On 24 March 2021, Adif unveiled the new Geographic Information System (GIS) of the Mediterranean Corridor to celebrate the European Year of Railway. The need to develop a GIS arose in response to requests received by the Commissioner’s Office from institutional, economic and social actors: an official, accessible and user friendly, but at the same time technically and graphically detailed means of consultation.

There are interesting and pioneering examples of GIS applications to trans-European corridors, such as the European Commission’s TENtec interactive map of the 9 trans-European corridors or the CIS (Corridor Information System) of the Rhine-Alpine Corridor. However, neither case manages to combine the precision and quantity of information, the speed of consultation and the ease of use that today’s information society demands. For this reason, Adif has emphasised that the Mediterranean Corridor GIS should set four fundamental objectives: providing up-to-date information on its development; displaying its complexity, identifying all the connection nodes; showing its cross-border and European scope; and visualising the work of the Office and the monitoring of the works. The materialisation of these objectives in the form of this interactive portal has attracted attention in the EU, where the tool has been received with interest. Its excellent reception, which exceeded 10,000 visits in the first month, has prompted Adif to plan the development of a GIS for the Atlantic Corridor as well.

Future scheme of Mediterranean Corridor (Map Viewer).

In order to achieve the aforementioned objectives, a specific working methodology has been developed and articulated in several phases under the direction of the Office of the Mediterranean Corridor. Firstly, it has been necessary to design ad hoc databases to catalogue and process the information related to the Mediterranean Corridor: the technical, socio-economic and geographical aspects of the railway infrastructure, urban nodes, ports and terminals, among others, have been structured and codified in an integrated and coherent manner. This has been very important in order to achieve a geospatial architecture that is both flexible, i.e. allowing periodic reviews, and at the same time rigid, in the sense that no structural modifications are needed and that it is well adapted to other European corridors or other transport networks.

Secondly, all the necessary data and cartographic bases have been collected. This step has relied upon the collaboration of many institutions and companies. Adif’s role in providing geospatial information and very specific data on the railway infrastructure and freight operations, and Ineco’s role in numerous works, studies and projects of the Mediterranean Corridor, both stand out. SNCF Réseau and the Occitania Region were involved in the profiling of the cross-border sector and the French sections. Much data has also been collected from the websites of port authorities, intermodal terminals and private companies websites.

The viewer has a base map to consult all the planned sections under construction and in service and a statistical map with dynamic graphs that summarise the most relevant technical and socio-economic aspects

Thirdly, mapping has been carried out to provide the databases with spatial information. The real challenge has been to harmonise the sectioning of the railway network and the nodes in order to make the sections implemented in the Geographic Information Systems of Adif (IdeADIF) and the European Commission (TENtec) compatible and at the same time coherent with the planning of the works and ongoing studies.

As a result, the network is made up of almost 700 sections between the Network of General Interest and the accesses to terminals and ports, represented in four situations: sections currently in service; in execution; in the study and construction project phase; and, finally, future sections, i.e., when all the actions in progress have been completed.

Nodes, on the other hand, total more than 270 elements. Overall, more than 1,000 elements have been processed, each with its associated geometries and information, with a total of 45,000 attributes. The amount of information to be processed is considerable and continuous revisions (last phase) have been necessary in order to achieve a very high level of accuracy and detail.

In order to show how the Corridor fits in at local and regional level, the layers of the metropolitan and suburban lines of the main urban centres have been incorporated, as well as the major transport networks at ‘Euro-Mediterranean’ level: the route of the European Mediterranean Corridor (to the north), the Trans-Maghreb Corridor (to the south), the maritime connection between Palma de Mallorca and Barcelona/Valencia (to the east) and lastly, Adif’s railway network (to the west).

Finally, a set of socio-economic and environmental indicators have been incorporated in order to understand the Mediterranean Corridor as an axis of territorial structuring, a lever for a more sustainable, resilient and better connected territory. This data will be updated on a regular basis, in line with the progress of the works and ongoing studies. After the data had been validated by Adif, a map viewer was developed in Esri environment that is highly innovative in terms of its structure, content and visualisation. It is available in two different modes: a base map that allows users to consult the information mentioned above, and a statistical map with dynamic graphics that summarise the most relevant technical and socio-economic aspects.

