## 4 Use Case  
The approach described in Section 3 has been evaluated using the data from a water supply company in the Mediterranean region of Valencia (Valencian Community, Spain) that manages all processes related to the complete water cycle: catchment, drinking water treatment, transport and distribution for human consumption with full health guarantees.  
Currently, the water crisis is already a reality in many Mediterranean countries, threatening their economic growth and the livelihoods of their peoples. The thought is that the problems will only accelerate. Given international forecasts, multiple thumbscrews are operating on these vulnerable fresh water resources and problems will accelerate. The driving forces are strong: population growth and urbanization; tourism and industrialization; globalization; and climate variability and change, decreasing precipitation and increasing the frequency of droughts [43].  
The Mediterranean is home to 60% of the world's population classed as living in _water poverty_, less than 1000 m\({}^{3}\) of water available per capita per year. Nearly 20 million Mediterranean people have no direct access to drinking water, especially in the rural areas of the south and east. This growing water scarcity and the uncertainties which climate change may bring only reinforce the need to adapt both water policies and land planning policies that impact water management [43].  
In this context, our case study is based on the Mediterranean country of Spain, since is one of the most inhabited communities in Spain. Currently, it has about 5 million inhabitants and is the fourth most populated community in Spain. Explicitly, the data are from the Valencian Community of the period from 2008 to 2014. In addition, the data have been enriched with external repositories in order to add contextual information.  
With respect to water consumption in the cities of the Valencian Community, 476 cubic hectometres (hm\({}^{3}\)) of water were approximately supplied to the urban water supply networks in 2014. Approximately, 25% of this water volume (94 hm\({}^{3}\)) was unregistered water originated by: (a) physical problems in the supply network (leaks, breaks and breakdowns in the network), and (b) measurement problems (measurement errors and frauds carried out by customers). The remaining 75% (382 \(\mathrm{hm}^{3}\)) corresponds to the registered water, i.e., measured on the users' meters [44]. In addition, we have studied water consumption in Spanish households during the analysed years (2008-2014). It is important to highlight that the Valencian Community, although it is not the most populated Spanish region, is the region of Spain that had the highest average water consumption with a value of 164.43 L per inhabitant per day during the studied period.  
Taking into account these data, the aim of our work is to achieve a sustainable management of natural water resources (minimising, for example, unregistered water caused by physical problems in the supply network as it involves a large volume of water that is annually wasted). To this end, in our use case, we will analyse the impact of the different measures or available data (such as leaks or breaks in the network and the number of inhabitants) and their relationship with water consumption with the purpose of reducing it.  
For instance, decision makers and users might be interested in information about the water leaks in the city of Alicante in 2014 or the possible correlation between population and water consumption in the city of Valencia during a specific period of time. However, sometimes the information provided by water companies is not structured (e.g., textual information), or partially registered and inaccurate, making the information retrieval process more difficult.  
In the next three subsections, we will explain the proposed ontology, the application of our proposal to the use case, and the conclusions extracted from the experimentation.