---
id: urban-heating
isHidden: true
name: Urban Heating
description: Collection of urban heat datasets featured in the "Implications for Heat Stress" Data Story
media:
  src: ::file ./media/urban-heat.jpg
  alt: Sunset over Tokyo
  author:
    name: Arto Marttinen
    url: https://unsplash.com/photos/6xh7H5tWj9c
taxonomy:
  - name: Subtopics
    values:
      - Air Quality
      - Heat
      - Surface Meteorology
  - name: Source
    values:
      - MODIS
infoDescription: |
  ::markdown
     Terra MODIS has been instrumental in capturing LST data. This platform, orbiting Earth, scans our planet in multiple spectral bands, allowing for a detailed analysis of LST values. The data periods 2000-2009 and 2010-2019 form this satellite have been particularly enlightening, revealing distinct shifts in Houston’s urban heat profile.
layers:
  - sourceParams:
      resampling: bilinear
      bidx: 1
      colormap_name: ylgn
      rescale:
        - -2000
        - 8500
    name: Houston NDVI
    legend:
      type: gradient
      min: "0"
      max: "1"
      stops:
        - '#ffffe5'
        - '#e5f5ac'
        - '#a2d88a'
        - '#4cb063' 
        - '#15793e'
        - '#004529'
    type: raster
    id: houston-ndvi
    description: "The Normalized Difference Vegetation Index (NDVI) is a calculation of vegetative cover and health"
    stacCol: houston-ndvi
    zoomExtent:
      - 2
      - 16
    compare:
      datasetId: urban-heating
      layerId: houston-ndvi
      mapLabel: |
        ::js ({ dateFns, datetime, compareDatetime }) => {
          if (dateFns && datetime && compareDatetime) return `${dateFns.format(datetime, 'yyyy')} VS ${dateFns.format(compareDatetime, 'yyyy')}`;
        }
    info:
      source: NASA
      spatialExtent: Houston
      temporalResolution: Annual 
      unit: N/A 

  - sourceParams:
      resampling: bilinear
      bidx: 1
      colormap_name: jet
      rescale:
        - 14300
        - 14830
    name: Houston LST Night
    legend:
      type: gradient
      min: "lower"
      max: "higher"
      stops:
        - '#000080' 
        - '#004cff' 
        - '#29ffce'
        - '#ceff29'
        - '#ff6800'
        - '#800000'
    type: raster
    id: houston-lst-night
    description: "The Land Surface Temperature (LST) data is MODIS-derived daily data, measured at 1 km spatial resolution." 
    stacCol: houston-lst-night
    zoomExtent:
      - 2
      - 16
    compare:
      datasetId: urban-heating
      layerId: houston-lst-night
      mapLabel: |
        ::js ({ dateFns, datetime, compareDatetime }) => {
          if (dateFns && datetime && compareDatetime) return `${dateFns.format(datetime, 'yyyy')} VS ${dateFns.format(compareDatetime, 'yyyy')}`;
        }
    info:
      source: NASA
      spatialExtent: Houston
      temporalResolution: Annual 
      unit: N/A 

  - sourceParams:
      resampling: bilinear
      bidx: 1
      colormap_name: jet
      rescale:
        - 14600
        - 15300
    name: Houston LST Day
    legend:
      type: gradient
      min: "lower"
      max: "higher"
      stops:
        - '#000080' 
        - '#004cff' 
        - '#29ffce'
        - '#ceff29'
        - '#ff6800'
        - '#800000'
    type: raster
    id: houston-lst-day
    description: "The Land Surface Temperature (LST) data is MODIS-derived daily data, measured at 1 km spatial resolution." 
    stacCol: houston-lst-day
    zoomExtent:
      - 2
      - 16
    compare:
      datasetId: urban-heating
      layerId: houston-lst-day
      mapLabel: |
        ::js ({ dateFns, datetime, compareDatetime }) => {
          if (dateFns && datetime && compareDatetime) return `${dateFns.format(datetime, 'yyyy')} VS ${dateFns.format(compareDatetime, 'yyyy')}`;
        }
    info:
      source: NASA
      spatialExtent: Houston
      temporalResolution: Annual 
      unit: N/A 


  - sourceParams:
      resampling: bilinear
      bidx: 1
      colormap_name: rdbu_r
      rescale:
      - -215
      - 215
    name: Houston LST Diff (Day)
    type: raster
    id: houston-lst-diff
    description: "Changes in decadally averaged land surface temperature (LST, daytime) in the Houston metro area. The higher the value, the larger the increase." 
    stacCol: houston-lst-diff
    zoomExtent:
      - 4
      - 16
    compare:
      datasetId: urban-heating
      layerId: houston-lst-diff
      mapLabel: |
        ::js ({ dateFns, datetime, compareDatetime }) => {
            if (dateFns && datetime && compareDatetime) return `${dateFns.format(datetime, 'yyyy')} VS ${dateFns.format(compareDatetime, 'yyyy')}`;
        }
    info:
      source: NASA
      spatialExtent: Houston
      temporalResolution: Annual 
      unit: N/A 