The viewer is hosted on the Hub-GIS of the Office of the Spanish Government Commissioner for the Mediterranean Corridor, where it is possible to consult additional documentation on the Office (reports, annual reports, photos of works in progress, infographics, etc.) and links to related websites. The Hub-GIS is accessible to the public from Adif’s main website and the following link. A searchable user guide has been produced to make it easier to consult and use the viewer.

Using a practical example, it is possible to consult the current status of the mixed-use line between the French border and Barcelona, the type of electrification (25kv), the maximum axle load permitted (22.5t), the gradients in the north and south directions, the total length of the section, etc. We could also visualise the works in progress on the Castellbisbal-Martorell section (mixed gauge installation), known as the ‘Gateway to Europe’ due to its strategic importance for the entire Mediterranean Corridor. The viewer also allows us to visualise the accesses now under construction to the SEAT-Martorell factory, or the remodelling of the Ford factory in Valencia, the new access branches to the ports of Castellón and Sagunto, as well as the dozens of freight terminals and intermodal centres.

The future situation shows what the Mediterranean Corridor will look like once completed and fully interoperable

After reviewing the number of trains handled at a specific terminal (e.g. San Roque freight, on the Algeciras-Bobadilla section), a web link redirects to the functional diagram in Adif’s catalogue of logistics facilities. If, on the other hand, we are interested in knowing where the planned route for the new Murcia-Almería line runs, the corresponding layer would be activated, informing us that the Los Arejos-Vera section has a finished platform, while works are already underway on the adjacent sections. The satellite base map shows the exact location of the project. Finally, the future situation shows how the corridor will look once it is finished, fully interoperable and with passenger stations, freight terminals and urban nodes connected in an intermodal system. In order to understand the Corridor in terms of a territorial project, it is possible to activate some of the economic indicators included in the viewer, such as population per municipality, income per capita at municipal level, tonnes of goods unloaded per province or the level of PM10 and Nitrogen Dioxide (NO₂) pollution.

Ineco has been implementing Geographic Information Systems (GIS) for years to respond to the needs of ever more demanding clients in the field of virtual technologies, BIM, Big Data, etc. However, due to its complexity and novelty, this project marks a milestone for the company and for the Office of the Spanish Government Commissioner for the Mediterranean Corridor, which is coordinated by Prof. Josep Vicent Boira.

The collaboration between Ineco and Adif personnel working at the Office is also noteworthy in terms of compiling and reviewing a large volume of data, as well as providing the advice and technical knowledge of their respective railway experts. Meanwhile, UTE TAG-Esteyco has been responsible for the first phase of the processing of technical and cartographic information.

Ineco has been awarded the Special Achievement in GIS (SAG) Award by Esri, a world leader in software for Geographic Information Systems.

The award acknowledges the company’s ground-breaking work in Spain in the development of GIS (Geographic Information System) technology thanks to the integration of the BIM methodology into a GIS environment to develop a virtual 3D model of the future A-76 Ponferrada-Ourense Highway, for the Spanish General Directorate of Roads.

Every year, different projects around the world in different fields are recognised for demonstrating their capacity for innovation and good use of GIS in solving a variety of problems. (More information here).

The EOS project developed by Ineco was chosen as the winner of the 5th edition of the company’s Innova Awards. EOS is a unique piece of software on the market, a comprehensive and efficient tool for the design of flight paths and procedures followed by aircraft to safely take off and land at airports. Its development is the result of collaboration between teams of aeronautical, computer and telecommunications engineers.

It uses spatial geometric calculations, integrated with a GIS developed by NASA and a 3D visual interface, for the calculation of safe flight procedures. It complies with ICAO air navigation regulations and is constantly being developed and updated.

Ineco’s Innova Awards annually recognise in-house projects for their contribution to the development of new knowledge, encouraging innovative initiatives within the company.

