Here’s an article on quantifying the urban cool island. Which, as you might expect, is the opposite of the urban heat island.

Quantifying the cool island effects of urban green spaces using remote sensing Data

Urban Heat Island (UHI) leads to increased energy consumption, aggravated pollution and threatened health of citizens. Urban green spaces mitigate UHI effects, however, it is still unclear how the green space characteristics and its surrounding environment affects the green space cool island (GCI). In this study, land surface temperature (LST) and land cover types within the outmost ring road of Shanghai, China were obtained from Landsat 8 data and high-resolution Google Earth data. The GCI effects were defined in three aspects: GCI range (GR), amplitude of temperature drop (TA) and temperature gradient (TG). Pearson correlation analysis was processed to get the relationship between the aspects and impact factors. The results indicated that the GCI principle could be explained by the thermal conduct theory. The efficient methods to decrease LST of green spaces include increasing green space area while staying below the threshold, adding complexity of green space shape, decreasing impervious surfaces and enlarging the area of water bodies. For the surrounding environment of the green spaces, increasing vegetation and water body fractions or decreasing impervious surfaces will help to strengthen GCI effects. The findings can help urban planners to understand GCI formation and design cool green spaces to mitigate UHI effects.

This is a subject where I’m out of my depth in terms of formal training, but certainly interested. There are at least two ways you can try to combat the urban heat island effect, which occurs when pavement and other man-made surfaces absorb heat during the day and release it slowly at night (and during the day). The first is to use light-colored materials to reflect sunlight back into space. Using white roof materials whenever practical seems like a no-brainer. Maybe we don’t want snow white paving materials everywhere at the ground level, because that could be displeasing and even painful to the eye, but certainly we could dispense with the asphalt. Even if asphalt didn’t absorb heat, it would still be a hideous, toxic, short-lived material. It’s better to use concrete or brick or stone or almost anything else – it may cost more up front but it will last longer and just generally make our urban areas better. Materials that are permeable to rain water are also available so let’s consider those where they make sense.

The other way is to maximize the use of soil and vegetated surfaces. Soil and vegetated surfaces also absorb heat, I think, but then dissipate much of it again through evaporation and transpiration. Then there is the simple process of tree canopy create shade at ground level (which I imagine satellite studies like the one above may have trouble picking up on). In very dry climates, this may not be practical because to state the obvious, you need water to have evaporation. In very, very wet climates, it might make sense to store rainwater and intentionally spray it on your paved surfaces to cool them down. This is assuming you want to get rid of the heat and water – if you are in a place where water is scarce and precious, you might not want to do that, and you might even want to think twice about having a lot of vegetated surface. Or maybe that is not the right place for large numbers of people to live. Unless you can create more or less a closed-loop water system, in which case it might be a good place, thinking in terms of ecological footprint and preparing for humanity’s possible future in space.