About EvaGrid

Overview

EvaGrid is an interactive geospatial analysis tool for assessing climate impact across grid cells. It combines exposure and sensitivity factors to calculate and visualize environmental impact using a weighted multi-criteria approach.

How It Works

The tool calculates Impact for each grid cell using the formula:

Impact = Exposure × Sensitivity

Both Exposure and Sensitivity are calculated as weighted sums of normalized utility values (0-1 range), where the weights sum to 1.0 (100%).

Exposure Factors

Exposure represents the environmental conditions and stressors affecting each grid cell:

  • Land Surface Temperature (LST): Measures thermal stress from surface heating
  • Chill Index: Quantifies cold stress and winter conditions
  • Solar Radiation: Captures solar exposure and heat gain
  • Inhabitants: Represents population density and human exposure

Default weights: LST 25%, Chill Index 28%, Solar 22%, Inhabitants 25%

Sensitivity Factors

Sensitivity represents the vulnerability and adaptive capacity of each grid cell:

  • Proximity to Waterbody: Distance to water sources affecting microclimate regulation
  • Porosity: Urban fabric permeability and air circulation capacity
  • Built Volume to Heat: Thermal mass and heat retention in buildings
  • Zonal Mean Altitude: Elevation effects on temperature and climate

Default weights: Proximity to Waterbody 30%, Porosity 20%, Built Volume 30%, Altitude 20%

Interactive Controls

Click the grid control button on the map to open the weight adjustment drawer. The drawer features:

  • Two-column layout: Separate controls for Exposure and Sensitivity
  • Dynamic sliders: Adjust weights in 1% increments (0.01 steps)
  • Auto-normalization: Moving one slider automatically redistributes others to maintain 100% total
  • Real-time visualization: Map colors update instantly as you adjust weights
  • Reset button: Restore all weights to their default values

Color Scale

The map uses a color gradient calibrated to the actual impact value range (0.19 - 0.55):

Low Impact (0.19) High Impact (0.55)
  • Light yellow: Very low impact
  • Green shades: Low to moderate impact
  • Teal to blue: Moderate to high impact
  • Dark blue: Very high impact

Use Cases

EvaGrid supports various applications in climate adaptation and urban planning:

  • Identifying climate hotspots requiring intervention
  • Comparing different weighting scenarios for policy decisions
  • Prioritizing areas for climate adaptation measures
  • Understanding the interplay between exposure and sensitivity
  • Communicating climate risk to stakeholders