Impervious Surfaces

Definition

Impervious surfaces are man-made structures that do not allow water to penetrate through them, leading to increased runoff during rainfall events. Common examples include roads, parking lots, and rooftops. These surfaces contribute to various urbanization challenges, such as flooding, water quality degradation, and loss of natural habitats.

5 Must Know Facts For Your Next Test

1. Impervious surfaces can significantly increase the volume and speed of stormwater runoff, which can overwhelm drainage systems and lead to flooding.
2. They are associated with water quality issues since they prevent natural filtration processes, allowing pollutants to wash directly into waterways.
3. The presence of impervious surfaces is linked to urban heat islands, which can raise local temperatures and exacerbate energy demand for cooling.
4. Mitigating the impacts of impervious surfaces often involves implementing green infrastructure solutions like permeable pavements or rain gardens.
5. Urban planning strategies that reduce impervious surfaces can help restore natural hydrology and improve overall ecosystem health.

Review Questions

• How do impervious surfaces affect stormwater management in urban areas?
  • Impervious surfaces play a significant role in stormwater management as they increase the volume and speed of runoff during rainfall. Since these surfaces do not allow water to infiltrate into the ground, it can overwhelm drainage systems, leading to flooding. Effective stormwater management strategies must account for the presence of impervious surfaces by incorporating solutions that slow down or capture runoff before it reaches drainage systems.
• Discuss the environmental implications of the increase in impervious surfaces in urban development.
  • The increase in impervious surfaces during urban development has several environmental implications. It leads to heightened runoff that carries pollutants into water bodies, resulting in degraded water quality. Additionally, these surfaces contribute to the urban heat island effect, where cities become significantly warmer than surrounding areas, affecting local climates and energy consumption. Addressing these impacts requires innovative urban design that incorporates green spaces and sustainable practices.
• Evaluate the effectiveness of green infrastructure solutions in mitigating the negative impacts of impervious surfaces on urban ecosystems.
  • Green infrastructure solutions have proven effective in mitigating the negative impacts of impervious surfaces on urban ecosystems by enhancing water quality and reducing runoff. Techniques such as permeable pavements, rain gardens, and bioswales allow water to infiltrate and be absorbed by the ground rather than being channeled away. This not only helps manage stormwater more effectively but also restores natural hydrology, reduces flooding risks, improves air quality, and supports biodiversity in urban areas.

Related terms

Stormwater Management: The process of controlling the quantity and quality of stormwater runoff to minimize its impact on the environment and infrastructure.

Urban Heat Island Effect: A phenomenon where urban areas experience higher temperatures than their rural surroundings due to human activities and extensive impervious surfaces.

Green Infrastructure: A sustainable approach to managing water resources that uses vegetation, soils, and natural processes to enhance water quality and reduce runoff.