Today there is little doubt that human activities since the Industrial Revolution have been leading to a warming of the planet. In the UK, not only will this affect temperatures, but rainfall will be altered within our changing climate.
Four of the five wettest years on record (since 1910) in the UK have occurred in the last 16 years (2000, 2002, 2008 and 2012) and these may be a taste of what is to come. Research by the Met Office indicates that extreme rainfall events such as these are becoming more frequent as a result of climate change.
While average levels of rainfall are not expected to increase, more variable rainfall in England and Wales is one of the side effects projected as global temperature increases. In the 21st century, there will be a greater likelihood of intense rainfall events in autumn and a greater probability of summers with above average rainfall.
Sediment is an important resource, particularly in the West Country where nutrients trapped within the soils are vital for agricultural production. Sediment, however, is washed away from our land by rainfall and transported into West Country rivers, where it is a primary cause of pollution and is leading to a decline in the health of our rivers and their ecosystems.
It is critical that sediment is kept out of our rivers and retained on the land where it can bring us the most benefits.
Rainfall is a key mechanism in transporting sediment from the land and into our rivers and, in particular, it is the intensity of this rainfall that has been found to be the dominant factor in determining erosion rates. This is why we generally see a spike in river pollution levels following intense rainfall events as sediment is washed across the landscape.
As these high rainfall events become more likely, finding ways to minimise loss of this resource is fundamental.
Climate change may also present opportunities for UK agricultural production, with increased temperatures and longer growing seasons.
However, as was stressed in the recently published ‘UK Climate Change Risk Assessment 2017,’ this potential will be limited by the availability of water and quality of soils. In fact, it is stated that current agricultural activities may become unviable in some parts of southern England due to their water requirements. As a result, it is crucial that farmers adopt good management practices to prevent the quality of our soils from further declining and to buffer the effects of water deficits.
The way forward for farmers
Alongside rain, land use has a major influence on soil erosion rates and this will have the potential either to exacerbate or counter the additional soil loss from climate change.
Westcountry Rivers Trust catchment advisors have built up a huge amount of experience in finding ways to prevent the removal of sediment from the land. In many cases, small changes to the way we manage the land can play a large role in reducing sediment loss.
As part of the South West Water funded Upstream Thinking project, the Westcountry Rivers Trust offers free and confidential advice to farmers to help protect their soil and water resources. This benefits local rivers and helps to make the lives of farmers in the West Country easier, while also allowing them to save money.
If you would like to find out if your farm could benefit from the advice being offered through Upstream Thinking, please contact: 01579 372140 or [email protected]