<p>Digital water and energy maps allow fast information retrieval, big data analysis and resources demand prediction for real time responses in 5-G networks. A regulatory systems framework is needed to enable and promote integrated actions grounded on map-based feedback information, to facilitate resources movements and knowledge transfer for water and energy security. At the same time, the proposed regulatory system needs to safeguard national security and personal privacy when general public and the private sectors have access to big databases.</p><p>The Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in China is an initiative on regional economic development involving nine mainland cities and two Special Administrative Regions (SARs). As central policies cannot be efficiently executed in the whole regions, institutional fragmentation could be a prominent barrier to achieve regional water and energy optimum rather than individual city maxima for the water and energy nexus.</p><p>In this study, we propose a systems regulatory framework that integrates natural, urban and social systems across multiple scales in which the relevant laws, policies, decisions and actions are supported by digital maps. On a planning scale, our new regulatory system based on spatial map information promotes optimum uses of natural capitals and ecosystem services (ES). For linking different urban spatial processes on different scales, satellite images and Local Climate Zone (LCZ) maps are used to describe natural environment and urban characteristics from 200km to 10km resolutions for supporting land-use planning laws and estimating regional development carrying capacity to mitigate water and energy insecurity.</p><p>On an operational scale, smart meters and remote sensor systems provide real time water and energy information from a fast developing 5-G network for the proposed digital maps. Forecasted energy and water demands from the digital maps can be used for regional or local environment regulation reinforcement. Proposed spatial maps also improve transboundary collaboration by providing visualisation of legal targets and emission limits. Through digital maps, key agencies and sectors will have a capacity to share transboundary knowledge, information and responsibility, to foster smooth system flows in terms of culture, economy, policy and technology, by active participations and decentralized actions.</p><p>On an evaluation scale, open map information increases the transparency of legal targets and pollution limits. By rapid information retrieval and big data analysis from digital maps, regulators can assess the performance of water and energy security practices.</p><p>In summary, the proposed framework based on LCZ maps for the GBA can be applied to other rapidly developing regions with emerging 5-G networks. The integrated regulatory framework also guides water and energy security practices and transfer central policies to local actions by rapid information retrieval, big data analysis and prediction of demand for real time responses based on digital water and energy maps.</p><p></p><p></p><p></p><p></p><p></p>