In companies, digitisation has been aimed at increasing productivity, which is also the goal of BIM implementation in Spain. However, the recent COVID-19 pandemic has shifted the focus to resilience and maintaining productivity in the face of adverse situations, in short, maintaining the business. This objective is clearly reflected in the pillars of the BIM methodology, which focuses on digital information management –with the reduction of paper-based processes, common data sources and process automation– and collaboration, i.e., the use of collaborative tools, digital exchanges, synchronised access and the use of cloud storage. The new scenarios generated by this pandemic, such as the promotion of remote work (teleworking), the reduction of contact between workers through the establishment of shifts and social distancing, require the increased digitisation of processes in order to ‘work digitally’.

Ineco’s experience in this field has enabled it to ensure the continuity of work and to fulfil its commitments during this period, although it is necessary to continue developing this methodology for its generalisation as a working standard. As part of this process, a body of documentation is being created to contribute to the success of this endeavour through specific manuals, guides, process automation tools, etc. These actions are complemented by the creation of a digital community of practices that will serve as a meeting point for all those interested in the application of the methodology within the company, people from different fields and with different visions that contribute to establishing and prioritising needs.

BIM observatory.

BIM in infrastructure projects

Although BIM, as a methodology or set of processes, does not distinguish
between areas, over the last year Ineco has developed various linear infrastructure projects with BIM as the work methodology. These are very different types of projects, ranging from metro or high-speed lines to roads, and applied to various stages of the life cycle, in line with a methodology that aims to address that whole life cycle. Significant progress has been made during this period in areas where the application of BIM methodology faced the greatest challenges:

• Modelling tools: digital models are generated by these tools, which are beginning to incorporate exchange formats designed for linear infrastructure.
• Standards: the publication of the EN-19650 standard establishes the definitions and information flows in BIM processes and makes it possible to move beyond the stage in which its absence led to the use of rules obtained from international standards.
• Interoperability: the publication of the IFC 4.3 open standards (alignment, bridges, road and rail) is an important step forward in establishing the open exchange standard for infrastructure, eliminating the need to resort to formats developed for construction.

BIM public tendering.

BIM sector distribution.

AWARD GIVEN FOR BIM-GIS INTEGRATION ON A HIGHWAY PROJECT

Some of the more important areas of innovation related to broadening the horizons of the application of this methodology are those involving integration with GIS, which recently received the Special Achievement in GIS (SAG) Award given by Esri, a world leader in software for Geographic Information Systems. This work aims to integrate digital information from different sources and technologies into a common environment that encourages and maximises its use, is accessible to as many parties as possible and facilitates decision-making in project implementation.

The award acknowledges the company’s ground-breaking work in Spain in the development of GIS technology thanks to the integration of the BIM methodology into a GIS environment to develop a virtual 3D model of the future A-76 Ponferrada-Ourense Highway, on the Villamartín section of the Abadía-Requejo stretch for the General Directorate of Roads, part of the Ministry of Transport, Mobility and Urban Agenda (MITMA).

BIM-GIS display of the A-76 highway.

The Special Achievement in GIS Awards are international awards given to organisations around the world that Esri Inc. uses to show its appreciation for the use of its technology in addressing some of the world’s most important challenges. Every year, different projects around the world in different fields are recognised for demonstrating their capacity for innovation and good use of GIS in solving new problems.

3 NOTABLE projects

A technical solution for a light metro. This is an international project designed as a technical solution for the building design of a light metro, just over 2 kilometres long, to be connected to an existing external line. The design comprises a 2 km tunnel with three access points, an evacuation tunnel and three underground stations, involving numerous infrastructure disciplines at the same time. The route has very demanding occupation requirements, which means that the coordination and implementation of the infrastructure is especially important.

Metro.

Six teams were involved in the design, generating models belonging to different companies and countries, which is why collaboration between them is also a key aspect, using two common data environments. The BIM uses that were applied included 3D coordination and generation of 2D documentation and quantity take-off.

Three-dimensional models for a highway in Costa Rica. Normally we think of the sequential development of the generation of BIM models in the design stage (project) and their use in subsequent construction and maintenance stages, but in certain cases and under certain circumstances, BIM can be applied in more advanced stages even if it has not been executed in initial stages. This involves digitising the project documentation and converting the drawings into three-dimensional models with all of the associated information. The objective is to use it to monitor the work, simulate construction, obtain quantities for certification and generate ‘as built’ information.

