Netherlands

But most people don’t consciously gravitate to urban parks to get cooler. They enjoy the recreational, aesthetic, and psychological benefits of green spaces too. Nevertheless, Klemm points to research that shows a preference for green spaces with shade and water features.

Design Guidelines Needed: Theory and Practice Meet

For landscape architects and urban planners to obtain the best combination of benefits from urban green infrastructure, design guidelines are needed.

Klemm sees the development of these guidelines as consisting of a process in which real-life contexts are used to evaluate urban green infrastructure impacts on microclimate. This information feeds into evidence-based design guidelines which can be implemented in practice, evaluated, and further refined.

Green Infrastructure Guidelines: Using What we Know

By compiling accepted knowledge and information, Klemm and her research team formulated a simple set of design guidelines for urban green infrastructure. The guidelines covered cities as a whole, parks, and streets. A team of landscape architects and a team of Master’s Degree students were each supplied with the guidelines, and their responses were recorded.

In general, both groups saw the importance of considering microclimate in landscape design – not only in determining site conditions, but in altering them for greater comfort.

However, landscape architecture professionals expressed concern about implementing the guidelines for use at city and street level while approving the guidelines generated for use at park level. Participants felt that the city level guidelines, which include expanding green spaces to form interconnected corridors, were self-evident, but could be difficult to implement.

Naturally, thermal adaptation isn’t just about keeping cool. The guidelines for parks recommends a diversity of shaded, half-shaded and sunny areas with multiple potential functions and park benches allowing park visitors to choose how much sun they want to get.

At street level, tree selection and placement play a vital role. Deciduous trees allow sun through in the winter, and the researchers recommend species with wide canopies for streets subject to high sun exposure. But thermal perception also matters, and the guide suggests using greenery at different heights or levels to improve it – a measure that may be difficult to implement on many existing urban streets.

Where to From Here?

According to Klemm, climate responsive green infrastructure design isn’t getting the attention it should. She argues that global warming may soon make it a priority, even in mild climates like that of the Netherlands.

Microclimate enjoys some attention as a design consideration, but improved consciousness could lead to more focused implementation of the design guidelines, a greater volume of scientific evidence, and a refined set of green infrastructure guidelines for the cities of tomorrow.