Steven Braakman
Expert Infra
Impervious Surface Data. Every sealed square metre.
Detailed, continuously updated surface sealing data. Essential for flood risk management, heat stress analysis and spatial planning.
What we monitor
We map and classify every surface type across the Netherlands. Distinguishing between sealed surfaces such as roads, pavements and buildings, open paved surfaces such as gravel and permeable tiles, unsealed terrain such as soil and grass, and water. We detect the current state of surface sealing at high spatial resolution and track how the sealed-to-permeable ratio changes over time, providing the evidence base for climate adaptation, water management and spatial planning decisions. Detection, classification and change monitoring are all part of a single, continuously updated dataset.
Methodology & Technology
We combine high-resolution satellite imagery, aerial photography, the BGT national topographic register and the national tree register (Boomregister) as input sources, processed through AI and machine learning models that automatically classify each surface pixel by type. This multi-source approach compensates for the limitations of any single input, ensuring completeness even where public registrations lag behind physical reality. The dataset is updated at minimum twice per year, with higher frequencies possible on request, and delivered with full transparency on source and quality level per classification.
Examples of what we detect
Sealed surface captures all fully impermeable coverings. Roads, pavements, building footprints, parking lots and other paved areas that prevent water from entering the soil. It is the core metric for calculating runoff volumes, dimensioning drainage infrastructure and assessing flood risk exposure.
Open paved surface identifies permeable or semi-permeable paving types such as gravel, clinker bricks with gaps and water-permeable tiles. This distinction is critical for water infiltration modelling. Not all paved surfaces behave the same way during heavy rainfall, and conflating them leads to systematic errors in drainage calculations.
Unsealed surface records areas of exposed soil, grass and other natural ground cover that allow water to infiltrate freely. It represents the ecological and hydrological buffering capacity of a location and is the reference point for assessing how much permeable surface has been lost over time.
This derived attribute expresses the proportion of sealed surface relative to the total area for any spatial unit. Parcel, neighbourhood, municipality or watershed. It is the primary indicator for regulatory thresholds, climate adaptation targets and ecological potential assessments such as BAF+.
Sealing change quantifies the net increase or decrease in sealed surface between two measurement moments. It provides the empirical basis for tracking policy targets on de-paving, monitoring the impact of new development on surface sealing, and verifying compliance with spatial planning commitments.
Output & integration
Impervious surface data is available via an interactive viewer for visual exploration at street, neighbourhood or municipal level, and via API for direct integration into GIS environments, drainage models and spatial planning tools. Exports are available per municipality, region or the full Netherlands. The dataset is updated at minimum twice per year, with change detection running continuously as new imagery becomes available. It combines directly with tree data for heat stress and BAF+ analysis, with water data for runoff and flood risk modelling, with building data for complete urban surface characterisation, and with parcel data for permit and development assessments.
Connected Intelligence
Challenge us.
We work with organisations that have specific, complex or non-standard data needs and we like it that way. Tell us what you’re looking for.
Explore our impervious surface data and it’s possibilities.
Steven Braakman
Expert Infra
