The Country Similarity Index attempts to quantify how similar countries are to each other relative to other countries. The index is a statistically-based way to measure this. 20% of the index is based on geography. 12.5% of a country’s geography score (2.5% of the overall Country Similarity Index score) is allocated for the country’s land cover, including forests, croplands, grasslands, and barren land. The following are the factors that were included:
Generalized Land Cover
Generalized land cover is broken into four basic categories: Forested land, Vegetated land, Barren land, and Urban Area. Forested land is any land covered with trees. Vegetated land is any land with vegetation that is not covered with trees. Barren land is usually in deserts and mountainous areas, where there is no vegetation just sand or rock. Urban land cover is man-made built up zones like buildings, roads, and parking lots. Singapore and Bahrain are the only countries covered by the Index that have more than 20 percent urban land cover.
The Organisation for Economic Co-operation and Development sources of the data:
https://stats.oecd.org/Index.aspx?DataSetCode=Land_Cover
Land Cover
Land cover is then broken down into further subcategories. Vegetated land is split up into Shrub / grassland and Farmland. Unlike agriculture, shrub / grassland is not artificially planted by farmers and is naturally occurring. Botswana has one of the highest percentages of shrub land in the world. Ireland has one of the highest percentages of grassland in the world. Instead of intensive crop farming, much of Ireland’s land was traditionally used for pastoral agriculture by raising livestock on grassland.
The Organisation for Economic Co-operation and Development sources of the data:
https://stats.oecd.org/Index.aspx?DataSetCode=Land_Cover
Specific Landcover
Landcover is broken down into even more specific types. Shrub and grassland is separated into two distinct categories. In addition, the sparsely vegetated category is added. Australia and Iceland are two countries with a high percentage of land that is categorized as sparsely vegetated. The Outback in Australia is one example of a location that is sparsely vegetated but not completely barren. Iceland’s sparse vegetation is characterized by mosses and lichens. These form extensive carpets over bare ground and volcanic rock.
The Organisation for Economic Co-operation and Development sources of the data:
https://stats.oecd.org/Index.aspx?DataSetCode=Land_Cover
Calculation Method
The land cover of two different countries are compared using the following method as an example:
For Canada, the land cover distribution is as follows: 38% forests, 24% shrubland/grasslands, 5% urban areas, and 33% barren land. When converted to points rounded to the nearest tenth, Canada scores:
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Forests: 0.4 points
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Shrubland/Grasslands: 0.2 points
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Urban Areas: 0.1 points
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Barren Land: 0.3 points
This adds up to a total of 1.0 points.
For Mongolia, the land cover distribution is: 9% forests, 56% shrubland/grasslands, 1% urban, and 34% barren land. Converting and rounding to the nearest tenth gives:
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Forests: 0.1 points
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Shrubland/Grasslands: 0.6 points
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Urban Areas: 0.0 points (since 1% rounds down)
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Barren Land: 0.3 points
When comparing the two countries, we award each category the lower point value between them:
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Forests: min(0.4, 0.1) = 0.1
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Shrubland/Grasslands: min(0.2, 0.6) = 0.2
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Urban Areas: min(0.1, 0.0) = 0.0
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Barren Land: min(0.3, 0.3) = 0.3
Thus, the overall matching score is:
0.1 + 0.2 + 0.0 + 0.3 = 0.6 out of 1.0 points.