Soil moisture
Within Measure your City soil moisture was measured in order to see how long periods of rain or drought affect the moisture status of the soil. Due to climate change extended periods of drought and heavy rainfall are increasingly expected in the (near) future. The better the soil is capable of buffering these extremes, the less the negative effects will be on for example plant growth, or damage to buildings and infrastructure in the city. By investigating how moisture in different soils changes due to rainfall, drought and the type of plants growing on it, we hope to take more targeted measures for climate adaptation, such as enhancing the soil composition or choosing plants that are more drought-tolerant.
Soil moisture sensors were developed by citizen science collective Meet je Stad (Measure your City). Measure your City was started in 2015 by inhabitants of the City of Amersfoort, with the goal of measuring climate related indicators. To be able to do so, collaboration was sought with the City of Amersfoort (COA), the local Water Authority and the University of Applied Sciences of Amsterdam. For the first three years the initiative focused on measuring temperature and humidity. Importantly, citizens develop their own research questions, analyze the data together with professionals and discuss potential implications. By doing so, the collective uses citizen science to spread knowledge on both technology
and climate change in the most grass-roots manner possible.
Within the SCOREwater project, Measure your City was asked to expand measurements with soil moisture measurements and additional temperature and humidity sensors.
An important note here is that Measure your City develops their own sensors, has developed their own data platform and uses its own gateways purchased from the Things Network. As a result, much effort is put into constructing sensors that are reliable, low-maintenance and accurate. The latter is important
for the City of Amersfoort as well, which intends to not only work on shared knowledge and understanding, but also use the data for policy making. To do so the data has to be reliable. By deploying both these sensors and purchasing company-built sensors, we can compare the data to assess how reliable the Measure your City sensors are.
Figure 1. Soil moisture sensor from Meet je Stad
Data collection
The data collected in the Amersfoort case is transmitted from the sensors to the online environment using two LoRaWAN gateways. Data is sent to this SCOREwater platform once every three hours. Once the data is available on the platform, the data will be harmonized using the FIWARE GreenSpaceRecord FIWARE model. This model contains a harmonized description of the conditions recorded on a particular area or point inside a greenspace (flower bed, garden, etc.), like soil temperature or soil moisture. The Measure your city soil moisture sensors measure soil moisture using conductivity.
About Meet je Stad (Measure your City)
Measure your City is a citizen science initiative. The process of science does not take place at a university with buildings, professors and a rat race just to get something published, but simply with people like you.
Anyone who is curious and wants to find out things will find a nice place at Measure your City. That can be anything: finding out how a certain sensor works, how to make a graph from measurement data, what the influence of climate is on... you name it.
