The Fractal Patterns of Landscapes Devastated by Drought

The beauty of nature works in mysterious ways. It can sometimes present itself in the harshest of landscapes, for example. Drought is a killer of animals, crops and people, yet there is an undeniable aesthetic appeal to the images of parched terrains that we are about to explore. As we will see, the effect of drought on the land, with the cracked and fractal patterns it leaves in its wake, can be almost hypnotic.

Drought occurs when there has been a period of time – months or years – with a clear reduction in precipitation, which leads to a dearth of either the surface or underground water supply in the affected region. The effect of these barren terrains on plant, animal and human life can be deadly.

When it comes to their effect on people, droughts don’t have to last decades to harm local agriculture. The entire annual production of farms be wiped out in a season, with crops decimated and animals either sent to slaughter – when the cost of keeping them fed and watered becomes too high – or, presumably for poorer farmers, simply left to die a slow death from lack of water.

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Although some parts of Australia experience 1,200 millimeters of rainfall per year, it is still Earth’s driest inhabited continent. The onset of drought varies from year to year and from place to place down under, but to the country’s government and its inhabitants, it represents a very real danger whenever and wherever it strikes.

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In truth, droughts have had a massive impact on human populations across the globe both in our own era and during times past. They’ve even shaped the way humans have settled our planet. For example, throughout history, climatic catastrophes such as drought have played a significant role in mass migrations – notably in the Horn of Africa, where a drought-related famine led to the deaths of 750,000 people between 1984 and 1985.

Droughts can also explain the mysteries of our past. The driest place in the world is the Atacama Desert in Chile. It contains areas so far removed from what we consider a normal landscape that NASA uses it to test its Mars dune buggies. And yet in days gone by, our ancestors occupied this now almost alien environment.

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Prehistoric human migration patterns in the Atacama Desert have, until recently, been something of a riddle. Researchers have now shown that while people lived in the region for thousands of years (from roughly 13,000 to 9,500 years ago), they then abandoned it – only to start returning a few thousand years later (which is to say about 4,500 years ago).

The cause of this ancient to-ing and fro-ing in northern Chile has left many scratching their heads, but a new interdisciplinary approach – the collaboration of two archeologists and a geoscientist – has shown that periods of extreme drought were the explanation for these puzzling movements.

In light of these mysteries, it’s perhaps fitting that the visible effects of drought on the soil – the cracks you see before you – are so mesmerizing to the eye. And yet there is an explanation. Mud cracks like these often occur when the earth contains an appreciable level of clay. According to geologist John H. Whitmore, mud cracks “form when clay-rich sediment dehydrates causing it to shrink and crack… They are more properly referred to as ‘desiccation cracks’ or ‘desiccation mud cracks’ but sometimes are called ‘sun cracks.’”

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Consequences of Drought

The consequences of drought are far-reaching and affect people differently, depending on their level of vulnerability. While subsistence farmers are more liable to migrate when drought strikes in order to find new sources of food, larger farms, which are relied on as a major food source by the local population, are more at risk to famines resulting from drought.

What little water remains in periods of drought is itself often of a lower quality: because pollutants in the water don’t get diluted to the same extent, contamination becomes more likely.

In this picture, the earth has been desiccated as far as the eye can see. Yet although we’re looking at a devastated landscape, one can’t help appreciating the jagged symmetry of the patterns nature has formed – which almost resemble the pieces of a giant jigsaw. It seems puzzles are never far from the picture!

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One thing is certain, though: as one of the most destructive natural phenomena, drought can wreak all kinds of havoc. Among its possible consequences are lowered crop growth, dust storms and dust bowls (which can lead to further erosion of the earth), wildlife habitat damage, malnutrition and dehydration in both animals and humans, wildfires, mass migration and wars over food and resources.

One of the most devastating wars of recent times was the Darfur Conflict in the Sudan, which has been exacerbated by the decades of drought that have plagued the country. And yet the grim reality of drought and the horrors of war seem distant when we look at this picture, in which the sun’s shimmering reflection on the parched earth makes it almost look like a seascape.

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The cracks in this particular desert close-up appear to run so deep that it almost looks as though you could fall in, and yet the illusion of a chasm seems somehow apt…

Notwithstanding the destructive impact of drought in Africa, such extended periods of dry weather are also of great concern in parts of India. Over the past three centuries, drought has been responsible for the deaths of tens of millions of people here – not least during the famine of 1876–1877, when a staggering five million people lost their lives.

Types of Drought

Interestingly, one of the major causes of drought is connected with anomalies in the temperature of the sea’s surface, which can lead to a heating up of the overlaying atmosphere. This, in turn, can affect large-scale atmospheric circulation patterns and, for many parts of the world, increase the likelihood of drought. A well-known example of one of these climate patterns is ‘El Niño’, which takes place about every five years in the equatorial Pacific Ocean. El Niño has been responsible for many of India’s severe droughts.

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Drought can be defined in three main ways. The first definition – and probably the one we are most familiar with – is meteorological drought. This is caused by an extended lack of rainfall or precipitation and is often the precursor to other types.

Agricultural drought affects the land’s ecology and its crops. While traditionally it is caused by meteorological drought, it can also be the result of poor agricultural decisions on the part of governments and farmers that lead to crops not getting enough water.

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The third main type of drought is hydrological, and is caused when reserves such as reservoirs, lakes and aquifers fall short of water. Because they involve sources of stored water being used and not refilled, hydrological droughts can take longer to be detected.

The patterns in the earth that drought creates are often overlooked – possibly because of the devastation it wreaks. Perhaps it is necessary to channel the detached vantage point of the artist or designer in order to fully appreciate the strange beauty these scenes present.

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Drought can affect every aspect of society. Lack of water leads to a lack of crops, and a lack of crops leads to a lack of food for animals, which in turn leads to a lack of sustenance for the humans that depend on both animals and crops for food. With a scarcity of drinking water added to the mix, the results are dehydration, starvation and ultimately death – sometimes on an unfathomable scale.

In this final image we see a landscape that simply seems to have given up. The mud has shrunk and cracked into fractals, which here look like giant flakes of peeling paint. Drought patterns like these are indeed one of nature’s wonders, but perhaps only if we forget the destruction they represent.

Sources: 1, 2, 3, 4, 5, 6, 7, 8, 9

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