Elizabeth Truss is Secretary of State for the Department of Environment Food and Rural Affairs and MP for South West Norfolk.

By adding nearly 200 square miles to the Yorkshire Dales and Lake District National Parks, we are creating an almost unbroken expanse across 80 miles from Ravenglass to Richmond.

My decision to expand the two Parks, which was announced earlier today, is a recognition of how much we value wild places such as the Howgill and Orton Fells in Yorkshire, Whinfell Common and much of the Lyth Valley in Cumbria. They are landscapes of unparalleled beauty, and they are at the heart of what it means to be British. Now they are secure for future generations.

When I was growing up in Leeds, our family were avid hill-walkers and we often went for trips in the Lakes and the Dales. Although we sometimes got lost or stuck in bogs, it is the joy of the open space that is unforgettable. The Lake District was the birthplace of Britain’s rural tourism. It is two centuries since Wordsworth published his Guide Through the District of the Lakes for the visitors who followed in the path of the Romantic poet.

The National Parks have been a triumphant success, managing landscapes for their beauty and value to nature while creating thriving local economies. In England, the Parks welcome 90 million visitors a year, 800,000 of them from overseas. They spend more than £4 billion, supporting tens of thousands of jobs and securing the future for these living, working landscapes and cultures.

For centuries, farming has shaped the Dales, the Lakes and other Parks such as the South Downs and Dartmoor – and farming has turned them into foodie paradises. They bring us some of the finest traditional produce, like Yorkshire Wensleydale cheese, now a worldwide export success; and Lakeland Herdwick lamb. One third of all Britain’s legally protected food names are produced in National Parks, and in England alone they are home to no fewer than six Michelin-starred restaurants.

The Parks are role models for harnessing a healthy, beautiful environment to a thriving economy and society and connecting people with nature. The volunteers who work there do superb work organising field trips for schools and organising activities like pond-dipping for insects on Dartmoor. They are great places for children to learn about everything from geology to fitness, rural history and healthy, fresh food.

The National Parks allow whole landscapes to be treated as one integrated whole, not just as a series of individual features or species. That is the approach we are adopting more widely, for example looking at not just a stretch of water but a whole river catchment. Nature does not work in silos or stop at administrative boundaries and neither should our thinking.

We will devolve decisions to people who know best at the most local level possible. It could be to farmers keeping streams on their land clean or nature organisations working with local businesses and residents to create pocket parks in towns and cities. Or it could be to all of us, whose everyday decisions can help bring about change.

People will have the tools to make those decisions. We are releasing thousands of sets of data about the natural environment, covering everything from fish stocks to flood risk and the health of our soil. The 3D landscape data we released last month has already been requested by enterprising people to predict snowfall on hills, model flood defences and create new landscapes in Minecraft.

I want to go further and use this data to value the contribution nature makes at a local level. For example, trees are worth 15 times their value in timber once you factor in our personal enjoyment, and their role filtering pollution and storing carbon. The value of nature in Britain has been estimated at a total of £1.6 trillion.

This information will be of practical use, helping us get better value for money from environmental programmes. It will be openly available to help determine where to plant trees, or to assess the impact of new building. The National Parks show that a thriving rural economy, superb local food and beautiful landscapes aren’t just compatible – they are mutually dependent.

These Parks are prize national assets every bit as much as economic infrastructure like the M25, Manchester Airport or the Forth Rail Bridge. By empowering people locally, by operating at a landscape scale and by making sure we know their value; we can help them and all of our natural wonders thrive for generations to come.