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A global crisis – the human causes of flooding

A global crisis – the human causes of flooding

We all know by now that climate change is bad news, but did you know it’s been estimated we could lose 11 areas of England due to flooding as soon as 2050? To avoid this disaster we must educate ourselves on the human causes of flooding and what we can do help.

Throughout history we have encountered innumerable floods due to natural causes, from tsunamis, to costal storms and snow melt. However, recent years have seen a rapid increase of flooding with predictions this is set to worsen.

There are many human causes of flooding, both directly and indirectly. This begs the question- how much are we to blame for the current global crisis?

The direct human causes of flooding: the industrial revolution

The industrial revolution has had a significant impact on global warming and flooding. Our requirements for land has changed with the development of our agricultural, construction and mining industries.

What were once rolling hills now have been excavated, and built into urban developments to house families or assist with manufacturing, modern farming and mining. This has altered the floodplains and the way excess water from precipitation would flow across land, resulting in increased flooding in urban areas.

Industrial revolution and mining UK.

Human infrastructure

The dense population of land and urban infrastructure causes many complications.

There has been a perpetual requirement to develop property in close proximity, which has resulted in poorly planned developments with impervious materials. Together these factors cause natural water drainage pathways to be blocked.

Overwhelmed drains and sewage systems result in a significant lag time between peak rainfall, and when the water reaches a river or estuary where it can flow out to sea. We have higher chances of flooding as the water either looks for other routes to flow or stagnates.

Global warming has had an adverse effect on rain patterns, as warmer air results in more evaporation of water from land. A warmer atmosphere can also hold more water vapour which, in turn increases average rainfall and therefor flooding.

This cycle is known as surface water or pluvial flooding, and it has the ability to effect more people and properties than any other type of flood as it can happen anywhere. Another outcome of this process is that the entire cycle is sped up, resulting in more flash-flooding and surface water overflow.

There are some geographic factors such as the permeability of rocks and interception of vegetation that effect run-off rate, and in some cases will mobilise flooding causing a harsher aftermath.

London new buildings and developments.

Agriculture

Unsustainable farming practices is one of the many human causes of flooding, and farmers have their part to play in increased flood risk across the UK. Drainage is essential to ensure intense precipitation has routes to flow.

Bodies such as the RSPB suggest run-off rate is being directly impacted by the way we farm our land. Inappropriate cropping of land and farming of animals negatively effects the conditions of the soil.

Cattle and heavy machinery compact the earth, and intensive farming increases soil degradation, making it more vulnerable to wind and water erosion. As the soil is unable to store as much water, it increases water run-off and potential for flooding.

Soil erosion and flooding.

Levee and dam failure

To restrict and redirect the flow of water, humans create dams and levees. This form of water management requires regular maintenance as the man-made structures can degrade over time.

An unfortunate aspect to these structures is that they sometimes fail. This can result in mass flow of water which overwhelms drainage systems and results in flooding of our homes and properties.

Old English dam.

Deforestation

Another example of the human causes of flooding is the deforestation of land. Tree roots stabilise soil, helping it remain fertile with the required nutrients for plant growth.

Deforestation contributes to soil erosion as the top layer of soil is disturbed and left loose, increasing its vulnerability to the elements. Degraded land has less capacity to retain water, resulting in more flooding.

Trees also naturally intercept and absorb rainfall, so deforestation will both speed up the rain cycle and increase the amount of water run-off.

Another benefit of trees and vegetation is their ability to store carbon. Deforestation will reduce carbon stores, increasing levels trapped in our atmosphere which then heat the earths surface. This is an indirect contribution to the human causes of flooding, as it accelerates the cycle of climate change.

Deforestation in the UK.

The indirect human causes of flooding: global warming

Global warming has a cyclical nature, often referred to as the ‘earth system model‘. This accounts for the interaction of all activities which contribute to increased green house gases and subsequent rise in global temperatures.

