Chapter 4 Web architecture
Web architecture involves the design and structure of the web-based components that deliver and interact with the data, including servers, interfaces, and protocols, to provide users with access to spatial data through web services. Data architecture (see Chapter 3.2), on the other hand, provides the underlying structure of data organisation, storage and management, ensuring it is accessible, interoperable, and efficiently handled.
When connecting a spatial data infrastructure (SDI) to a web interface, several technical considerations should be kept in mind for ensuring seamless integration and optimal performance.
The architecture must support a range of web services compliant with Open Geospatial Consortium (OGC) specifications, such as Web Mapping Service (WMS)64, Web Feature Service (WFS)65 and Catalogue Service (CSW)66 to assure interoperability and seamless data exchange. The system should also incorporate robust metadata management practices to maintain comprehensive, up-to-date metadata records.
Additionally, optimising server performance, minimising load times, and employing scalable cloud-based solutions can enhance user experience and accommodate growing data volumes. Automated processes for metadata synchronisation and data updates can reduce errors and streamline management. Security measures, such as SSL/TLS encryption and secure authentication, must be in place to protect data during transmission and prevent unauthorised access.
Finally, responsive design principles should be applied to support the web interface to be accessible and functional across different devices and screen sizes, including desktops, tablets, and smartphones.
The subsections below present further explanation about these topics.
4.1 Connectivity and interoperability
From an Information Technology perspective, the connectivity functionality provided by SDI systems relies on the interoperability of geospatial data services delivered through web services compliant with Open Geospatial Consortium (OGC) specifications. A minimum set of web services that an SDI should publish includes:
Web Mapping Services (WMS): A webservice for requesting a map of an area. Technically it is an image with associated coordinates structured in such a way that it can be displayed by compatible software.
Web Feature Service (WFS): A webservice for requesting data that is associated with a feature on a map, e.g., a point. WFS services also offer the ability to request that underlying data be delivered in one of a number of available formats.
Catalogue Service for the Web (CSW): A web service for exposing a catalogue of geospatial records in XML, so that the catalogue information can be read and processed by other services. An example is a central catalogue that harvests the CSWs of other catalogues and collates the records together to publish a single unified catalogue.
4.2 Enhancing performance and scalability – dealing with growing data volumes {ch4-2}
Optimising server performance, minimising load times, and employing scalable cloud-based solutions are critical for the web architecture of SDIs to support efficient data access and user satisfaction.
Server performance
Server performance refers to the efficiency and speed at which a server processes requests and delivers content to users, ensuring a seamless and responsive experience for web portal users.
This performance can be enhanced through the following:
Load balancing to distribute incoming traffic evenly across multiple servers, thereby preventing any single server from becoming a bottleneck.
Implementing caching strategies, such as server-side and client-side caching, can significantly reduce load times by storing frequently accessed data temporarily.
Using high-performance databases and optimising database queries support efficient data retrieval and storage operations.
Monitoring server performance in real-time and conducting regular maintenance and updates can proactively address potential issues.
Minimal load times
Minimal load times describe the rapid loading of web pages and content, which is necessary for a swift and efficient user experience with minimal delay.
Minimal load times can be achieved by the following actions:
Optimising website code, such as minimising JavaScript, Cascading Style Sheets (CSS), and HTML files, and leveraging asynchronous loading techniques to make sure that essential content is prioritised.
Image optimization, including using the correct formats and compression techniques, helps reduce file sizes without compromising quality. For SDIs, this means faster loading times for map layers and imagery, improving the overall user experience when interacting with geospatial data. Efficient image formats like WebP or optimised JPEGs can significantly decrease bandwidth usage. Employing techniques such as adaptive image serving, which delivers images tailored to the user's device and screen resolution, supports users to receive the best possible performance regardless of their hardware or network conditions.
Implementation of Content Delivery Networks (CDNs) which distribute content across multiple servers worldwide, reducing latency and speeding up data delivery to users in different locations.
Enabling server-side caching can store frequently requested data closer to the user, further reducing load times.
