Learn about the most effective strategies, including vegetated roofs and white cement roof pavers, for reducing heat island effect and managing rainwater runoff to prepare for the USGBC LEED Green Associate certification exam.
Table of Contents
Question
Which of the following strategies contributes to reducing heat island effect and managing rainwater runoff?
A. A vegetated roof
B. White cement roof pavers
C. A rainwater collection system
D. Shading structures that include photovoltaic panels
Answer
A. A vegetated roof
Explanation
A vegetated roof, also known as a green roof, is a roof that is partially or completely covered with vegetation and a growing medium, such as soil or compost. A vegetated roof can help reduce the heat island effect and manage rainwater runoff by providing the following benefits:
It reduces the surface temperature of the roof by reflecting solar radiation and cooling the air through evapotranspiration, which is the process of plants releasing water vapor from their leaves. This can lower the ambient temperature of the surrounding area and improve thermal comfort for occupants and pedestrians.
It reduces the amount and speed of stormwater runoff by retaining and filtering rainwater in the vegetation and growing medium. This can prevent flooding, erosion, and pollution of downstream water bodies, as well as reduce the demand for potable water for irrigation or other purposes.
It enhances the biodiversity and habitat of the urban environment by providing a space for plants, animals, insects, and microorganisms to thrive. This can improve the ecological health and resilience of the ecosystem and provide aesthetic and recreational benefits for humans.
Other strategies that can contribute to reducing the heat island effect and managing rainwater runoff are:
White cement roof pavers: These are tiles made of concrete that have a high solar reflectance index (SRI), which measures how well a surface reflects solar radiation. White cement roof pavers can help reduce the surface temperature of the roof by reflecting more solar radiation than darker or less reflective materials. However, they do not provide any benefits for stormwater management, as they are impervious surfaces that do not retain or filter rainwater.
A rainwater collection system: This is a system that captures and stores rainwater from roofs or other surfaces for reuse. A rainwater collection system can help reduce stormwater runoff by diverting rainwater from landfills or incinerators to other destinations, such as irrigation, toilet flushing, or cooling. However, it does not provide any benefits for reducing the heat island effect, as it does not affect the surface temperature of the roof or the surrounding air.
Shading structures that include photovoltaic panels: These are structures that provide shade for roofs or other surfaces by blocking direct sunlight. Shading structures that include photovoltaic panels can help reduce the heat island effect by lowering the surface temperature of the roof or the shaded area. They can also help generate renewable energy from solar power, which can reduce greenhouse gas emissions and energy costs. However, they do not provide any benefits for stormwater management, as they do not retain or filter rainwater.
A vegetated roof, also known as a green roof, is a key strategy that contributes to both reducing the heat island effect and managing rainwater runoff:
- Heat Island Effect Reduction: Vegetated roofs help mitigate the heat island effect in urban areas by absorbing less heat and reflecting more sunlight compared to traditional dark-colored roofs. The vegetation and growing medium act as a natural insulation layer, reducing the amount of heat absorbed and re-emitted by the building.
- Rainwater Runoff Management: Green roofs can retain and slow down the flow of rainwater, reducing the volume and velocity of runoff. The vegetation and growing medium absorb and filter the rainwater, decreasing the burden on storm water systems and improving water quality. Retained water is then released back into the atmosphere through evapotranspiration.
While white cement roof pavers (B) can help reduce the heat island effect by reflecting more sunlight, they do not significantly contribute to managing rainwater runoff. A rainwater collection system (C) can help manage runoff but does not directly address the heat island effect. Shading structures with photovoltaic panels (D) provide renewable energy and some shading but have a limited impact on heat island effect and rainwater management compared to vegetated roofs.
In summary, vegetated roofs offer a comprehensive solution for both reducing the heat island effect and managing rainwater runoff, making them the most appropriate answer to the question.
USGBC LEED Green Associate certification exam practice question and answer (Q&A) dump with detail explanation and reference available free, helpful to pass the USGBC LEED Green Associate exam and earn USGBC LEED Green Associate certification.