Roads.

This was the case for the San Gerardo-Barranca stretch of the Pan-American Highway in Costa Rica. The project was carried out in the ‘traditional’ way, obtaining the usual documents: design report, annexes, plans, specifications and the bill of quantities. Based on this documentation, Ineco generated the digital models that represent the entire section and all its disciplines: earthworks, pavement, structures, drainage, signs, etc. The digitisation of the project documentation allows the detection of inconsistencies between disciplines. The three-dimensional visualisation alone makes this detection possible. In addition, the linking of construction elements and budget quotes, a number of inconsistencies in quantities and the bill of quantities were detected. A filtering analysis by relevance was then carried out, determining the inconsistencies that were actually relevant for the work stage and which would need to be taken into account.

Currently, we are waiting for the beginning of the works in order to start the monitoring work to be connected with the actual construction plan.

A digital twin to manage a railway construction site. As in the previous case, a high-speed railway section at the access points to Extremadura has been modelled for use in the construction stage, in this case a track assembly site. The objectives are as follows:

• To study the application of the BIM methodology in track installation works.
• To contribute to the improvement of collaboration and communication between different parties.
• To generate a digital twin of the work in order to facilitate management of the work in later stages.
• To monitor the execution of the work in terms of costs and deadlines.

Railways.

The work includes the installation of 55.1 kilometres of double track on ballast, as well as some smaller sections of single track on ballast on a double track platform (around 400 metres) and slab track (around 3.7 kilometres). In this case, the complexity arises from the length of the section involved and the need to identify the basic objects to be introduced in the digital models. Before work began, the corresponding BIM Execution Plan was drawn up, which included the definition of the level of graphic information to be included in the models, taking into account the disciplines involved in a project of this nature (surface treatments, ballast, sleepers, rail, welding and track devices); specific tables were also included for the non-graphic information for each type of element. In the absence of a standardised classification system that includes these type of elements, an ad hoc system was created. The Execution Plan also defined the common data environment, which is essential for sharing information between the site office teams and the design office. Lastly, the quality control model was designed according to the arrangement shown bellow. In total, 38 route and track models were generated, taking into account the section divisions of the project.

Quality control model.

With its 30-year contract to manage six airports in the Northeast Region of Brazil, Aena Internacional has strengthened its leadership in the world and is helping to build new air bridges in a strategic sector vital to the development of the country’s tourism and economy, while at the same time strengthening relations between Spain and Brazil.

Ineco, which provided technical support to Aena Internacional during the entire concession process, will continue to collaborate on both the Operational Readiness and Transfer and subsequent stages, thus strengthening its long history as a technical consultant in Brazil, a country in which the company is carrying out other projects such as supervision of new trains for the São Paulo Commuter network, which is also covered in an article in this issue.

Also in the international sphere, our railway specialisation has taken us to different continents, as reported in the article about the Independent Safety Assessment (ISA) carried out for the improvement of the Panama City Metro and safety studies conducted for the Makkah-Madinah high-speed line in Saudi Arabia.

In Spain, the works on the high-speed line to Galicia also involve building bridges – both figuratively, because of the crucial importance of improving connections with the Region of Galicia, and literally, because of the construction of the large viaducts and other special works that are required, including the ones described in a report in this issue on a section that presents enormous technical complexity.

We also dedicate space to innovation with the RONIN road safety tool and the implementation of a pilot project using the ground-breaking integration of BIM and GIS technology in Spain’s road sector.

Ineco’s commitment to building bridges between training and the exercise of the engineering profession, supporting the development and attraction of talent, has led us to organise, together with the Spanish Institute of Engineering, the first edition of the Awards for Excellence in Engineering Student Internships. These awards are based on performance during a series of theoretical and practical courses that will enhance the training of future engineers and enable them to contribute to increasing the prestige of Spanish engineering.

Similarly, and as part of our unequivocal commitment to the 2030 Agenda, we will be building charitable bridges with volunteer projects that we carry out in our CSR section, in which we highlight three projects already underway in India, South Sudan and Haiti.