Scalable cloud services
Scalable cloud services refer to cloud-based web portal solutions that can dynamically adjust computing resources to meet varying demands. Employing such solutions for SDI web architecture supports maintaining consistent performance even during peak usage periods and supports long-term flexibility and efficiency of the SDI.
Cloud platforms such as Amazon Web Services (AWS)67, Microsoft Azure68 and Google Cloud Platform69 offer Infrastructure as a Service (IaaS) and Platform as a Service (PaaS) option that allow SDIs to dynamically allocate resources based on real-time demand, ensuring optimal performance during peak usage without over-provisioning during quieter periods. These solutions provide robust data storage, high availability, and disaster recovery capabilities, which are essential for maintaining continuous access to geospatial data.
Additionally, cloud-based architectures support automated scaling and load balancing, distributing traffic and computational loads effectively to prevent bottlenecks. They also facilitate easy integration of advanced technologies, such as machine learning and big data analytics, which can enhance the functionality and value of the SDI.
©Metamoreworks/Shutterstock.com (*)
4.3 Data security considerations for SDI web architecture
Data security is crucial in the web architecture of an SDI to protect sensitive geospatial information from unauthorised access, breaches, and potential misuse. Robust security measures maintain user trust and compliance with data protection regulations, which is essential for the credibility and long-term sustainability of the SDI.
The web architecture for an SDI must balance the needs of a public web portal and secure access for authorised users.
Public web portal
The public web portal is designed to provide broad access to general geospatial data, making it user-friendly and highly accessible. This includes an intuitive interface with features such as map viewers, search functions, and data visualisation tools that allow users to easily discover, view, and download available datasets. The architecture employs responsive design to provide for optimal performance across various devices, from desktops to mobile phones. Load balancing, caching, and Content Delivery Networks (CDNs) are used to support fast loading times and high availability, even during peak usage periods (see above for Minimal load times). Security measures like Secure Sockets Layer/Transport Layer Security (SSL/TLS) encryption protect data transmission, ensuring that user interactions remain secure (see SSL/TLS encryption details below).
The general steps for the implementation of a web portal are suggested as follows:
Define requirements and objectives for the public-facing web portal, considering user needs and project goals.
Select a suitable web development framework and technology stack based on project requirements and team expertise.
Design user interface wireframes and prototypes to visualise the layout and navigation of the web portal.
Develop front-end and back-end components, including HTML/CSS templates, JavaScript functionalities, and server-side logic.
Integrate with backend data sources and APIs to populate the web portal with dynamic content and interactive features.
Implement security measures (SSL encryption, user authentication) to protect sensitive data and user privacy.
Conduct usability testing and accessibility audits to assure the web portal is intuitive, responsive, and compliant with accessibility standards.
Authorised access
For authorised access, the architecture incorporates additional layers of security and functionality. User authentication makes sure that only verified users can access the system by requiring credentials such as passwords, biometric data, or multi-factor authentication. This step prevents unauthorised access and verifies that users are who they claim to be.
Authorization protocols then determine what an authenticated user is permitted to do within the system, providing different levels of access based on the user's role or permissions. The architecture can include robust data management tools that enable authorised users to upload, edit, and manage datasets within the SDI. Secure APIs and web services compliant with OGC standards support authorised machine-to-machine communications to be consistent and reliable. These measures help protect sensitive information from being accessed, altered, or stolen by unauthorised individuals.
In the context of SDIs, implementing user authentication is particularly important when dealing with critical geospatial information that could be sensitive or confidential. Ensuring that only authorised personnel can access and manipulate this data prevents data breaches and supports compliance with data protection regulations (Box 20).
For more details about data security please see Chapter 5.
Box 20: Security measures for the web architecture of the Spatial Data Infrastructure
Additional security measures for the web architecture of an SDI include:
SSL/TLS encryption: SSL/TLS encryption protects data transmission by establishing a secure channel between the user’s browser and the web server. This encryption assures that all data exchanged is encoded and unreadable to unauthorised parties, safeguarding sensitive information from interception or tampering during transmission. In the context of SDIs, SSL/TLS encryption is essential not only for protecting user credentials and personal data but also for securing the transmission of potentially sensitive geospatial information. By implementing these protocols, an SDI can assure that user interactions, whether they involve viewing maps, downloading datasets or accessing restricted data, are conducted securely.
