IFLA Advisory Circle Article: Design challenges in the Urban Green Infrastructure Network

AC Header thin

IFLA Advisory Circle Article: Design challenges in the Urban Green Infrastructure Network

Author: Christina Del Pozo, member of IFLA Advisory Circle.

Landscape architects have the holistic vision needed to approach and solve the global problems we are facing nowadays. We understand the processes that shape the land. We can plan and design the landscape as a network of spaces and places to perform ecological and societal functions, including its aesthetics values and cultural identity.This network, now referred to as Green Infrastructure (GI), is a spatial structure that offers benefits to people and can also serve as a framework to define urban shape and growth. It performs as a system and connects the natural and built environments. Well planned and designed, GI can make a major contribution to the adaptation of cities to climate change impacts, to the conservation and enhancement of biodiversity, to improve environmental quality, to promote social cohesion and enhance local landscape character.

fig.1.raingarden vitoria-spain-1

Adaptation measures can be introduced in the design of open spaces to contribute to urban resiliency. One of the expected climate impacts will be the increase in frequency and intensity of rainfalls, which can be mitigated with a water sensitive urban design. The water cycle is integrated in the design, via Suds (Sustainable urban drainage systems), the reduction of impervious surfaces and grass, increase in permeable pavements and vegetation that improves soil structure.

Adaptation measures that try to alleviate the water scarcity should consider vegetation with low water requirements, native vegetation, the reduction of turf surfaces and the use of efficient irrigation systems.

Extreme situations of heat, cold, humidity, strong winds and sun exposure should be avoided. With the foreseeable temperature increase, it will be necessary to create cooler microclimates in order to improve environmental comfort in cities. Therefore, design strategies for the reduction of urban temperatures when tackling open spaces and public realm projects will be crucial. The increase of shaded areas with a dense urban green cover and the introduction of artificial elements (pergolas, textiles) should be considered.

High temperatures can also be reduced by incorporating water elements that produce a refreshing effect, both physical and psychological; using materials that reflect heat as much as possible, channelling breezes and designing large areas with shrub species and irrigation to promote evapotranspiration.

The GI network should enhance connectivity to facilitate the movement of species, allocate areas that will require protection and buffering and create and restore wildlife habitats.

It can also help reduce the pressures on green spaces from urban sprawl and guide the processes of urban change. Quoting Sieverts (a German architect and urban planner born in 1934), in his book Cities without Cities: An interpretation of the Zwischenstadt, he describes the new form of global urbanity as an urbanised landscape. He considers landscape is the glue of this “in-between” city, and that it is the degree of penetration with open spaces and landscape and the density of development that determine its specific character.

Even though the benefits of this strategic planning approach are well known, we still need to overcome some barriers such as design challenges. Examples of these are ensuring the adaptability of   Green Infrastructure to changes in climate and use, as well as encouraging a coordinated vision for the various land managers whose maintenance teams have diverse objectives. However, I believe that landscape architects should take the lead on the integration of Green Infrastructure into policies at all scales, national regional and local.

fig.3.Pavimento permeable

fig.2.rain garden vitoria-spainThis article comes from Christina Del Pozo, a member of IFLA Advisory Circle.

IFLA’s Advisory circle members are experts in a range of topics.  Christina passes on her advice to IFLA members on Green Infrastructure