The A-76 highway is one of the first road projects in which the BIM (building information modelling) methodology has been applied, a field in which it is not yet very well developed. This has led to an evolution from two- to three-dimensional models with associated information, and working in a collaborative and digital environment that centralises all of project information and makes it possible to overcome existing constraints in terms of information exchange.

The virtual preconstruction of the first of the slip roads of the Villamartín de la Abadía-Requejo section, that of the future A-76 highway connecting to the A-6 highway, was chosen because it is a good representative case. It is a complex slip road in which the lanes of the A-76 separate to connect to the A-6, allowing all possible movements directly. Its design was determined by the topography of the land; additional carriageways connecting to the N-VI and LE-158/15 roads; and the configuration of the A-6 highway’s existing entries and exits. In terms of its most characteristic features, the project has a total length of over 10 kilometres, requires the construction of 11 structures and involves the channelling of the Arroyo de los Valtuilles.

A 3D model was created with geometric and non-geometric information, put together as a puzzle in which the models provided by the disciplines of layout, road surface, land, drainage, structures, affected services and signalling, signs and defences are added using interoperable formats that allow the integration of digital information from a broad ecosystem of tools with which the aforementioned disciplines work.

A ground-breaking project in Spain

In the A-76 project, the BIM world was connected to geographic information systems, for the first time in Spain and virtually the first time in Europe. What both worlds have in common is that they combine geometric elements associated with alphanumeric data (attributes) and, therefore speak a common language. BIM intrinsically focuses on the three-dimensional model of the infrastructure, and GIS, among other aspects, ensures that all other elements are correctly referenced to real coordinates. But the most important thing is that GIS allows the elements to be related to each other, enabling a multitude of analyses to be performed between the data, based on either spatial (spatial topology) and/or semantic relationships.

This provides BIM with an endless number of GIS variables (both 2D and 3D) that it did not have previously and which are essential in all phases. GIS has also contributed to facilitating the understanding of the project and its integration into the environment, without limitations of extension and on multiple scales, in the same three-dimensional scenario. This has been the common framework where all of the elements have fitted together: environmental data, results of hydraulic, noise, fauna, expropriation, land registry studies, etc. The scenario become progressively richer as more data has been integrated, all with spatial reference (coordinates), generating a live and virtual model that is being referred to as the ‘digital twin’.

The BIM methodology has been linked to geographic information systems, resulting in living 3D models that are connected to a physical environment, in what is coming to be referred to as geodesign

Accessible thanks to a 3D GIS viewer

All information is accessible through an online 3D GIS viewer. Customers, technicians, collaborators, contractors or interested users can intuitively consult all of the information of the project by scanning a QR code with a mobile phone, or using the URL and an internet connection via mobile, tablet or computer. The display provides easy and intuitive universal accessibility, making it a new tool for decision making, and also a very powerful communication instrument throughout the different phases of the project.

Through this viewer, BIM and GIS democratise and make the project more accessible in a simple, transparent way, and without the need for training or knowledge of the specific software, which will undoubtedly contribute to its implementation in other projects. This accessibility will result in economic and time savings in the transmission of information to the different parties interested in all phases of the design, as well as decision making.

Especially in public investment projects that are of general interest to the public, social consensus is vital from the early stages in order to streamline future administrative procedures. This new behaviour paradigm is consolidated thanks to technological advances, thus generating new mechanisms for public participation.

This report was made possible thanks to special contributions by Miriam Pinilla and Agustín Roldán, civil engineers; Mirela Vladovic, telecommunications engineer; Laura Martín, geographer y Raquel Veneros, technical architect.

Kaohsiung port, the largest in Taiwan and one of the most important ports in the world in terms of container traffic, is in full expansion with the construction of a new intercontinental container zone, a project that the Ministry of Transport and Communication of Taiwan and the Kaohsiung Port Branch (KPB) began in 2007. To increase its current loading capacity an increase in the size of cranes is necessary to about 150 metres in height in various docks of the port, which is equivalent to a building of 33 floors, such as the Agbar tower in Barcelona. However, the installation of such large cranes would be interfering with the current operations of Kaohsiung international airport, located just two kilometres away, and it would infringe upon the airport’s protection areas. With the objective that the Taiwanese Civil Aviation Authority allows the installation of the cranes, the port authority of Kaohsiung has commissioned a study whose objective is to demonstrate that the cranes will not negatively affect the safety of air operations. This project is being executed jointly by Ineco and the local company MiTAC.

