Introduction
LCZ 2 is a dense mix of mid-rise buildings (3-9 stories) with narrow streets. Traditional designs in many climates already provide a degree of mutual shading. Heat Problem: High. Dense construction materials and reduced airflow trap significant heat.
Example Locations:
Temperate: Paris (France), Barcelona (Spain), Rome (Italy)
Tropical: Old San Juan (Puerto Rico), Hanoi (Vietnam), Mumbai (India)
Arid: Marrakech (Morocco), Cairo (Egypt), Jerusalem
Continental: Old Montreal (Canada), Prague (Czech Republic), Vienna (Austria)
Mitigation Measures for LCZ 2
1. Urban Vegetation (Street Trees)
Evaluation & Reasoning: Provides direct shade and cools the air through evapotranspiration. Tree canopies can reduce surface temperatures of asphalt and concrete by over 20°C.
Climate Suitability:
Temperate/Continental: Excellent. Using deciduous trees is a smart seasonal strategy, as their leafy canopy provides summer shade while their bare branches in winter allow sunlight to pass through for warmth.
Tropical: Highly effective for year-round shade.
Arid: Effective but less viable due to high water demand. Requires drought-resistant native species to be sustainable.
2. Green & Cool Roofs
Evaluation & Reasoning: Highly effective due to the large, often flat, roof areas common in this LCZ. The principles of insulation (green roofs) and reflectivity (cool roofs) apply strongly here.
Climate Suitability:
Universal: Green roofs offer year-round insulation benefits. Cool roofs are most impactful in climates with hot, sunny summers, with the minor "winter penalty" being a consideration in colder zones.
3. Water Features
Evaluation & Reasoning: Fountains and misters provide localized cooling through evaporation. As water evaporates, it draws energy (heat) from the surrounding air, lowering its temperature. This also improves psychological comfort.
Climate Suitability:
Arid/Temperate/Continental: Highly effective in dry heat where the air can readily absorb more water vapor. Water scarcity in arid zones makes this a lower-viability option unless using recycled water.
Tropical: Less effective for cooling because the high ambient humidity slows down evaporation. However, they still provide strong aesthetic and recreational benefits.