SWIM - Surface Water Integrated Modeling

SWIM is an open-source software package for static modeling and prediction of surface water and urban flooding based on analysis of terrain topography. It is developed and maintained by the Applied Computational Science research group at SINTEF Digital.

SWIM consists of a collection of algorithms for analysing terrain, identifying watershed boundaries, and providing a better understanding of how water accumulates and moves through the landscape. This is valuable for various purposes, such as water resource management, flood modeling, and environmental planning.

Our algorithms originate from work on CO2 storage and are based on an assumption of infinitesimal flow. These so-called spill-point analyses were later modified to model flooding in urban areas. Spill-point analyses are highly computationally efficient compared to tools based on numerical simulation. This makes it easy to work interactively and test out various scenarios and measures. SWIM offers some unique functionality, such as simplified infiltration models (both permeable and impermeable surfaces) and the calculation of time series that models how water accumulates or drains over time, without having to resort to computationally intensive numerical time-stepping approaches.

Functionality

SWIM is a set of tools that is intended to provide a flexible foundation for further development. Current functionality includes:

• Static surface models
  • Calculation of catchment areas, waterways, and hierarchical networks of intermittent streams, ponds and lakes
  • Accumulation areas for water, topological network of ponds, and how they connect and merge together
  • Permanent water volumes such as rivers, lakes, and seas
• Dynamic analysis
  • Terrain response to precipitation events and infiltration over time
  • Routing of water as ponds overflow
• Terrain characteristics and infrastructure
  • Buildings, obstacles, drainage, and measures
  • Simplified infiltration model that supports both permeable and impermeable surfaces
• Basic IO and visualization routines

System of lakes and rivers identified in the watershed analysis.

Learn more

The best way to get introduced to SWIM is to have a look at the provided examples:

• The Urban landscape example provides an introduction to key SWIM functionality applied to a real dataset of a district in central Oslo.
• The Simple synthetic example uses an extremely simplified surface to explain and demonstrate some key concepts.
• The Handling flat areas example is a small example to show how large, flat water bodies can be identified and kept separate from the analysis.

Note on running the examples

The scripts found in the example directory have their own Project.toml file. This environment should be activated before trying to run the examples. Here is a step-by-step guide to how you can make the exampls run:

1. In your terminal, go to the example directory and start up Julia.
2. Go to the package mode by typing ] and activate the current directory by running activate .
3. Still in the package mode, run: dev ..
4. Now you should be able to run the examples.

Note:

• It is recommended that you run the exmaples block-by-block in an IDE, rather than having them run through in one go by includeing them, in order to properly see all generated figures before they are updated/changed.
• Regarding step (3) in the list above: The SWIM package is not currently registered in the Julia General Registry, and as a consequence, it does not automatically download and install when needed. To tell julia to use the locally downloaded repo, this line will point to the right place.

For inquiries, you can get in touch with the contact person listed at https://www.sintef.no/en/software/swim/.

License information

Copyright (c) 2024 SINTEF Digital

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.