Water cycle system - global warming

Earth system model of the water cycle – https://ugc.berkeley.edu/background-content/water-cycle/

This means there are indirect human causes of flooding whereby our daily activities have a knock-on effect that results in harsher weather conditions. The UK’s westernised lifestyle is a serious offender when it comes to increased production of green house gases and aggravation of this cycle.

Contributing factors to green house gas emissions include:

Green house gases drive climate change and disturb the natural processes which keep the earth harmonious. The ‘domino’ like effect shows how deeply engrained these processes are into society, and how increased flood risk is not a straight forward problem to solve.

Modern water use

The human causes of flooding can be linked to the manufacturing processes of our clothes and food right down to our individual daily water use. Water use currently accounts for 6% of the UK’s carbon emissions, thus fuelling the cycle.

The World Health Organisation states to fulfil our basic needs we need 20 litres of water per day. Domestically, we use far more than this- take a look at the average UK water usage per capita compared to that of someone in the developing world:

  • 142 litres per day
  • 10 litres per day (Equivalent to one toilet flush)

Further to this, industry and business accounts for an astronomical proportion of water usage. You may be under the impression living in the UK means we have an abundance of water available for use- this is far from the truth.

97% of the earth’s water is saline (salt water). Much of the remaining freshwater is retained in ice caps and as ground water leaving less than 1% of this available for consumption.

The dense population of land means the South of England receives less rain water per capita compared to countries such as South Sudan, which is often associated with droughts.

Furthermore, our daily activities mean much of our freshwater is polluted by sewage, road waste, single use plastic, industrial waste & chemicals and agricultural pesticides & fertilisers. This can even cause blockages and flooding itself.

We can treat water to improve its quality and availability so it is safe for consumption, however this all requires energy. One of the main by-products of this process is carbon-dioxide, which is released into the atmosphere and is one of the main driving factors of global warming.

CO2 emissions over the past 800,000 years.

Carbon Dioxide over the last 800,000 years – https://www.itv.com/news/2022-01-28/climate-explorers-what-is-co2-and-why-is-it-important-for-climate-change

The melting of ice caps and glaciers

One of the many consequences of global warming is the melting of ice caps and glaciers, which as a result leads to increased flooding.

Ice caps and glaciers are stores of ice on land, and when melted provide a source of water for domestic use, irrigation and hydropower. The rising temperature increase results in increased flow of water away from the glacier into our oceans.

Sea levels will continue to rise as the ice caps and glaciers shrink, until we reach the point of ‘peak meltwater’. This is when the water stores have diminished, and water availability reduces as they can no longer provide the constant flow we require.

Graph to show peak meltwater stages.

Peak Meltwater and glacier recession under a warming climate – https://www.antarcticglaciers.org/glaciers-and-climate/glacier-recession/glaciers-as-a-water-resource/

In an interview with the BBC, glaciologist Bethan Davies suggests we have potentially already surpassed this point- meaning the trending decline in water availability is set to worsen.

Moreover, as ice melts the reflection of the sun reduces, resulting in warmer oceans as they now absorb the suns heat. This is what is known as the albedo effect.

The influx of warm freshwater disrupts the oceans normal current patterns, resulting in colder temperature – with the changes to the Gulf Stream likely to impact the UK.

This is also when we will see an increase of volatile weather such as storms and hurricanes, destructing infrastructure and flooding our homes.

The sea levels rising will also likely contaminate the fresh water in our rivers with salt water, pushing us further under water stress and thus fuelling the cycle.

Destruction of eco-systems

Furthermore, the biodiversity of our marine life is significantly at threat due to the pollution, scarcity and temperature increase of our rivers and oceans. Biodiversity is crucial to support healthy eco-systems, which in turn provides us with vital resources to sustain our livelihoods, maintain global temperatures as well as reducing flood risk.

Coastlines across the globe are shielded from storms and surges by coral reefs and mangroves, including Cornwall and Scotland. These habitats, such as the famous Great Barrier Reef, have seen significant decline due to sea temperature increases, and scientists suggest they are at risk of being wiped out completely within the next 20 years.

