Editing Linear Trend Slope in Burned Area

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{| class="wikitable" style="float:right; clear:right; margin:0 0 1em 1em; width:320px;"
|+ SIGNAL Earth Structured Data
|-
! Object type
| Damage Signal
|-
! SIGNAL Earth ID
| DS-00658
|-
! Observable type
| Burned area
|-
! Unit
| ha (ha)
|-
! Temporal structure
| Annual
|-
! Monitoring backbone
| MODIS / ESA
|}
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The {{SignalTerm|type=DS|id=DS-00658|label=Linear Trend Slope in Burned Area}} quantifies the rate of change over time in the extent of land affected by fire. This measurement captures the annual increase or decrease in burned area, expressed in hectares per year, providing insight into long-term fire activity trends globally. Understanding these trends is critical for assessing ecosystem dynamics, carbon emissions, and land management impacts.

Wildfires and other fire events play a significant role in shaping terrestrial ecosystems, influencing vegetation patterns, soil properties, and atmospheric composition. The linear trend slope in burned area serves as an indicator of changing fire regimes, which may be driven by climatic variations, land use changes, and anthropogenic factors.

Within the context of global environmental monitoring, this signal helps to characterize pressures and stressors on the land domain. It supports scientific assessments related to fire frequency, intensity, and spatial distribution, contributing to broader analyses of environmental change and its drivers.

== Geographic / System Context ==
This signal encompasses the global terrestrial surface, capturing burned area trends across diverse ecosystems including forests, grasslands, savannas, and shrublands. Fire activity varies regionally due to differences in climate, vegetation type, human land use, and fire management practices. Regions such as boreal forests in the Northern Hemisphere, tropical savannas, and Mediterranean landscapes exhibit distinct fire regimes that influence the spatial and temporal patterns of burned area.

The global scope allows for comparative analysis across continents and biomes, facilitating the identification of hotspots of increasing or decreasing fire activity. Such geographic context is essential for interpreting the ecological and climatic implications of observed trends in burned area.

== Monitoring and Measurement ==
Monitoring of burned area and its temporal trends relies primarily on satellite remote sensing platforms. The Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard [https://en.wikipedia.org/wiki/NASA NASA]'s Terra and Aqua satellites provide the foundational burned area products, such as the MCD64A1 dataset, which detects fire scars at a spatial resolution suitable for global coverage.

Additionally, the European Space Agency's (ESA) Fire Climate Change Initiative (FireCCI) produces burned area products that complement MODIS data, offering refined spatial and temporal information. These datasets are generated using algorithms that identify changes in surface reflectance indicative of recent burns.

The Global Fire Emissions Database (GFED) integrates satellite-derived burned area with emissions modeling to support fire-related carbon flux assessments. The annual burned area data derived from these sources are analyzed to compute linear trend slopes, representing the rate of change in burned area extent over multiple years.

Within the SIGNAL system, this phenomenon is treated as a defined environmental signal whose boundaries and measurement conventions are described below.

== Signal Definition ==
The linear trend slope in burned area is defined as the annual rate of change in the total area affected by fire, measured in hectares per year (ha/year). It is derived from the time series of annual burned area data obtained from satellite observations. This signal quantifies whether the extent of burned land is increasing, decreasing, or stable over a specified temporal window, typically spanning multiple years to decades.

== Boundary Conditions ==
Boundary inclusions encompass all terrestrial land surfaces globally where burned area can be detected reliably by satellite sensors, including natural vegetation types such as forests, grasslands, shrublands, and agricultural lands affected by fire. Both natural wildfires and anthropogenic fires are included.

Boundary exclusions involve areas where burned area detection is limited or unreliable due to persistent cloud cover, snow, ice, or water bodies. Urban areas with minimal vegetation and permanent ice caps are excluded as burned area is not applicable. Additionally, very small or low-intensity burns below the detection threshold of satellite sensors may not be captured.

== Aggregation Semantics ==
Geographic aggregation involves summarizing burned area data at various spatial scales, from local to regional to global extents, enabling the computation of trend slopes within defined geographic units. Temporal aggregation is conducted on an annual basis, with the linear trend slope calculated over multi-year periods to capture long-term changes rather than short-term variability.

Cross-signal aggregation may integrate burned area trends with other environmental signals such as vegetation health, carbon emissions, or climate variables to assess interactions and compound effects. Aggregation notes emphasize the importance of consistent temporal and spatial resolution in datasets to ensure comparability and robustness of trend estimates.

== Observational Status ==
Current observational capabilities provide global burned area data with annual temporal resolution, enabling the calculation of linear trend slopes over recent decades. The MODIS and ESA FireCCI products form the backbone of these measurements, supported by databases such as GFED. Ongoing improvements in satellite sensor technology and algorithm development continue to enhance the accuracy and spatial detail of burned area detection.

Future SIGNAL releases may incorporate higher-resolution datasets, expanded temporal coverage, and integration with additional environmental variables to refine trend analyses and improve understanding of fire dynamics under changing climate and land use conditions.

== Related Signals ==
* None specified

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== Key Associated People ==
* '''James T. Randerson''' — Contributor (UC Irvine) [Domain expert]
* '''Luigi Giglio''' — Contributor (University of Maryland) [Domain expert]
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== Sources ==
* [https://www.globalfiredata.org/ GFED (Global Fire Emissions Database)]
* [https://doi.org/10.1016/j.rse.2019.111589 MODIS Burned Area product (MCD64A1) documentation]
* [https://climate.esa.int/en/projects/fire/ ESA FireCCI burned area products]
* [https://www.ipcc.ch/report/ar6/ IPCC AR6 fire / land chapters (wildfire trends)]
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