{"id":72592,"date":"2021-05-19T10:13:41","date_gmt":"2021-05-19T10:13:41","guid":{"rendered":"https:\/\/www.bgs.ac.uk\/?p=72592"},"modified":"2024-02-28T09:27:27","modified_gmt":"2024-02-28T09:27:27","slug":"six-ways-to-prepare-your-home-for-climate-change-related-subsidence","status":"publish","type":"post","link":"https:\/\/www.bgs.ac.uk\/news\/six-ways-to-prepare-your-home-for-climate-change-related-subsidence\/","title":{"rendered":"Six ways to prepare your home for climate change related subsidence"},"content":{"rendered":"\n
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Shrinking and swelling<\/a> of the ground, often reported as subsidence, is already one of the most damaging geohazards in Britain, costing the economy an estimated \u00a33 billion over the past decade. Subsidence may lead to financial loss for anyone involved in the ownership or management of property, including developers, homeowners or local government. These costs could include increased insurance premiums, depressed house prices and in some cases, engineering works to stabilise land or property.<\/p>\n\n\n\n

How does climate change affect shrink\u2013swell?<\/strong><\/h2>\n\n\n\n

Many soils contain clay minerals that absorb water when wet (making them swell) and lose water as they dry (making them shrink). Dry weather and high temperatures have been found to be a major factor in the emergence of subsidence in clay soils. However, every summer can be completely different to the last; summer 2018 had the hottest, driest June for years whereas summer 2019 had one of the wettest Junes on record. Looking to the future, warmer, drier summers and increases in annual temperature and rainfall variability are suggested for the UK. What is considered a heat wave today may be the norm in the 2050s and cool in the 2080s!<\/p>\n\n\n\n

What does the data show?<\/strong><\/h3>\n\n\n\n

The rock formations most susceptible to shrink\u2013swell<\/a> behaviour are found mainly in the south-east of Britain. Here, many of the clay formations are too young to have been changed into stronger mudrocks, leaving them still able to absorb and lose moisture. Superficial deposits, such as alluvium, peat and laminated clays, can also be susceptible to soil subsidence and heave (e.g. in the Vale of York and the Cheshire Basin). <\/p>\n\n\n\n

Clay rocks elsewhere in the country are older, hardened by burial deep in the Earth and less able to absorb water. In some areas (e.g. around The Wash and under the Lancashire Plain) they are deeply buried beneath other soils that are not susceptible to shrink\u2013swell behaviour.<\/p>\n\n\n\n

By combining the BGS GeoSure<\/a> dataset and applying the UK Climate Projections (UKCP) scenarios for rainfall and temperature changes in the UK for the next century, maps have been produced for Great Britain showing areas with varying vulnerability to shrink\u2013swell and thus subsidence in the future due to climate change. The maps show that areas with clay soils that shrink and swell with changes in moisture are going to become increasingly susceptible in the coming century and beyond.<\/p>\n\n\n\n

The BGS GeoClimate UKCP18<\/a> datasets show an obvious increase in the amount of shrink\u2013swell potential across the south-east of England, due to climate change. Of particular interest are the clay-rich formations that are currently of low-moderate susceptibility. Buildings on these rock types might not have the robust foundations suitable to withstand subsidence hazard. <\/p>\n\n\n\n

How might this affect my home?<\/strong><\/h3>\n\n\n\n

As reported by the Association of British Insurers<\/a> (2018), the effects of subsidence in a property can usually be seen as cracks in walls that:<\/p>\n\n\n\n