One of the most remarkable things I have read in a newspaper was in The EastAfrican two weeks ago.

It was tucked inside a story about Burundi president Pierre Nkurunziza complaining about Rwanda and its alleged bad neighbourly behaviour.

Nkurunziza, this newspaper reported, referenced a dispute over a hill in his New Year message. The hill, known as Sabanegwa in Rwanda and Sabanerwa in Burundi, is situated at the two countries’ common border.

As far as one can tell, this is the first major border shift caused by climate change, and not the last in Africa.

It is a fascinating story. The dispute, the report said, originated from the River Akanyaru — which has been used as a natural border between the two countries.

Over the years, the Akanyaru changed course, shifting in Burundi’s direction, and now the hill is on the Rwandan side.

The hill, which is about the size of the contentious Migingo Island in Lake Victoria, which Kenyans say Uganda (or more specifically President Yoweri Museveni) is trying to steal from them, looks like it wants to be just Sabanegwa.

If African borders were determined exclusively by map co-ordinates, this dispute wouldn’t be there. However, the colonialists parcelled out Africa among themselves, relying heavily on physical features.

To this day, especially because they are not marked, African borders are still settled by the “eyes of the communities” that live nearby, and these are based on physical features. So if the River Akanyaru moves, and yet it is what designates the border, the border too can be presumed to have moved – except if you go by the map.

An African Union official working on the even more contested border between Sudan and South Sudan, told this columnist once that it is the most trying job.

A meeting between the officials would agree on the co-ordinates of the borders on a map. Then they would go to draw the line in the ground, and chaos would break out.

Someone would say, over the dispute in the Abyei area, “From time immemorial, everyone has known the border between the Ngok Dinka and Misseriya is this valley”.

So a mapmaker would say something like, “But the map shows that the valley is deep in the Ngok Dinka area.” A (North) Sudan official would reply, “That may be so, but then it means the map is wrong.” You can’t win.

Burundi has been ravaged by climate change, and hit very hard by erosion. Many of its parts will continue to move in future.

And looking around Africa, many hills are going to move, and rivers and lakes will disappear or emerge.

Lake Chad touches four countries – Nigeria, Chad, Cameroon, and Niger. However, in the past 50 or so years, it has shrunk to 20 per cent of its previous size. Now there is land that was previously not demarcated. Who owns what bit?

What would have happened if the Akanyaru hadn’t changed course, and instead another river had emerged in floods on the opposite side, as in the Bugisu area in eastern Uganda?

Sabanegwa/Sabanerwa would now sit between Rwanda and Burundi. The ownership dispute would be even more intense. We are looking at the future. Clearly it has exciting stories waiting to be told.

Charles Onyango-Obbo is publisher of data visualiser Africapaedia and Rogue Chiefs. Twitter@cobbo3