Surface Water

Definition

Surface water refers to any body of freshwater or saltwater that is found on the Earth's surface, including rivers, lakes, streams, and reservoirs. It plays a vital role in the hydrologic cycle by providing water for evaporation and serving as a primary source of drinking water, irrigation, and habitat for aquatic ecosystems.

5 Must Know Facts For Your Next Test

1. Surface water is essential for maintaining ecosystems, supporting both plant and animal life within aquatic environments.
2. Approximately 70% of the Earth's freshwater is found in glaciers and ice caps, while surface water sources like lakes and rivers contain only about 0.3% of the total freshwater supply.
3. Surface water is influenced by various factors, including precipitation patterns, temperature variations, and human activities such as agriculture and urbanization.
4. Pollution from agricultural runoff, industrial discharges, and urban development can severely impact the quality of surface water, affecting its usability for drinking and recreation.
5. Surface water interacts closely with groundwater systems; changes in surface water levels can influence groundwater recharge and discharge processes.

Review Questions

• How does surface water interact with other components of the hydrologic cycle?
  • Surface water interacts with other components of the hydrologic cycle through processes such as evaporation, where water from lakes and rivers turns into vapor and enters the atmosphere. This vapor can later condense and fall as precipitation, replenishing surface water bodies. Additionally, surface runoff feeds into rivers and lakes, helping maintain their levels while also affecting groundwater recharge when it infiltrates the soil.
• Evaluate the impact of human activities on the quality and availability of surface water resources.
  • Human activities like agriculture, industrial processes, and urban development significantly impact surface water quality and availability. For instance, agricultural runoff can introduce fertilizers and pesticides into nearby rivers and lakes, leading to eutrophication and harmful algal blooms. Urbanization can increase impervious surfaces, resulting in higher runoff rates that carry pollutants into surface waters. These effects can compromise the ecosystem services provided by surface water and diminish its usability for drinking and recreation.
• Assess the implications of climate change on surface water availability and distribution.
  • Climate change has profound implications for surface water availability and distribution. As temperatures rise, evaporation rates increase, potentially reducing the amount of water in lakes and rivers. Altered precipitation patterns may lead to more intense rainfall events in some regions while causing droughts in others, impacting watershed health and water supply. These changes can disrupt natural habitats, affect agricultural productivity, and strain freshwater resources for human consumption, requiring adaptive management strategies to ensure sustainability.

Related terms

Evaporation: The process through which water changes from a liquid to a vapor, allowing it to enter the atmosphere and continue the water cycle.

Watershed:

An area of land that drains all the streams and rainfall to a common outlet, such as a river or lake, playing a crucial role in managing surface water resources.

Runoff:

Water that flows over the ground surface rather than being absorbed into the soil, contributing to surface water bodies and affecting water quality.