Surface water

Definition

Surface water refers to any body of water that is found on the Earth's surface, such as rivers, lakes, ponds, and reservoirs. It plays a crucial role in the hydrologic cycle by providing a direct source for evaporation, which contributes to atmospheric moisture, and is also essential for replenishing groundwater supplies through processes like infiltration.

5 Must Know Facts For Your Next Test

1. Surface water accounts for only about 0.3% of the Earth's total water supply, but it is vital for ecosystems and human activities.
2. Rivers are a significant type of surface water that play a key role in transporting nutrients and sediments across landscapes.
3. Lakes can act as reservoirs for storing surface water, supporting biodiversity and providing habitats for various aquatic species.
4. Seasonal changes can significantly impact the availability of surface water due to variations in precipitation and evaporation rates.
5. Human activities such as agriculture and urbanization can affect surface water quality and availability through pollution and increased water demand.

Review Questions

• How does surface water contribute to the hydrologic cycle, and what processes are involved?
  • Surface water plays a critical role in the hydrologic cycle by serving as a primary source for evaporation. When sunlight heats up bodies of surface water like lakes and rivers, it causes water to evaporate into the atmosphere. This vapor then contributes to cloud formation and ultimately leads to precipitation. Additionally, surface water can infiltrate into the ground, replenishing groundwater supplies, thus linking both components of the hydrologic cycle.
• What are some impacts of seasonal changes on surface water availability and quality?
  • Seasonal changes can greatly influence both the availability and quality of surface water. For example, during spring and early summer, increased rainfall can lead to higher river flows and lake levels. Conversely, summer heat can result in increased evaporation rates, lowering surface water levels. These fluctuations can also affect water quality; for instance, warmer temperatures may promote algal blooms, which can harm aquatic ecosystems and make the water unsafe for human use.
• Evaluate the consequences of human activities on surface water systems and their implications for sustainability.
  • Human activities such as urbanization, agriculture, and industrial development significantly impact surface water systems. Urbanization often leads to increased runoff due to impervious surfaces like roads, which can cause flooding and reduce natural filtration. Agricultural practices may introduce fertilizers and pesticides into nearby rivers and lakes, affecting water quality. The implications for sustainability are profound; if these practices continue unchecked, they could lead to severe water shortages, loss of biodiversity, and degradation of aquatic ecosystems, highlighting the need for sustainable management strategies.

Related terms

Groundwater: Water that is stored beneath the Earth's surface in soil pores and rock formations, which can be replenished by surface water through infiltration.

Evaporation: The process by which water changes from a liquid to a vapor, occurring directly from surface water bodies into the atmosphere.

Watershed: An area of land where all precipitation collects and drains off into a common outlet, often leading to rivers or lakes.