.
- Saltwater contamination can occur.
- As large aquifers are depleted, food supply and people will suffer.
What is groundwater and how it is formed?
Most groundwater comes from precipitation. Precipitation infiltrates below the ground surface into the soil zone. When the soil zone becomes saturated, water percolates downward. A zone of saturation occurs where all the interstices are filled with water.