Urban parks are natural spaces within our cities that provide numerous benefits and that require an enormous amount of resources for their conservation and management. For example, more than 10 years ago maintaining Retiro Park in Madrid cost more than 5 million euros per year. But beyond their cost, urban parks are necessary spaces that provide numerous benefits, including their potential to revitalize the economy, their effects on public health, their obvious environmental value as natural refuges in urban zones, their important and growing social value as recreational and community spaces, and finally their educational function with regards to the natural environment.
Managing the wooded areas of urban parks is especially complicated, due to the soil conditions in which many of our urban trees are planted, the amount and impact of urban infrastructure like sidewalks, houses, or highways, and the challenges in determining the state of the trees without resorting to destructive or highly invasive techniques that could negatively affect their health. In the past few years, there have been multiple accidents in Spanish cities because of trees or branches falling that were in bad condition and had not been properly maintained.
That is why utilizing methods that allow us to determine the conditions of urban wooded areas in a city or park can be of great use.
Satellite remote sensing and drones with multispectral cameras help define parameters and indices that can signal the vigor and health of vegetation. This, combined with the growing precision of some satellites, can reach a pixel size of up to 72 cm, allowing us to have a very complete idea of the state of each one of the trees. With this pixel precision, a tree with a canopy of 50 square meters (radius of 4 meters) would have more than 100 pixels inside. In other words, we could evaluate each small part of the canopy to evaluate the state of the entire tree.
This innovative technology is a device for public and private agents who want to explore new ways of acquiring information to improve their actions and activities.