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  • Product Sheet: Vegetation Stress

Vegetation Stress and degradation

 

Bush encroachment in Nigeria (Source: Diversity II)

PRODUCT DESCRIPTION

Category

Component products

Land Cover

 

  • NDVI
  • fAPAR
  • LAI
  • Rainfall estimates

Uses

  • Environmental monitoring – Baseline historic mapping of environment and ecosystems
  • Environmental monitoring – Continuous monitoring of changes throughout the lifecycle

Geo-information requirements

  • Detailed land cover information
  • Critical habitat identification

Description

This product provides information on vegetation stress and degradation (resulting in reduced vegetation ‘productivity’) on a long time scale and range of spatial scales based on optical satellite data. Vegetation trend observations can help pin-pointing areas of change, act as a land degradation assessment tool and indicator of where to focus further investigations, potentially as the basis for possible interventions.

There are different methodologies to derive vegetation stress. Most methodologies use time series of vegetation indices (e.g. fAPAR – Fraction of Absorbed Photosynthetically Active Radiation, NDVI – Normalized Differenced Vegetation Index or LAI – Leaf Area Index).

To separate short term (e.g. drought driven) vegetation stress from the long term vegetation stress that causes vegetation degradation, a time series of imagery is needed. In addition, meteorological data/indicators, such as rainfall estimates can be used to calibrate results to distinguish between long term changes and weather induced (e.g. drought) short term changes.

Known restrictions / limitations

  • In tropical areas frequent cloud cover can be an issue for the production of the optical maps. In general, the assessment of vegetation stress requires the availability of historical EO data to contrast the present condition and for long term monitoring.
  • To monitor vegetation stress a time series of radiometrically-normalised products is required.
  • Often, a compromise is made between the time frequency of image acquisition and resolution.  For example, currently available frequent time series technology tends to generate images of relatively coarse spatial resolution.

Lifecycle stage and demand

Pre-licensing

Exploration

Development

Production

Decommissioning

 

 

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Development:

  • Baseline information on vegetation health

Production:

  • Assessment of land degradation processes to pinpoint areas of change

Decommissioning:

  • Information on vegetation stress as indicator of ecosystem recovery

Geographic coverage and demand

Demand in semi-arid and arid areas.

CHALLENGES ADDRESSED

OTM:022 Detecting hydrocarbon leaks

OTM:062 Monitoring re-vegetation

 

HC:4205 Remediation monitoring related to agriculture impacts

HC:5402 Detection of pipeline leaks

HC:4201 Remediation and reclamation monitoring

PRODUCT SPECIFICATIONS

Input data sources

Optical: HR1, HR2, MR1, MR2

Radar: VHR2

Supporting data:

  • EO-based Evapotranspiration data
  • Satellite Rainfall Estimate (RFE)
  • Aerial and UAV imagery

Spatial resolution and coverage

Spatial resolution: 4 m – 300 m pixel size

Minimum Mapping Unit (MMU)

n/a (data product)

Accuracy / constraints

n/a (data product)

Accuracy assessment approach & quality control measures

Comparing with known stressed and unstressed areas measured in the field using, for example, chlorophyll fluorometers.

Frequency / timeliness

Observation frequency: The frequency is constrained by satellite revisit and acquisition timeframes as well as processing requirements. Whilst the minimum frequency is technically driven by the revisit cycle of the satellite, the maximum frequency is defined be the customer. Depending on the requirements of the customer the most suitable satellite sensor has to be selected considering spatial / spectral resolution as well as revisit frequency. Typically, vegetation stress is mapped on a 3 to 5 year basis, but the frequency can be lower or higher depending on demand).

Timeliness of deliverable: Methods can be adapted to meet the demand on timeliness (e.g. near real time)

Availability

Freely available or commercially acquired depending on the sensor selected.

Delivery / output format

Data type:

  • Vector formats
  • Raster formats (depending on customer needs)

File format:

  • Geotiff or shapefile (standard - any other OGC standard file formats)

 


 Download product sheet.

 

Lead Author:GeoVille
Peer Reviewer:Hatfield Consultants

Author(s):

Maria Lemper, Jan Militzer

Document Title:

Vegetation Stress and degradation

# of Pages:

5

Circulation:

Internal – Project consortium and science partners

 

External – ESA

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