Stripping nature: floods and biodiversity

I have a theory about the deep water the UK is in. A theory rooted in our abuse of nature, in our uprooting of stable, functioning ecosystems, throwing caution to the wind – literally.

What is a flood? Flooding is the unusual presence of water on land to a depth which affects normal activities. Flooding can arise from overflowing rivers, heavy rainfall over a short duration (flash floods), or an unusual inflow of seawater onto land (ocean flooding). Ocean flooding can be caused by storms such as hurricanes (storm surge), high tides (tidal flooding), seismic events (tsunami) or large landslides.

The UK is experiencing its fair share of flooding at the moment, blaming everything and everybody for the situation without getting to the real root cause of it. I think we are to blame: the farmers, the urbanites, the road and rail users, the policy makers – because we simply do not know what we are doing to the natural order of things.

Homes, businesses, farms and rail networks have been hard hit by the UK floods. Credit: Nicky Jenner.

Designed by nature

You see, nature has a way of dealing with high rainfall events and storms: in rainfall-prone areas, she covers the soils with thick, deeply-rooted plants, providing a network of vegetation that absorbs the water and hold the soils in place. Biodiverse ecosystems have a complexity and resilience that can take on more of the knocks that nature throws at us than eroded, heavily utilised or human-altered environments can.

A root matrix on a steep slope holding in soil and water. Credit: Pippa Howard/FFI.

Rich, dense vegetation in a landscape can dull the impact of a downpour, diluting, absorbing, channelling, holding and then slowly releasing water. Mangroves and salt marshes buffer coastal landscapes from storms, reducing the force of the onslaught by softening its power and slowing the erosive energy of wind and wave action. These systems are designed by nature to take on nature.

Mangroves stabilise the banks of the Amazon River, Brazil. Credit: Pippa Howard/FFI.

If you mess about with these systems, what happens? The services provided by ecosystems erode and things start to go wrong. If you remove vegetation from the land, soils are laid bare and are washed away. If you carve up a landscape, alter natural features, damage the soil structure, pave it, or build all over it, nature will battle to function.

Stripping the Amazon forest for mining causes water erosion, flooding, the buildup of particles in rivers and fish mortality, until revegetation occurs. Credit: Pippa Howard/FFI.

The result is that water has nothing to contain it and so it cascades randomly, violently, unchecked to downhill water courses that fill and overflow and burst. Or the water fills up field after field, creeping muddy entropy. It floods.

Flooded fields near Cambridge, England. Credit: Nicky Jenner.

Managing ecosystems to manage water

Forests, wetlands and other ecosystems influence the local, regional and global availability and quality of water. Forests can help regulate soil erosion and protect water supplies. Wetlands can be used to store water, clean water, reduce flood risks and allocate water to a wide range of users, from mountains to the sea. Soil biodiversity is critical for maintaining water and nutrient availability for plants, underpinning food security and reducing agricultural impacts on water.

If ecosystems are well-managed, we can use them as natural water infrastructure to achieve the same objectives as hard engineered infrastructure such as dams, pipelines, water treatment plants, irrigation systems, drainage networks and flood management embankments.

The bofidales, low-lying wetlands in the Altiplano plateau, Peru, are an example of important water-bearing landscapes. Credit: Pippa Howard/FFI.

The water crisis: too much, too little, too inequitable

We live in an increasingly water-insecure world. Currently 884 million people are living without safe drinking water and 2.5 billion people do not have adequate sanitation. By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world population could be under water stress conditions.

Water-related hazards, including droughts and floods, account for 90% of all natural hazards, and their frequency and intensity are generally rising. In 2010 alone, some 373 natural disasters killed more than 296,800 people, affected nearly 208 million others and cost nearly US $110 billion.

Under current trends, future demands on water to feed growing human populations, to supply intensive production of goods and to support growing economies will not be met.

Climate change will greatly affect water availability in many parts of the world, including Mongolia’s South Gobi Desert. Credit: Pippa Howard/FFI.

In developing countries, where water security is closely tied to what ecosystems provide, access to water is a political and health issue, a life force.

Women and young girls in many countries continue to carry the full burden of water inequality and for too many, water is literally a matter of life or death. Climate change exerts its impacts on people and ecosystems largely through water and increases the already significant risks. Although developing countries face the severest challenges, water is becoming increasingly insecure in rich nations too.

Biodiversity for life

Biodiversity underpins our water future. We need to protect natural systems because they provide the life force on which we depend.

We have the ability to rehabilitate soil biodiversity to deliver improved water availability to crops and increase food security, while simultaneously reducing water use and off-farm impacts. We can protect coastal communities from storms by strengthening coastal ecosystems as buffers and address desertification by restoring land cover and soils to keep water in the ground.

Revegetating to increase slope stability in Brazil. Credit: Pippa Howard/FFI.

So the UK floods are for real – but are we going to listen to what nature is telling us and will we do anything about it?

Fauna & Flora International (FFI) is helping companies integrate ecosystem scale water management to ensure the sustainability of water available to them and the communities they operate with and within. Read more about FFI’s work with the private sector.

Main image credit: Adrian Kingsley-Hughes/Flickr.