Access Logging and Monitoring: By maintaining detailed logs of who accessed what data and when, these measures facilitate auditing, help detect suspicious behaviour and enable timely responses to potential security incidents. This supports accountability and helps identifying and addressing security threats or breaches.
Backup and Disaster Recovery Plans: These plans involve regular, automated backups of all critical data and system configurations, along with a well-defined strategy for restoring operations in the event of hardware failures, cyber-attacks, or other disasters. By implementing robust backup and recovery solutions, SDIs can minimise downtime, protect against data loss, and maintain continuity of service.
4.4 Web portal accessibility
User-friendliness is crucial for a public-facing web interface, as this supports users of all technical backgrounds to be able to easily access, navigate, and utilize geospatial data and services. A clear, intuitive design facilitates learning, encourages broader engagement, and enhances the usability of the SDI. This is especially important for non-expert users, who may need geospatial data for decision-making, research, or community projects but lack specialized knowledge. A user-friendly interface supports inclusivity, maximizes the SDI's impact, and supports its goal of making spatial data accessible for everyone.
4.4.1 Ease and speed of user access
A web portal should cater to a wide range of users, from seasoned professionals to newcomers to MSP. Creating a user-friendly and accessible web portal is crucial for maximising its effectiveness.
Focus on speed and efficiency
Users should encounter fast-loading pages. Optimising the website's code, image sizes, and server performance is essential for delivering a quick and responsive user experience.
The web portal's layout and navigation should be clear and intuitive, allowing users to quickly and easily find the information they need without getting lost in complex menus or functionalities.
With the increasing use of mobile devices, ensuring optimal functionality on smartphones and tablets is essential. A responsive design that adapts the layout and content for various screen sizes guarantees accessibility for all users.
Inclusivity as a priority
The web portal should adhere to established web accessibility standards. This includes features like keyboard navigation, screen reader compatibility, and clear colour contrast for users with visual impairments.
Catering to a diverse user base might require offering the web interface in multiple languages. This allows broader participation and knowledge sharing within the MSP community.
Providing clear instructions, tutorials, and FAQs can be invaluable for users unfamiliar with the web portal's functionalities.
4.4.2 Data visualisation through web portal
To make data easily understandable and actionable, the choice of data visualisation tools is critical. Dynamic visualisation tools allow users to explore data in multiple ways. They offer benefits such as:
User Interaction: Users can zoom in/out, filter datasets, and adjust visualisation parameters, enabling in-depth exploration.
Layered Data Overlays: Dynamic tools can display multiple datasets simultaneously, revealing hidden patterns and correlations.
Dynamic Updates: Users can see data updates reflected in real-time, ensuring access to the latest information.
These tools might require a steeper learning curve for users unfamiliar with interactive elements. There could also be issues related to technical requirements: dynamic tools may require a faster internet connection and higher processing power for optimal performance.
SeaSketch (Box 21) is an example for web architecture delivering data access through an accessible web portal with up-to-date visualisation options, providing support for conservation projects as well as citizen information requests.
Case Study
Box 21: SeaSketch for the Blue Azores (Portugal)
Contributed by Will McClintock and Adriano Quintela
The Blue Azores program is a partnership between the Government of the Azores, Oceano Azul Foundation and the Waitt Institute, focused on the conservation and sustainable use of the Azorean Sea. Marine Spatial Planning, conservation, sustainable fisheries, ocean literacy, sustainable blue bioeconomy and science are at the centre of the Blue Azores, supporting Portugal and the Azores to achieve international and national objectives set by the United Nations Sustainable Development Goals (SDGs) of the 2030 Agenda for Sustainable Development, Convention on Biological Diversity, International Union for the Conservation of Nature, European Biodiversity Strategy 2030 and the National Strategy for the Sea 2030.
