Geomorphology. The study of Earth’s form. Of landscapes and landforms and the processes that create them. It could be the most interesting field of science that you’ve never heard of.
Geomorphologists look at how the world’s landscapes are shaped by the actions of water, ice, wind, life, and geological processes such as volcanic eruptions. They study mountains, coasts, and deserts. No landscape is off limits. Some geomorphologists even study landscapes on other planets.There are urban geomorphologists too. They look at the interactions between landscape processes and urban development, and this is where geomorphology is relevant to green roofs.
As an example, imagine a pristine hillslope during a big storm. Much of the rain is being intercepted by the natural vegetation. The rain that makes it to the ground is seeping into the soil, although some of it is running over the surface, maybe in gullies. The flow of water in the creek at the bottom of the hill is slowly increasing, and sediment concentrations in the creek are changing. These are the types of processes that are studied by a geomorphologist, who will also look at the origin and evolution of the hillslope itself.
Now imagine the same hillslope covered in buildings and roads. It’s an entirely different story. When rain falls on this urbanized hillslope, it is almost certain to land on a hard surface, and it is likely to reach the creek very quickly. Even if the creek itself has escaped being modified as part of urban development, it will not escape the effects of its urban surroundings. It will change, and a geomorphologist would study this.
And now imagine that every building on the urbanized hillslope has a green roof. The green roofs, by design, will capture rainwater that otherwise would have reached the creek. Urban development altered the processes of the landscape, but green roofs can help guide them back towards the natural state.
A geomorphologist can help to evaluate where green roofs are most beneficial, or how their design can be optimized. A geomorphologist can give green roofs context, by considering their place and role in the landscape. While geomorphology often overlaps with other fields, such as hydrology, a geomorphologist could see things that other green roof professionals might miss.
We are going to be thinking about how we can use geomorphology to create better green roofs and better cities. Because geomorphologists should Do it on the Roof too.
Paul Richards, Do it on the Roof