---
<Block>
  <Prose>
  ## Dataset Details
  ##### Land Surface Temperature 
  - **Temporal Extent:** 2000-2019
  - **Temporal Resolution:** Decadal
  - **Spatial Extent:** Houston, Texas
  - **Spatial Resolution:** 1 km
  - **Data Units:** Kelvin (K) 
  - **Data Type:** Research
  - **Data Latency:** N/A
  </Prose>
  <Figure>
<Map
      datasetId='urban-heating'
      layerId='houston-lst-day'
      dateTime='2000-01-01'
      compareDateTime='2010-01-01'
      compareLabel='2000-2009 Avg / 2010-2019 Avg'
      center={[-95.35, 29.8]}
      zoom={8.75}      
    />
    <Caption>
      Comparison of decadally-averaged daytime land surface temperature (LST) between 2000-2009 and 2010-2019 showing urban heating in the Houston Metropolitan Area.
    </Caption>
</Figure>
</Block>

<Block>
<Figure>
<Map
      datasetId='urban-heating'
      layerId='houston-ndvi'
      dateTime='2000-01-01'
      compareDateTime='2010-01-01'
      compareLabel='2000-2009 Avg / 2010-2019 Avg'
      center={[-95.35, 29.8]}
      zoom={8.75}      
    />
    <Caption>
      Comparison of decadally-averaged Normalized Difference Vegetation Index (NDVI) between 2000-2009 and 2010-2019 showing green space reduction in the Houston Metropolitan Area.
    </Caption>
</Figure>
  <Prose>
  ##### Normalized Difference Vegetation Index 
  - **Temporal Extent:** 2000-2019
  - **Temporal Resolution:** Decadal
  - **Spatial Extent:** Houston, Texas
  - **Spatial Resolution:** 250 m
  - **Data Units:** Unitless
  - **Data Type:** Research
  - **Data Latency:** N/A
  </Prose>
</Block>

<Block>
  <Prose> 
  ## Overview
    
  Urban heat islands (UHIs) are no longer merely academic concepts; they’re palpable urban challenges. In rapdily urbanizing cities such as Houston, understanding the dynamics of land surface temperature (LST) is not just about decoding satellite data, but comprehending its implications for urban planning, health, and socioeconomic dynamics. Leveraging data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS)) platform, we delve into Houston’s changing landscape over two decades by examining multi-decadal changes both LST and the Normalized Difference Vegetation Index (NDVI), offering a technical perspective on this urban phenomenon. LST is the temperature of the earth’s surface derived from the Terra satellite that houses the MODIS instrumentation, encompassing both natural terrains and man-made infrastructures. Unlike ambient air temperature, which gauges the immediate atmospheric conditions we feel, LST provides a granular temperature profile of surfaces from park greens to asphalt roads. Exmaining this in conjunction with NDVI gives an idea of the changing access to green space in sprawling urban spaces such as Houston.
  </Prose>
</Block>

<Block>
  <Prose>
  ## Data Acquisition

  Terra has been instrumental in capturing this data. This platform, orbiting Earth, scans our planet in multiple spectral bands, allowing for a detailed analysis of LST and NDVI. The decadal periods of 2000-20009 and 2010-2019 were examined specifically to study the growth of Houston's UHI.

  Comparative analysis of LST data from the two decades indicate a tangible uptick in surface temperatures, especially in Houston’s southwestern regions. Urban expansion is likely culprit, with infrastructural growth leading to increased heat absorption and radiation. This phenomenon, known as the urban heat island effect, can intensify local temperatures, leading to a cascade of socio-environmental effects.

  Users can access MODIS data for anywhere across the globe [here](https://modis.gsfc.nasa.gov/data/), or click 'Explore Data' at the top of this page for a quick examination of the specific data used in this study.
  </Prose>
</Block>

<Block>
  <Prose>
  ## Importance of Heat Stress Datasets
  
  MODIS LST and NDVI data serves as a crucial pointer for urban planners, environmentalists, and policymakers. By understanding the nexus of urban heat, infrastructure, and socioeconomics, we can shape urban features that are not only sustainable but also equitable. As Houston continues to rapidly urbanize, it has the potential to redefine urban resilience in the face of escalating heat challenges.
  </Prose>
</Block>

<Block>
  <Prose>
  ## Disclaimer
  All data provided in VEDA has been transformed from the original format (TIFF) into Cloud Optimized GeoTIFFs ([COG](https://www.cogeo.org)). Careful quality checks are used to ensure data transformation has been performed correctly.  
  </Prose>
</Block>

<Block>
  <Prose>
  ## Key Publications

  Didan, K., Munoz, A.B., Solano, R., and Huete, A. (2015). MODIS vegetatin index user's guide (MOD13 series). University of Arizona Veg. Index Phenol. Lab

  Wan, Z. (2014). New refinements and validation of the collection-6 MODIS land-surface temperature/emissivity product. *Remote Sensing of the Environment, 140*, 36-45. https://doi.org/10.1016/j.rse.2013.08.027

  **The citation below is a peer-reviewed study that stemmed from this research, written by the authors of the associated data story:**

  Blackford, A., Cowan, T., Nair, U., Phillips, C., Kaulfus, A., and Freitag, B. (2024). Synergy of urban heat, pollution, and social vulnerability in one of America's most rapidly growing cities: Houston, we have a problem. *GeoHealth, 8*, e2024GH001079. https://doi.org/10.1029/2024GH001079
  </Prose>
</Block>

<Block>
  <Prose>
  ## Data Stories Using This Dataset
  **[Implications for Heat Stress](https://www.earthdata.nasa.gov/dashboard/stories/urban-heating)**
  </Prose>
</Block>

<Block>
  <Prose>
  ## License
  [Creative Commons Attribution 1.0 International](https://creativecommons.org/publicdomain/zero/1.0/legalcode) (CC BY 1.0)

  </Prose>
</Block>