Link to external tool
Use in decision framework
|Assess adaptation options|
3Di is an interactive model for water management and can map out water flows and the effects of flooding, heavy precipitation and drought, both for the current situation – for example during heavy rainfall – and for climatological scenarios in urban and rural environments. For example, a ‘water scan’ can be carried out using the 3Di area model, allowing the vulnerable areas in the city during extreme precipitation to be mapped out accurately. In addition, 3Di shows the effects of interventions in water and spatial planning on water management. The area models are suitable for a broad target group, varying from water specialists, spatial planners, operational managers and communications advisers through to disaster coordinators.
The area models are generated automatically from the object database and the raster database by a 3Di specialist. Every water manager has source data and the corresponding software for managing data about waterways, sewers and civil engineering objects. When an area model is produced, data standards are used along with standard management software. The data that is required for the area model is read into an ‘object database’ and a ‘raster database’.
A 3Di area model can consist of one or several model layers, namely a:
- raster terrain layer (for flooding and precipitation)
- raster subsoil layer (for soil moisture content and groundwater) – The soil properties are specified per sub-grid and the soil moisture content is calculated per sub-grid.
- 1D open water network layer (for the canal system) – A profile can be given for the canals showing resistance and bed height
- 1D sewer network layer (for the sewer system) – Underground constructions can be described in detail using storage height functions
Precipitation and evaporation can be input as well as flooding. In principle, the precipitation uses weather radar images, but it is also possible to add precipitation from weather stations.
A 3Di area model can be used for a desktop study, as an interactive tool in workshops and as part of a system for fire brigade support or high water prediction. Alternatives can be input immediately during working sessions and the effects calculated. The users can play interactively with 3Di. Effects of possible interventions can be visualised in next to no time, providing maximum support for the evaluations. The high level of detail also means that laymen can recognise the situation and ‘non-specialist’ users are also able to come up with ideas and try them out. Additionally, the advanced GIS environment gives specialists the capability to make much larger numbers of changes behind the scenes.
The area models are generated automatically from the object database and the raster database by a 3Di specialist. The object database and the area models are stored in the cloud. All the variants of an area model are managed automatically in the cloud and it is possible to retrieve older variants.
When a calculation is to be carried out, the user has a 3Di web interface for choosing an area model and a scenario. The user can start up a calculation with the ‘play’ button and follow the calculation on the map as it progresses. During the calculation, the user can retrieve information and make changes. These modification may relate to the spatial planning or the water and wastewater systems and civil engineering structures.
3Di area models can quite literally map out water flows and the effects of flooding, heavy precipitation and drought, both for the current situation – for example during heavy rainfall – and for climatological scenarios in urban and rural environments.
3Di is a highly successful co-operative venture, consisting of Nelen & Schuurmans, Detares and TU Delft, who have joined efforts in the foundation called Stichting 3Di. This foundation manages 3Di and is working on further development of 3Di.
Conditions for use
The formats and the structure of the input and output files of the calculation core are fully open and accessible; the interface has been published. An area model is developed as a one-off by the 3Di Foundation and placed in the cloud. This means that the quality and problem-free functioning can be guaranteed in the cloud. Users can then make whatever changes they want using open GIS models.
Various practical case studies have been carried out over the last few years in international context.