In the context of the project, Ineco has already carried out a series of key activities with regard to evaluating the feasibility of an increase in the height of the cranes. Firstly, Ineco engineers have analysed both the maximum heights that the cranes could reach in each dock of the port without interfering with the instrument flight procedures published (including take-off, approach and landing manoeuvres and flights en route), as well as the modifications that would be necessary in the flight procedures for these to be compatible with the heights of the cranes required by Kaohsiung port authority in each of the port’s docks, thus ensuring the safety of these operations in accordance with the procedure design standards of the International Civil Aviation Organization (ICAO).

To increase the current loading capacity of the Kaohsiung port it is necessary to increase the size of the cranes to about 150 metres in height in various docks of the port, which makes it necessary to modify the instrument flight procedures of the airport

Secondly, given that cranes of such large dimensions can be an obstacle for the correct transmission of electromagnetic signals of the air navigation facilities located in the vicinity, Ineco experts have studied their compatibility with all of the communications, navigation and surveillance systems that support the operations in Kaohsiung airport and in the surrounding air space, with 11 facilities in total being analysed, including instrument landing systems, primary and secondary surveillance radars, distance measuring equipment and communication centres. The examination of communications, navigation and surveillance systems (known as CNS systems) was carried out in terms of coverage and quality of the signal in space (through the study of potential multipath phenomena), with support from specialised radioelectric simulation tools.

Moreover, taking into account the new dimensions of the cranes, it was analysed in which way the obstacle limitation surfaces of Kaohsiung airport, established in Taiwanese regulations, would be infringed and recommendations were provided with respect to marking and lighting needs for the cranes that do so, in accordance with ICAO regulations. Lastly, Ineco provided the relevant recommendations regarding operations of the pilots.

The methodology for executing the previously mentioned analyses was also defined by Ineco, using for this purpose its extensive experience in studies of these kinds both in Spain and in other countries, and adopting the necessary hypotheses in each case, since cranes are mobile objects and since the model intended to be installed was not known.

As a result, the report shows, on one hand, for the 44 docks analysed the maximum achievable height compatible with the current instrument flight procedures, and the modifications necessary in these procedures (increase of the climb gradient in certain departures, modification of the operation minimums in various approaches, etc.) with regard to allowing the installation of cranes with the required height in each of the docks; moreover, with the objective of ensuring compatibility with current and future CNS systems, both the adaptations that must be carried out in the systems, when they are necessary and feasible, and the maximum heights that cranes can achieve to ensure that no adverse effects will occur (when there is no mitigation mechanism of this effect through the adaptation of systems) are depicted; lastly, the infringements of the protection surfaces over the 44 docks are detailed as well as the associated marking and lighting recommendations.

The methodology for executing the analyses was defined by Ineco, using for this purpose its extensive experience in studies of these kinds both in Spain and in other countries, and adopting the necessary hypotheses in each case

For years Ineco has carried out work relating to obstacle limitation surfaces, flight procedures or CNS systems in airports in Spain, Oman, the UAE, Cape Verde, Singapore and Kuwait, among other countries.

In the course of the infrastructure inspection campaigns of the high- speed lines, deficiencies were detected in the drainage systems of some sections. These deficiencies are resolved within normal or intense levels of rainfall through enlargements and improvements of the drainage network, based on a localised supply of resources.

However, as has been demonstrated occasionally, there can be catastrophic levels of rainfall that exceed all forecasts or normal schedules. The magnitude of the rainfall, the gentle slope of the land, the low level of the tracks and the insufficiency of the drainage elements are factors that may result in incidents on the rail platform.

