Land use and land cover
Background & relevance
Land use and land cover (LULC) are two overlapping concepts that describe the types of land features found on the Earth’s surface [Owers et al. 2021; Wulder et al. 2018]. The Earth’s surface is a mosaic of natural and non-natural land features, which land use and land cover classify into a pre-defined set of named classes [Grekousis et al. 2015].
Although theoretically similar, land use and land cover differ in the emphasis they place on different types of land features. Land cover emphasises physical features [FAO 2005], with classes typically including:
Land cover class | Notes |
|---|---|
Coastline | A line feature, so not explicitly quantified by all data sources |
Impervious surfaces | Includes paved surfaces and bare rock |
Bare rock | May be a subclass within “Impervious surfaces” |
Bare soil | May include subclasses for different soil types |
Snow & Ice | May include subclasses (e.g. sea ice, glacier, snowbed) |
Water bodies | May include subclasses (e.g. river, lake, pond) |
Terrestrial vegetation | Always includes subclasses (e.g. forest, grassland, wetland, cropland) |
Urban | May cover impervious (e.g. buildings) or green features (e.g. rooftop parks) |
Land use emphasises how humans use the Earth’s surface. Land use classes are less consistent among data sources than land cover classes [Fritz et al. 2017], but can include:
Land use class | Notes |
|---|---|
Agricultural | May include subclasses (e.g. cropland, rangeland) |
Urban | May include subclasses (e.g. residential, commercial, industrial) |
Protected area | May include subclasses (e.g. UNESCO, NNR, National Park) |
Recreational | - |
Land cover is a spatially explicit concept, meaning that a single point or pixel cannot be classified as more than one land cover class (e.g. water and forest). Land use also tends to be spatially explicit, although it is possible for there to be some overlap between land use classes (e.g. recreational and protected areas).
In combination, land use and land cover are not spatially explicit, in that it is usual for a point or pixel to have both a land use and land cover class. Some examples of this are protected forests (land use: protected area; land cover: forest), city parkland (land use: urban; land cover: rangeland), grazed peatlands (land use: agricultural; land cover: peatland), and developed coastline (land cover: coastline, land use: urban).
Areas containing multiple points or pixels are either represented as a grid of classes or aggregated to a relative fraction (%) of each class [Owers et al. 2021].
In practice, land use and land cover are usually combined into a single concept — here LULC — although some data sources only quantify one or other of them.
Importance
LULC is of foundational and direct importance to nature data teams, in that it contributes directly to business operations and regulatory compliance.
LULC is a basic identifier for what is present at a specific location at a given point in time. This makes LULC of direct value to strategic and operational workflows, including urban and regional planning, natural hazards monitoring, auditing natural assets (i.e. what is where), planning management interventions (e.g. new planting), and monitoring change over time (e.g. deforestation, infrastructure expansion).
LULC also supports other concepts by setting expectations about how a specific location should behave. Examples include using LULC classes to understand why species richness is low in certain areas (e.g. urban, cropland) and using LULC variation across a site to create a stratified sampling strategy for in situ measurements.
Finally, LULC is required for some regulatory compliance frameworks, such as the Taskforce for Nature Related Financial Disclosures (TNFD).
Dependencies & influences
Below are non-exhaustive lists of how LULC depends on and influences other concepts. Linked concepts can be existing or anticipated concepts, or may be concepts that are important but never actually operationalised.
