Now a major issue across the globe, climate change has led to an increase of extreme weather events in the UK, including higher average temperatures, longer warm spells, as well as unpredictable bouts of heavy rainfall. While for many, periods of warmer weather may sound like good news, climate change is a grave concern for not just the environment but also for its impact on land stability across the UK.
While cases of sinkholes may once have just been a brief international news bulletin, these are becoming more common closer to home as prolonged periods of unpredictable or sustained weather naturally impacts the nation’s land and homes – with cases of subsidence, landslides and even coastal collapses on the rise.
From clifftop homes crumbling into the sea after intense winds, to a 35ft wide crater opening in a quiet cul-de-sac in Hertfordshire following a storm, Brian Poole, Senior Geologist at Mining Searches UK argues that the relationship between weather and land stability is now a key concern for today’s home and land owners, and if ignored could prove to be a costly, irreversible mistake.
Many scientists argue that the UK’s climate will change due to global warming, and while these changes may appear in various forms, dependent on location, the common themes are that temperatures will rise, rainfall will generally increase, some areas will become more drought-prone, sea levels will rise, and the frequency and severity of weather events, such as storms and flooding will increase.
In turn this will impact land, with weather acting as a vital component in influencing overall land stability, as well as the safety of structures and homes, with even slight changes having the potential to cause damage – from water and air, to fluctuating temperatures.
Water is a chief agent in weathering, and from waves smashing into cliffs on the coast, to dissolving limestone or shattering rock, it is one of the Mother Nature’s most powerful weapons. High winds, bad storms and rain which batter the UK’s coast have the power to reduce a coastline by hundreds of metres in a matter of hours, destroying anything which lies in its wake in the process.
Increasing amounts of water in soil will weaken its overall strength, and if compromised may cause landslides or severe erosion, putting properties at risk of total or partial collapse – even those not located near coastlines. Many sinkholes and cases of subsidence (the movement of ground beneath a building) are also triggered by the effects of water, including leaking drainage pipes, which can soften the ground beneath property foundations.
In some areas, old mine workings and wells can also be destabilised, with water weakening the excavations or adjacent rock underground, causing these to collapse and create sinkholes – ranging from just a couple of feet in length, to swallowing whole sections of buildings or roads.
With the summer of 2018 the hottest on national record, it’s just not water which can impact the stability of land and homes, with lengthy periods of warm weather drying out and changing the composition of soils, particularly those which are clay based. When these soils shrink or swell, properties in close proximity can also change, destabilising and even moving in response to the land changes occurring beneath them.
Wet and dry weather can be a lethal combination, with a 20-metre section of cliffs in Hampshire falling into the sea last year, after a scorching summer meant the land was unable to cope with the added weight of rainfall – putting the lives of nearby homeowners at severe risk. Rain falling on dry, or baked, areas of land, can also cause flooding, with water running off the baked surface rather than being absorbed into the ground naturally.
Signs of danger for land and properties vary, from cracks appearing in a structure – especially around doors and windows – to unusual land changes emerging such as dips, troughs and bulges in the landscape. Changes in shapes of slopes, or water coming from the ground where none has been before are also early warning signs, and it is key that these are identified and examined quickly to prevent potential damage.
Insurers claim there is often a surge in claims following hot summers, and it’s vital that land home owners remain vigilant, as by the time a significant problem is noticed, it can prove to be expensive to put right. The first step in addressing any land stability issues should be employing the expertise of a ground stability, consultant or engineer, as well as contacting your insurer – particularly if damage to a structure is already evident.
For homes in historic mining areas, ensure the property and surrounding land is thoroughly assessed by mining experts, who will be able to accurately assess any risks or stability issues posed from old workings which could impact the land above.
For most homeowners, it is unlikely that their properties are risk of being swallowed by a sinkhole, however there are also several preventative measures which can be put in place by homeowners to ensure a property is more weather resistant, including keeping drainage clear of debris, and using vegetation, such a trees or shrubs, to offer some protection to soil.
With climate change set to continue to be an increasing issue, it’s evident that home and land owners understand how even the slightest changes in weather could negatively impact a property, ensuring that appropriate measures are in place to not only protect a structure, but also the lives of occupants.