A 4 Earth Intelligence Case Study for Norwich City Council (UK)

This case study details the findings and deliverables of an environmental mapping and trend analysis project commissioned by Norwich City Council (NCC) and executed by 4 Earth Intelligence (4EI). The primary objective of this project was to provide comprehensive, evidence-based environmental data concerning heat hazards and vegetation cover within the NCC area. This high-resolution data is crucial for informing future urban planning, climate resilience strategies, and environmental management initiatives.

Project Objectives & Scope

To establish a precise baseline of current green infrastructure and thermal risk, 4EI structured the project around three main analytical components:

• Heat Hazard Mapping (2020-2025): 4EI utilised thermal infrared band data from Landsat 8 and 9, ECOSTRESS, and MODIS satellite missions to derive Land Surface Temperature (LST) as a proxy for heat hazard.
  • Peak summer data from 2020 to 2025 was processed, filtered for cloud cover, and standardized to create a composite Heat Hazard Index (HHI).
  • The resulting maps illustrate that the highest heat hazards are concentrated within the dense urban core and areas with large expanses of impervious surfaces.
  • Quantitatively, 51% of the study area (20.164 km2) was classified as experiencing ‘High’ heat hazard, and 5% (2.031 km2) as ‘Very High’. Conversely, parks and peri-urban green belts exhibited substantially lower risk.

• Tree Canopy Mapping (2025): To quantify contemporary green infrastructure, 4EI utilised high-resolution Vantor (Maxar) WorldView-3 (WV-3) satellite imagery acquired in 2025.
  • Instead of traditional per-pixel classification, an Object-Based Image Analysis (OBIA) approach was used alongside a Random Forest machine learning model to segment and classify land cover into Tree, Grass, Urban, and Water classes.
  • The analysis successfully delineated the canopy, revealing a total tree canopy cover of 10.95 km2, which represents 28% of the total Norwich City Council area.

• Environmental Trend Analysis (2015-2025): This component aimed to quantify the decadal change in vegetation cover and heat hazard.
  • 4EI integrated historical Landsat 8/9 heat hazard data with MODIS Vegetation Continuous Fields (VCF) products.
  • Data was spatially aggregated to 2021 Lower-layer Super Output Area (LSOA) boundaries to provide stable, neighbourhood-wide signals relevant for local planning.
  • Using the Sen’s Slope estimator and Mann-Kendall tests for statistical significance, the 10-year trend analysis revealed that both heat hazard and tree canopy cover have remained predominantly stable across the majority of the city, with only a few localized LSOAs exhibiting statistically significant increases or decreases.

Conclusion

By integrating multi-sensor satellite data and advanced machine learning classification, 4EI successfully delivered a granular assessment of Norwich’s urban environment. While the decadal trends show broad stability, the precise 2025 baseline maps highlight stark spatial differences in heat exposure and canopy distribution. These insights directly empower Norwich City Council to target its climate adaptation efforts, ensuring that future urban forestry and resilience strategies are deployed where they are needed most.

Contact Information and Links

To find out more please get in touch or reach out to us at info@4earthintelligence.com.