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Land use is an umbrella term to describe what happens on a parcel of land. It concerns the benefits derived from using the land, and also the land management actions that humans carry out there. The following categories are used for land use: forest land, cropland (agricultural land), grassland, Wetland, Human settlement and other lands. The way humans use land, and how land use is changing, has many impacts on the environment. Effects of land use choices and changes by humans include, for example, urban sprawl, soil erosion, soil degradation, land degradation and desertification. UN Land Degradation and Land Use/Cover Data Sources ret. 26 June 2007 Land use and land management practices have a major impact on natural resources including water, soil, , and .
Land use change is "the change from one land-use category to another". Land-use change, together with use of , are the major anthropogenic sources of carbon dioxide, a dominant greenhouse gas. Human activity is the most significant cause of land cover change, and humans are also directly impacted by the environmental consequences of these changes. For example, deforestation (the systematic and permanent conversion of previously forested land for other uses) has historically been a primary facilitator of land use and land cover change.
The study of land change relies on the synthesis of a wide range of data and a diverse range of data collection methods. These include land cover monitoring and assessments, modeling risk and vulnerability, and land change modeling.
Another definition is that of the United Nations' Food and Agriculture Organization: "Land use concerns the products and/or benefits obtained from use of the land as well as the land management actions (activities) carried out by humans to produce those products and benefits." FAO Land and Water Division retrieved 14 September 2010
As of the early 1990s, about 13% of the Earth was considered arable land, with 26% in pasture, 32% forests and woodland, and 1.5% urban areas.
As of 2015, the total arable land is 10.7% of the land surface, with 1.3% being permanent cropland.
For example, the US Department of Agriculture has identified six major types of land use in the United States. Acreage statistics for each type of land use in the contiguous 48 states in 2017 were as follows:
| +US land use (2017) !Use !acreage (M) !km2 (M) !% of total | |||
| Pasture/Rangeland | 654 | 2.647 | 35 |
| Forest | 538.6 | 2.18 | 28 |
| Cropland | 391.5 | 1.584 | 21 |
| Special use | 168.8 | 0.683 | 9 |
| Miscellaneous | 68.9 | 0.279 | 4 |
| Urban area | 69.4 | 0.281 | 4 |
| Total | 1,891 | 7.653 | 100 |
Human activity is the most significant cause of land cover change, and humans are also directly impacted by the environmental consequences of these changes. Collective land use and land cover changes have fundamentally altered the functioning of key Earth systems. For instance, human changes to land use and land cover have a profound impact on climate at a local and regional level, which in turn contributes to climate change.
Land use by humans has a long history, first emerging more than 10,000 years ago. Human changes to land surfaces have been documented for centuries as having significant impacts on both earth systems and human well-being. Deforestation is an example of large-scale land use change. The deforestation of since 1750 has had a major effect on land cover. The reshaping of landscapes to serve human needs, such as the deforestation for farmland, can have long-term effects on earth systems and exacerbate the causes of climate change.
Although the burning of fossil fuels is the primary driver of present-day climate change, prior to the Industrial Revolution, deforestation and irrigation were the largest sources of human-driven greenhouse gas emissions. Even today, 35% of anthropogenic carbon dioxide contributions can be attributed to land use or land cover changes. Currently, almost 50% of Earth’s non-ice land surface has been transformed by human activities, with approximately 40% of that land used for agriculture, surpassing natural systems as the principal source of nitrogen emissions.
Increasing land conversion by humans in future is not inevitable: In a discussion on response options to climate change mitigation and adaptation an IPCC special report stated that "a number of response options such as increased food productivity, dietary choices and food losses, and waste reduction, can reduce demand for land conversion, thereby potentially freeing land and creating opportunities for enhanced implementation of other response options".IPCC, 2019: Summary for Policymakers. In: Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems P.R.. https://doi.org/10.1017/9781009157988.001
Studying risk and vulnerability entails the development of quantitative, qualitative, and geospatial models, methods, and support tools. The purpose of these tools is to communicate the vulnerability of both human communities and natural ecosystems to hazard events or long-term land change. Modeling risk and vulnerability requires analyses of community sensitivity to hazards, an understanding of geographic distributions of people and infrastructure, and accurate calculation of the probability of specific disturbances occurring.
There is rarely one direct or underlying cause for deforestation. Rather, deforestation is the result of intertwining systemic forces working simultaneously or sequentially to change land cover. Deforestation occurs for many interconnected reasons. For instance, mass deforestation is often viewed as the product of industrial agriculture, yet a considerable portion old-growth forest deforestation is the result of small-scale migrant farming. As forest cover is removed, forest resources become exhausted and increasing populations lead to scarcity, which prompts people to move again to previously undisturbed forest, restarting the process of deforestation. There are several reasons behind this continued migration: poverty-driven lack of available farmland and high costs may lead to an increase in farming intensity on existing farmland. This leads to the overexploitation of farmland, and down the line results in desertification, another land cover change, which renders soil unusable and unprofitable, requiring farmers to seek out untouched and unpopulated old-growth forests.
In addition to rural migration and subsistence farming, economic development can also play a substantial role in deforestation. For example, road and railway expansions designed to increase quality of life have resulted in significant deforestation in the Amazon and Central America. Moreover, the underlying drivers of economic development are often linked to global economic engagement, ranging from increased Export to a External debt.
Urbanization is important to land use and land cover change for a variety of reasons. In particular, urbanization affects land change elsewhere through the shifting of urban-rural linkages, or the ecological footprint of the transfer of goods and services between urban and rural areas. Increases in urbanization lead to increases in consumption, which puts increased pressure on surrounding rural lands. The outward spread of urban areas can also take over adjacent land formerly used for crop cultivation.
Urbanization additionally affects land cover through the urban heat island effect. Heat islands occur when, due to high concentrations of structures, such as buildings and roads, that absorb and re-emit solar radiation, and low concentrations of vegetative cover, urban areas experience higher temperatures than surrounding areas. The high temperatures associated with heat islands can compromise human health, particularly in low-income areas.
Additionally, scientists have been able to use technology such as NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) to track changes to the Aral Sea and its surrounding climate over time. This use of modeling and satellite imagery to track human-caused land cover change is characteristic of the scope of land change science.
The urban growth boundary is one form of land-use regulation. For example, Portland, Oregon is required to have an urban growth boundary which contains at least of vacant land. Additionally, Oregon restricts the development of farmland. The regulations are controversial, but an economic analysis concluded that farmland appreciated similarly to the other land.Jaeker WG, Plantinga AJ (2007). How have Land-use regulations Affected Property Values in Oregon? OSU Extension.
Today, federal, state, and local governments regulate growth and land development through statutory law. The majority of controls on land, however, stem from the actions of private developers and individuals. Judicial decisions and enforcement of private land-use arrangements can reinforce public regulation, and achieve forms and levels of control that regulatory zoning cannot. There is growing concern that land use regulation is a direct cause of housing segregation in the United States today.
Two major federal laws passed in the 1960s limit the use of land significantly. These are the National Historic Preservation Act of 1966 (today embodied in 16 U.S.C. 461 et seq.) and the National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.).
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