This is the case of the incident that occurred on 2 July 2014 on the Madrid-Alicante high-speed line, at the town of Alpera (Albacete). The intense rainfall in the zone caused a great accumulation of water next to the platform. The flow water dragged away the ballast, leaving the track without support and causing it’s settlement. As a result of this incident, preparations began to commission Ineco with the study to determine the potentially floodable zones in the high-speed lines in operation.

To achieve the improvement of the drainage network, it is necessary to realise a hydrological study using two-dimensional models, through the application of net rainfall (associated with return periods of 100 and 500 years) and the joint analysis of the transversal and longitudinal drainage system.

The models allow us to study the behaviour of the flow in interbasins and plain zones, as well as the height of the sheet of water at any point. The simulations consider the effect of flood abatement upstream of the works and the dam effect of existing downstream obstacles. Furthermore, the flow speed can be verified and zones with risk of erosion can be detected.

The magnitude of the rainfall, the gentle slope of the land, the low level of the tracks and the insufficiency of the drainage elements are factors that may result in incidents on the rail platform

METHODOLOGY

Firstly, information about the layout and the drainage system is compiled to carry out an inventory of the crossing works. The existing inspections and the incidents registered are consulted. A hydrogeomorphological analysis of the track layout is carried out, allowing a selection of the sections to be studied with the two-dimensional models, while they are classified in accordance with their priority.

Next, the Digital Terrain Model (DTM) is prepared, for which the model is linked to the mesh size of 5m (data from the LIDAR flight of the PNOA, National Plan for Aerial Orthophotography) with topography at a scale of 1:1,000 for the trace of the line. Thus, a single DTM with a 2m mesh size is obtained, which incorporates the openings due to large crossing works in the line to be studied and in other nearby infraestructuras.

In parallel, rainfall in each of the sections is obtained from the ‘Maximum daily rainfall in the Spanish Peninsula’ publication of the General Directorate of Roads of the Ministry of Public Works, in 1999. The intensity of the rainfall in accordance with its duration is calculated through the IDF (Intensity-Duration-Frequency) curves of the Spanish Meteorology Agency, AEMET. To obtain net rainfall, we consider, in addition to rain, the land retention with data of the GIS layer of the water flow supplied by the Ministry of Agriculture, Food and the Environment through its CAUMAX project.

The next step is to generate the two-dimensional model with the Infoworks ICM program. The model defines the land through a triangular mesh from the DTM data, using fracture lines that mark the main traces of the platform slopes, zones with a different mesh size (finer around the platform) and polygons with different land roughness. The model also includes other elements, including for example small drainage works, which simulate the flow in a one-dimensional way. Once validated, rain data can be uploaded and simulations in ICM can be perfore.

Sections of the line are classified in accordance with it’s risk, delimiting potentially floodable zones. Thus, plans are made showing the potential flood risk and the results of the study of each axis are documented in a report

RESULTS OF THE TWO-DIMENSIONAL MODELS

Firstly, six rain episodes are simulated corresponding to the return period of 500 years, whose duration is related to the concentration time of the most important basin. Once the simulations have been performed, it is checked whether the platform is affected.

If it is not affected, the process ends and the section would be low-risk. In the contrary case, it would be necessary to simulate the same episodes of rain with the return period of 100 years. If it is affected only for T500, the risk considered is medium. If it is also affected for T100, the risk is high.

According to the foregoing criteria the lines are classified in sections in accordance with it’s risk, delimiting the potentially floodable zones. As such, plans are obtained to show the potential risk of flooding classified by sections of all lines. The results of the study of each axis are expressed in a report. In the four axes together 2,351 km of trace of route was studied and 89 2D models were made, with a total length of 810 km.

Lastly, we propose an action plan for all of the high-risk sections and for the medium-risk sections associated with the latter. We recommend analysing the 2D models, identifying necessary complementary data (photographs and detail topography), inspecting the area on the field, defining appropriate solutions, performing new simulations and, where applicable, drawing up the appropriate construction projects. Furthermore, the rest of the sections with a medium risk must be analysed to assess the need to carry out these actions on them as well.

Moreover, we recomend to identify other high-speed lines that will start operating soon, evaluate the available information on incidents, inventories and inspections, the documentation of as built projects and the availability of the topography (aerial photography track flights).