The Blue Azores is a dedication to providing stakeholders with:
The best readily available scientific information,
Tools for collaboratively designing science- and policy-based zoning scenarios,
Fully transparent decision-making process.
SeaSketch is a software service specifically developed to support MSP. The most recent, free and open-source version of SeaSketch was used to create an SDI for the Blue Azores Program that serves as a web platform for:
Uploading, storing and versioning geospatial data, metadata and cartographic styles;
Integrating map services (serving as a ‘data intermediary’) such as those published by the Portuguese Maritime Ordinance Geoportal (https://www.psoem.pt/geoportal-2/);
Visualising and downloading geospatial data;
Sketching and evaluating prospective zoning scenarios based on regional goals and objectives defined by the MSP working group;
Sharing prospective zoning scenarios in map-based forums along with textual justifications and supporting documents;
Gathering new geospatial information on ocean uses and values by way of map-based surveys.
The Blue Azores Spatial Data Infrastructure (SDI) built on the SeaSketch platform represents a comprehensive database on current and potential ocean uses, marine habitats, jurisdictional boundaries, underwater cultural heritage, and biological information (such as the distribution of vulnerable marine ecosystems, fish, mammals and sea turtles). The data were provided by academic, government and non-governmental organisations and will be updated on an as-needed basis.
The SDI administrative dashboard currently includes code-based and graphical user interface (GUI) tools for cartographically styling datasets (i.e., choosing colours, labels, etc.). Recent updates include tools for exporting data layers in a variety of formats including shapefiles, flatgeobuffs, GeoTIFFs, and GeoJSON. And, in 2026, a new set of GUI tools for configuring analytical reports will dramatically expand the usability of SeaSketch for planning purposes.
This SDI was a crucial tool in the participative process allowing the co-creation of Marine Protected Area (MPA) solutions maximizing conservation objectives and minimizing the impact on activities (e.g. fishing effort). As a result of this process, the Azores Government approved Regional Legislative Decree No. 14/2024/A.
This revision of the Azores Marine Park includes oceanic MPAs that safeguard 30% (498,000 Km²) around the Azores’ sea (EEZ), with half of this area completely closed to any extractive activities, becoming the largest network of MPAs in North Atlantic.
Figure 28: The Blue Azores SDI is built on the SeaSketch platform and hosts data from academic, government and non-government sources.
©SeaSketch (*)
Figure 29: Marine Protected Areas of the Azores. The areas inside the EEZ were developed by stakeholders using the SeaSketch platform.
© Blue Azores Program (*)
For more information please see:
Blue Azores Initiative:
https://www.blueazores.org/aboutblueazoresBlue Azores SDI:
https://www.seasketch.org/blueazores
4.4.3 Data download
When considering options for data downloads from an SDI, it is important to think of the needs of both human users and machine users (or the interoperability/API use case).
Human users’ expectations include the following aspects:
An easy to navigate web portal, usually with a map viewer.
The ability to visualise data of interest on the portal's map viewer.
The capability to query a dataset by region using the portal map viewer, as well as to download the data for that region.
The option to download complete datasets.
Access to data in widely used formats, avoiding proprietary formats that require obscure software to view.
Direct downloads from the portal to their desktop, without having to navigate away from the SDI portal after using its discovery tools.
For machine-to-machine communication, the expectations are similar but with additional emphasis on consistency and persistence. Web services that deliver data must guarantee that calls requesting a specific subset in a defined format remain consistent and repeatable over time, without requiring human intervention. To achieve this, datasets must have persistent identifiers, and the parameters passed with the web service request to query the dataset must be consistent and well-documented.
The web services used for the SDI portal's human interface should also serve machine-to-machine communication. This approach:
Reduces the workload for the IT team maintaining the portal.
Facilitates a consistent data publishing method.
Data throughput refers to the amount of data that can be transmitted, processed or accessed within a given time, usually measured in units like bits, bytes or megabytes per second. It reflects how efficiently the SDI handles data flow between servers, services and users.↩︎