As well as protecting our coastlines, the oceans coral ecosystems store vast quantities of earth’s carbon, which would otherwise be released into the air. This is the planets largest carbon sink, and the degradation of these wetlands is already releasing roughly 450 million tons (Mt) of carbon annually.

The human life-style relies on ocean micro-organisms which enrich soil where we can grow crops, and more than 3 billion people rely on fish and seafood as a significant source of animal protein.

The teetering fragility of marine life has the power to affect the lives of millions, biologically, economically and geopolitically. Jobs will be lost, seafood scarcity will lead to food insecurity & political tension, not to mention the communities which will be lost from flooding and decline of natural habitats.

Bleached and damaged coral reef.

The cyclical nature of the human causes of flooding, global warming and the destruction of our eco-systems has a knock on effect which is resulting in astronomical losses across the globe, from the loss of land to starvation.

Life on earth as we know it will not be the same.

The human causes of flooding: predictions for the future

A study by the University of Bristol suggests the cost of flooding to the UK could rise by more than 25% in some regions if we do not take action. If promises to reduce carbon emissions are kept, this could be reduced to just 5%.

The sophisticated data presented by the BBC shows a heat map of areas that are likely to be effected most.

BBC future flood risk map of UK.

Heatmap of areas which may be at risk of flooding if global warming persists past 1.8 °C – https://www.bbc.co.uk/news/science-environment-64866058

Scientists from the IPCC have sited its necessary to keep global temperature below 1.5 °C to reduce the intensity of suffering global warming is predicted to impose. Findings from the latest Synthesis report published March 2023 suggests it is still possible to achieve this, but we must act now.

The human causes of flooding: what we can do to help

There is no one individual to blame for the human causes of flooding, which means the solution also requires us to work together to combat climate change. The good news is, there are things we can all be doing as individuals and businesses to avoid this catastrophe.

  • Reduce our water usage
  • Reduce our carbon footprint
  • Re-build biodiversity
  • Conserve the natural world
  • Improve flood management

As businesses

Companies across the globe need to start taking responsibility for their part in global warming. We’ve recognised the importance of this issue, and committed to making it right by launching our own campaign to #RestoreThePlanet.

We have leaned on valuable resources from companies such as RSK and the Supply Chain Sustainability School, which provide education on a variety of business solutions such as:

  • Water use
  • Carbon footprints and achieving Net Zero
  • Industry pollution

Consider supporting green initiatives which look to innovate more sustainable technologies, rebuild and protect the earth’s natural eco-systems or overall just reduce the environmental impact humans have on the world.

It also pays to be prepared for potential flooding, even if you are not in a high risk area. Take a look at our guide on the risks of flood damage to commercial properties, and how to protect your business from flood damage.

For those in the agricultural industry, the Flood Hub provides vital resources for flood management both before and after it occurs.

As individuals

The first step is to cut down on your domestic water usage, there are many solutions that are free and easy to implement. We’d recommend reading our blog on water saving devices and habits to cut bills in 2023.

Education is key when learning about reducing your carbon footprint, and there are millions of online resources to help you along your path to sustainable living. Our friends at Composty have The Hack Shack, and alongside a wealth of eco products we’d whole-heartedly recommend as replacements to your standard cleaning supplies.

As all property is at risk of flooding, it is important to protect your home from water damage before it’s too late. If the damage has already occurred, follow our guide on What Do I Do When My House Floods?

Build back better is an initiative supported by many insurers which looks to improve property resilience measures following flood repairs, so the cost and impact of future floods are reduced. If your property has been effected, you may be eligible for help.


If you’re unfortunate enough to require flood restoration services – don’t worry, we can help. Rainbow Restoration are experts in water damage, and our teams of highly trained technicians will restore your property so you can get your life back to normal.

Published: 03 Apr 2023