In this article, I will describe a simple and fast demand based Landuse Allocation model.
All code is open source and you can see it on the Allocation Model GitHub repository including tutorial videos.
- Free and Open Source
- Written in Python and uses Shapely and RTree libraries.
- Compatible with Geodesign Hub and the Geodesign Hub API
Geodesign Hub enables collaborative planning and we have used it in the various workshops and projects. In some of our workshops, we have participants from different counties or municipalities working together. Counties and planners are acting in their self interests in the context of a larger region. In such a scenario, designers and planners optimize for maximum commerce, industry and housing in their jurisdiction to increase taxes, revenues etc. However, a locally optimized design may not necessarily be the in the best interest of the region.
So it is important to have a broader regional outlook while taking into account the design preferences of local authories. This co-ordination between regional and local bodies in meeting a design objective is a important issue. We use technology and landuse allocation to empower the designers building plans and help in resolving design conflicts when it comes to allocating “urban” landuses.
The model logic is detailed in the GitHub repository and there is a YouTube video describing how to use it. Bascially using the evaluation maps and prioritizing the allocation systems the model allocates landuse to ensure that no two systems will compete for the same parcel. So if a parcel is occupied by commerce, it will automatically be disqualified for use by any other system (low density housing) for example.
Following details the output after running the model.
Gridded evaluation and detail
The evaluation map is a Shapefile / GeoJSON that shows suitablily of a particular place for commerce, industry or housing. Green means suitable and Red means unsuitable. These act as one of the imputs to the model.
Designed features (retrived via Geodesign Hub API)
The map above on a gray boundaries file shows the designed features. These are aspriations of designerers for their jurisdiction.
Allocated using the Model and assigning targets.
Based on the evaluations, the designed features and targets (set as in the model configuration), the model allocated geometries till the targets are achieved ensuring that the most profitable system is allocated first and there are no allocation conflicts.
Designed and Allocated one on top of other
The speed of this model depends on the evaluation maps and the grid size but for a large study area ~500 square kilometers with a 8 hectare grid and a modern computer it takes about 11 seconds.
This is because of the extensive use of RTree and other optimization techniques. This model is blazing fast and can be used in conjunction with larger more complicated models that take a much longer time. This type of quick and dirty landuse allocation is most useful when there are issues around model licensing, avialability of hardware etc. We use it in a number of our studies and it is avialable for use with Geodesign Hub.
As you can see, designers were optimistic in their designs. There is only so much of industry, commmerce and housing a region can sustain so even tough they designed a lot of area, only a small percentage of it was allocated, especially for the low density housing system.
The outputs of this model can be submitted back as diagrams to Geodesign Hub for addition in to the designs. We use this model extensively in our workshops to have a more accurate landuse patterns.
Geodesign Hub’s API enables models to be integrated this way where data is taken out, analyzed and data can be submitted back as impacts, evaluations or new diagrams. We maintain a list of compatible tools on our plugins page. If you are interested in making your tools and models Geodesign compatible, please reach out.