LULC depends on
Concept | Details |
|---|---|
Policy and regulation | Local, national and international policies shape how humans are permitted to use the landscape and at what intensity; affects land cover through realised land use activities |
Human land use (conversion) | Human land use is a major determinant of land cover; logging converts land cover from forest to non-forest (vice versa for planting); urbanisation creates new urban land cover |
Topography | Slope, elevation, and aspect affect where different vegetation types grow and how humans use the landscape |
Erosion | Natural erosion caused by wind, water, or ice can shape land cover over long time periods; particularly obvious with soil erosion (e.g. exposure of bare rock) and retreating coastlines |
Natural disasters | Natural disasters, such as hurricanes, floods, wildfires, volcanic eruptions, and landslides, can cause changes in land cover — sometimes over very large areas |
Temperature | Temperature affects where different vegetation types grow and how humans use the landscape; climate warming can alter permanent ice extents (e.g. glacier retreat) and coastlines (i.e. sea level rise) |
Water availability | Water availability through groundwater, surface water, and precipitation affects where different vegetation types grow, how ice features and water bodies expand and contract, and how humans use the landscape |
Seasonal cycles | Seasonal cycles in temperature and precipitation expand and contract water bodies and seasonal ice; most relevant to temperate, polar, and mountainous regions |
Herbivory | Herbivores shape land cover mosaics by having preferences for certain vegetation types (e.g. tree saplings); herbivore population booms can convert land cover from one class to another |
Species migrations | Plant migrations into new areas can create a new LULC class (e.g. tree encroachment into tundra); animal migrations into new areas can alter existing land cover mosaics through herbivory |
LULC influences
LULC influences other scientific concepts directly and indirectly:
Direct [covered here]: LULC affects concepts that depend on the identity, abundance, or spatial patterns of specific LULC classes in a given area
Indirect [not covered here]: by describing land features with distinct characteristics, LULC can be used as an indirect indicator of the characteristics themselves (e.g. forest usually contains more plant biomass than cropland)
Concept | Details |
|---|---|
Topography | Human land use, including urban development and agriculture, alters topography |
Avalanche risk | Avalanche risk is higher where there is abundant snow and ice cover; vegetated land cover classes can act as physical avalanche barriers |
Landslide risk | Plant roots anchor soil to the ground and limit soil movement, making vegetated land cover classes less prone to landslides |
Fire risk | Vegetated land cover classes are fuel for fire, making wildfires more likely and intense where vegetated land cover classes are present; some land use practices alter the quantity and distribution of fuel in a landscape; particularly relevant to forests; spatial patterns of land cover in a landscape affect fire spread (e.g. firebreaks) |
Flood risk | Lateral water flow is faster across bare rock and urban areas, increasing flash flood risk in non-vegetated land cover classes; upland forests slow catchment discharge; land use practices that compact, remove, or alter soil (e.g. intense grazing) accelerate water discharge |
Soil erosion | Plant roots anchor soil to the ground and create a physical barrier to lateral water flow, making vegetated land cover classes more resistant to soil erosion; land use practices that compact, remove, or alter soil (e.g. intense grazing) accelerate rates of soil erosion |
Soil carbon stock | Land use designations (e.g. nature reserves) and conversion (e.g. from forest to cropland) affect the amount and spatial distribution of soil carbon |
Soil nutrient stock | Land use designations (e.g. nature reserves) and conversion (e.g. from forest to cropland) affect the amount and spatial distribution of soil nutrients |
Plant biomass | Land use designations (e.g. nature reserves) and conversion (e.g. from forest to cropland) affect the amount and spatial distribution of plant biomass |
Plant biodiversity | Land use designations (e.g. nature reserves) and conversion (e.g. from forest to cropland) affect the amount and spatial distribution of plant biodiversity; connected patches of natural land cover classes help to sustain plant diversity in managed landscapes |
Animal biodiversity | Land use designations (e.g. nature reserves) and conversion (e.g. from forest to cropland) affect the amount and spatial distribution of animal biodiversity; connected patches of natural land cover classes help to sustain animal diversity in managed landscapes |
Soil biodiversity | Land use designations (e.g. nature reserves) and conversion (e.g. from forest to cropland) affect the amount and spatial distribution of soil biodiversity |
Data requirements
The data that is used to quantify LULC. Variables come from three sources: (i) market demand; (ii) what science tells us is important; and (iii) what regulatory frameworks use.
Relevance: ability of variable to represent the concept of LULC
Scientific use: usage of variable in academic research
Regulatory use: usage of variable in regulatory nature frameworks
Name | Unit | Relevance | Scientific use | Regulatory use | Notes |
|---|---|---|---|---|---|
Consensus LULC class |
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| Consensus is the best LULC class assignment |
Presence/absence of LULC class |
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| Separate variables for each LULC class; pivoted version of consensus LULC class |
Probability of LULC class occurrence |
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| Separate variables for each LULC class; relative likelihood of a pixel being that class |
LULC class fractional cover |
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| Separate variables for each LULC class; fractional cover of that class within that pixel |
LULC change |
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| Change in a pixel/point LULC class over time; definitions of change and time vary |