Land Surface Temperature Range Delta

Risksv015.00 credits/per_km2

Responsible:Niccolò Calandri

Land Surface Temperature Range Delta (LST Range Delta)

Overview

The LST Range Delta compares the mean surface temperature between two consecutive time periods. The annual LST mean represents the average surface temperature of the period. By computing the difference between the means of two distinct periods, we obtain a measure of how the surface thermal regime has changed over time.

Formula:

Delta = Mean_LST(period 2) - Mean_LST(period 1)
Mean_LST(period) = mean(LST, period)

Positive delta: seasonal thermal variability has increased — potentially indicating urbanization effects (more intense heat islands in summer), reduced vegetation cover (bare soil heating and cooling more rapidly), or local climate change with hotter summers and colder winters.
Negative delta: thermal variability has decreased, suggesting microclimate stabilization — possibly associated with reforestation, increased vegetation cover, or land management improvements mitigating thermal extremes.
Near-zero delta: the seasonal thermal regime has remained stable between the two periods.

LST is fundamental for environmental and climate monitoring. Changes in seasonal thermal range provide key insights into ecosystem health, urban mitigation policy effectiveness, and land use change impacts. This indicator is particularly useful for evaluating the impact of urban greening interventions, reforestation projects, and climate adaptation plans.

Calculation Methodology

Data acquisition: Landsat 8/9 images are collected for both reference periods, applying cloud, shadow, and snow masks.
LST calculation: surface temperature is computed for each image using the thermal band (Band 10) and emissivity correction algorithms (Split-Window or Mono-Window).
Mean calculation for period 1: the mean LST for the first period is computed pixel-wise across all valid scenes.
Mean calculation for period 2: the same mean calculation is repeated for the second period.
Delta calculation: pixel-wise subtraction: Delta = Mean(period 2) - Mean(period 1).
Validation: pixels lacking valid data in either period are masked as NoData.

Data Sources

Source Code	Name	Provider	Resolution	Availability
WRD_L8XXX_99	Landsat 8/9 Thermal	USGS/NASA	30m (100m native, resampled)	From 2013 (L8), 2021 (L9)

Technical Notes

Comparison requires valid data in both periods for each pixel. Areas with persistent cloud cover in one of the two years may produce gaps.
The native resolution of the Landsat thermal band is 100m, resampled to 30m for alignment with multispectral bands.
Differences in atmospheric conditions between the two years may introduce artifacts; results should be interpreted in the context of seasonal weather conditions.

References

Jiménez-Muñoz, J.C., et al. (2014). "Land surface temperature retrieval methods from Landsat-8 thermal infrared sensor data." IEEE Geoscience and Remote Sensing Letters, 11(10), 1840-1843.
Li, Z.L., et al. (2013). "Satellite-derived land surface temperature: Current status and perspectives." Remote Sensing of Environment, 131, 14-37.

Data Sources & References

Sources

WRD_L8XXX_99

Methodology

Il delta del range della LST viene calcolato confrontando i range annuali di temperatura superficiale tra due periodi consecutivi. Per ciascun periodo si calcola la media della LST. Il delta è ottenuto tramite sottrazione pixel per pixel: Delta = Media(periodo 2) - Media(periodo 1). I dati provengono da Landsat 8/9 (banda termica Band 10) con risoluzione 30m.