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The city of Florence relies on Smart irrigation

 the IoT has profoundly changed the way green spaces are irrigated. At a time when the world is affected by the cycles of drought and from time to time by lockdown, the town councils are seriously looking to employ new technologies that would enable them to develop invigorating green spaces, save on water and supervise remotely the tasks that previously required travel to the site.

 

In the green spaces department, it is the smart irrigation solutions that have shown an upswing in fortunes this year. These innovative solutions allow for significant savings to be made on water, controlling irrigation remotely and managing the parks, gardens or the public roads, in their entirety.

That is the case with the town of Florence, in Tuscany, which has adopted a smart irrigation solution and obtained significant results these last two years.

And even though the new technologies are taking over our daily lives and our towns, and we hear more and more about the Smart City and the IoT (Internet of Things), it is important to remember how these technologies have significantly transformed the traditional irrigation solutions, even those with centralised control.

 

Smart irrigation : The IoT and Artificial intelligence (AI) are there to serve the city and the environment

The concept of a smart city is mainly based on the development of the IoT (Internet of Things) and AI (Artificial Intelligence) technologies, i.e. the capacity to capture information in the field through connected sensors and process this information to produce the knowledge that can be applied retroactively to the physical world.

These devices use different types of sensors:

- Internet-connected (web-enabled) soil moisture sensors;

- Web-enabled solenoid valves;

- Web-enabled water meters;

- Web-enabled weather stations;

Once they are installed, the moisture sensors will transfer the soil moisture measurements, several times a day, in order to deduce the soil water reserve available to the plants. This will enable the user to control the irrigation more precisely and remotely trigger the opening and closing of the valves via solenoid valve controllers. It is this automatic control system that will enable the user to make significant savings on water.

In certain cases it can also be linked to the weather data (particularly rainfall predictions) to avoid irrigating when it is raining, this being something that happens all too often.

Lastly, installing a web-enabled water meter or connecting the existing one by using a scanning head will allow for the automatic detection of hidden leaks in the system or the identification of broken irrigation devices.

 

Smart irrigation: A massive change in the decision-making METHOD, RESULTING IN spectacular savings on water

The decision-making procedures used in older generations of irrigation equipment, even centrally-controlled ones, were based on evapotranspiration models, using the historical data taken over several decades. The focus on water consumption and climate change has meant that these models have been pushed to their limits.

The introduction of soil moisture sensors turned the decision-making process upside down, as it allowed irrigation to ‘match’ the real needs of the plants, taking into account the vagaries of the weather (extreme heat or rains) and the level of uniformity: differences in exposure, wind… all these elements that were difficult to take into consideration within a specific model are considered when measuring the soil moisture available to the plant: this being the easiest way to arrive at a good decision.

By automating the irrigation cycles according to the plant water requirements any unnecessary irrigation will be avoided.  This, therefore, results in a saving on water; the city of Florence, for example, managed to achieve a 55% reduction in the water applied to the gardens equipped with smart irrigation systems.

 

The city of Florence (Tuscany) sets out its ambition of becoming a European smart city with a project relating to the irrigation of green spaces

The smart irrigation initiative of the city of Florence began in December 2018 with the support of European funding. The aim of this project was to fulfil 4 main objectives: reducing potable water consumption; automatically identifying hidden leaks or vandalism-related damage; not irrigating while it is raining; and finally, time-saving for the gardeners.

The project was undertaken jointly by the green spaces department and the DSI (Directorate of Information Systems), taking into account the decision-making criteria acquired from their past experiences.

The compatibility of the new equipment with the existing irrigation devices was crucial for considering the solution on a large scale and at an acceptable cost; in fact, the city has 8 million square metres of green spaces.

The officials responsible for green spaces have opted for a solution capable of making savings automatically without the need for human intervention, having access to an application available in Italian, which is extremely simple and easy-to-use in the field.

Capitalizing on its previous experience in the deployments of IoT devices, the local authorities have opted to go for a solution that allows for the proper supervision of the fleet of sensors and which guarantees a battery life of several years as well as reducing the number of site visits required.

Finally, in its endeavour to become a Smart City, the DIS (Directorate of Information Systems) has steered the local authority towards a solution that is open and interoperable: the choice of a non-proprietary solution was necessary in order to be able to retrieve the data and incorporate it into their information system. The person in charge of the IT project added: “We wanted to deploy a standard infrastructure that can be used for other purposes; we didn’t want to be locked in to any one technology or a single manufacturer”.

Over time, the application has been enhanced with a reference system for the green space assets and a logbook of activities. The agents will then have at their disposal a tree inventory with typologies, characteristics and their conditions, all located on a map. The teams in Florence will now have a complete tool for the use and development of their green spaces.

 

“Technological innovation helps us in combatting the wastage of natural resources and makes the public services more efficient”

Cecilia del Re, City Councillor for the Environment and Technological Innovation

According to the deputy mayor for the environment and technological innovation, the use of a smart irrigation device is a real asset for the local authority and its agents: “Technological innovation helps us combat the wastage of natural resources and makes the public services more efficient and sustainable for the management of the city’s public parks. The government’s undertaking to make our city smarter will, therefore, also focus on the vegetation and making the irrigation systems more efficient. This not only means less water consumption and less pollution caused by maintenance vehicles travelling to the gardens, but also an improvement in the quality of the upkeep due to a more personalised irrigation programme, specific to each particular site. These are important objectives for a city that has 8 million square metres of green spaces, increasing, over the last five years alone, by 285 thousand square metres”,  declared Cecilia Del Re.

The winning combination of being environmentally-friendly and having a committed team resulted in Florence being given the Green Smart City award by the European Commission.

Ultimately, this smart irrigation tool has opened up a broader perspective for the city, thanks to the deployment of the LoRaWAN network which, in the future, will allow for the new Wi-Fi enabled sensors to be integrated into other types of usage.

 

 

But why will the use of IoT technologies change irrigation so extensively?

The IoT is based on the concept of standardised and interoperable technologies, which represents a departure from the first generations of closed and proprietary centrally-controlled irrigation systems.

The emergence of the Internet and web services had already enabled the standardisation of data transfer. The IoT allows for this standardisation to be extended to equipment used in the field. This standardisation represents the basic difference between the first generations of centrally-controlled irrigation systems and the smart irrigation models.

This need for interoperability has changed commercial behaviour. Nowadays, it is no longer a question of selling a proprietary system that will lock the customer into a certain technology while waiting for its update. It is now a matter of selling, apart from the product itself, something that encompasses the whole potential total value offered by the interoperability feature. This allows the DSI (Directorate of Information Systems) or the IT department to retrieve the data from the sensors and very easily incorporate it into their own tools. For example, it would be easy to stop the irrigation systems during a festival. The events calendar is connected to the irrigation device; it’s that simple!

 

The underlying interoperability of the IoT increases its practical value

With the IoT, each sensor or solenoid valve controller is directly connected to the Internet, so it is no longer necessary to lay cables. The architecture becomes very simple: no satellite, no repeater or base stations, no servers in the equipment room.

By its very construction, the architecture of the IoT allows for a reduction on all of the costs: purchase, installation and operation.

Claiming that it is environmentally-friendly imposes an obligation of having to fulfil the promise to use frugal (low-energy) technologies with a low carbon footprint.

The LPWan connectivity technologies used for environmental sensors, also called 0G as opposed to 5G, are based on the “small data” strategy. They collect little information but they produce intelligence or know-how, which helps the decision-making process, rather than amassing gigabytes of data.