## 2 Regional Seismic Risk: Assessment and Mitigation through a Simplified Procedure
### Optimal Budget Allocation  
In the budgeting phase, it is necessary to know the results of simulations such as those herein presented. First of all, it is necessary to identify the \"minimum\" and \"maximum\" values. The minimum total cost (Figure 3; \"Min Tot Cost\" in Equation (4)) is that which is required to solve the most urgent problems, which are the demolition and reconstruction of the highest risk buildings (i.e., those with \(\chi_{\text{i}}\leq 0.2\)). The maximum total cost corresponds to the cost needed to provide all buildings with a vulnerability index greater than or equal to the allowable value 0.8 (Figure 3; \"Max Tot Cost\" in Equation (4)). The budget to be invested should not exceed the maximum value unless it is decided to increase the allowable value of the capacity / demand ratio beyond 0.8 (case 3 in Figure 3). Once the investment has been established, the optimal allocation has to be found that leads to the most effective reduction of the overall seismic risk. If the available budget is below the minimum value, the decision is unambiguous, that is demolishing and rebuilding the largest number of buildings with \(\chi_{\text{i}}\leq 0.2\), until the budget is exhausted, giving them priority according to their own \(\chi_{\text{i}}\) value. If the available budget belongs to the range between minimum and maximum values (case 2 in Figure 3), it is necessary to identify the best solution through the optimization of the budget allocation. The best solution is the set of interventions for each building that allow minimizing of the overall post-intervention seismic risk (SRpost-int) while the total retrofitting costs (Ctot) remain within the available budget (optimal solution  
Figure 3: Total retrofitting cost versus total post-intervention seismic risk [19]. in Figure 3). The above logic for sharing the budget and deciding the optimal intervention for each building is summarized in Equation (4). \[\textit{if }\rightarrow\text{Available Budget}\leq\text{Min Tot Cost}\] \[\textit{then }\rightarrow\text{Demolition and Reconstruction of the largest number of}\] \[\text{buildings with }\chi_{i}\leq 0.2,\text{ until the budget is exhausted} \tag{4}\]  
\[\textit{if }\rightarrow\text{Min Tot Cost}\leq\text{Available Budget}\leq\text{Max Tot Cost}\] \[\textit{then }\rightarrow\text{best solution: }\textit{minSR}_{\text{post-int}}\text{ subject to }\text{C}_{\text{tot}}\leq\text{Available budget}\]  
A Technological Platform to Manage Regional Seismic Risk Accounting for Available Economic Resources  
To facilitate the spread of the practical use of the procedure described above for seismic risk mitigation on a territorial scale, it is crucial to have the support of a valid operational IT tool, with a simple and effective interface for the user. Within a European research project called GRISIS (Risk Management and Safety of Infrastructures at a regional scale), a technological platform has been used to assess and manage natural and anthropic risks at regional scale within a unique tool. The prototype release of such a tool focuses on the territorial area of the Campania region in southern Italy and involves seismic, hydrogeological, environmental risks as well as that associated with the potential collapse of human infrastructures like telecommunication networks. The GRISIS backend data management combines technologies and features to integrate and make available IoT, geo-referred data, reprocessed data and products. The backend integrates data services and catalogues such as GeoServer, THREDDS Data Server and ERDDAP, which also implement system layers for machine-to-machine interoperability according to OGC standards. On top of this backend private-cloud infrastructure, a webGIS portal provides a gateway to data, metadata and data products. It provides digital maps, with panning, zooming and selecting features allowing users to view and interact with data products, with full metadata including links to retrieve further documentation and references.