Beyond the Numbers: How Projected vs Actual Area Could Shake Up the Census
Understanding the Actual Area of Burundi: Why It Matters
The population and housing census is in full swing. When we talk about the area of a country like Burundi, the figures we come across generally refer to a flat measurement of the land surface, obtained using geographic information systems (GIS). But what does this figure really mean, and does this measurement accurately reflect the actual area of the country, taking into account its relief?
Projected Surface vs. Real Surface
The area of 27,834 km² allocated to Burundi is a measure of the “Projected surface”. This measurement represents the horizontal projection of the earth’s surface on a flat map, completely ignoring variations in terrain. On the other hand, the “Real surface” of a country takes these topographical variations into account.
When the terrain is uneven, the actual area may be larger than the predicted area because the relief adds terrain. Imagine, for example, a flat piece of paper that you crease. The surface area of crumpled paper (the actual surface) is greater than when it is flat (the projected surface).
The Real Area of Burundi
Burundi is an East African country consisting mainly of plateaus and mountains. The Mirwa mountain range, located in the west, dominates a large part of the country. Because of this relief, the actual area of Burundi actually exceeds the projected area of 27,834 km².
For example, suppose a mountainous area in Burundi has an average slope of 10%. On a small projected area of 1 km² (1 km square on a flat map), the actual area could be slightly larger due to bias. Using simple geometric calculations, we can estimate that the actual area of this region would be approximately 1,005 km², an increase of 0.5% over the projected area.
Bhutan: A Textbook Case
Bhutan is one of the few countries that has tried to measure its real area taking into account the relief. In 2007, advanced geographical studies were carried out to obtain a more precise estimate of the country’s area. Bhutan, located in the Himalayas, has a very rugged terrain, with altitudes ranging from a few hundred meters to more than 7,000 meters above sea level.
By using digital terrain models (DTM) and geographic information systems (GIS), geographers were able to recalculate the area by integrating the country’s complex relief. The results showed that the actual area of Bhutan is significantly larger than that estimated by traditional plane projection methods.
Impact on the General Population Census
This difference between the projected area and the actual surface area is particularly important in the context of the general population and housing census currently underway in Burundi. When collecting population data, it is essential to consider the actual area, especially in mountainous areas where population density can be underestimated if only the projected area is used.
A precise understanding of the actual surface area makes it possible to better assess the distribution of the population and the needs for infrastructure, health services, education, and natural resources.
Why Knowing the Actual Area Matters
While Burundi’s projected area is officially 27,834 km², its actual area is likely to be larger, due to the country’s varied terrain. The case of Bhutan shows that it is possible, with modern technologies and rigorous methodology, to obtain a more precise estimate of the actual area of a country.
Knowing the actual area can also help us manage natural resources, such as water or forests, where accurate information about the actual area is essential for assessing how many resources are available. This can also help us in geopolitics and territory, because in some cases the actual area can influence territorial negotiations or international agreements.
