The author of the Outlander novels will receive a special award from Scotland's tourism body to recognise the effect her work has had on visitor numbers.

Diana Gabaldon will be presented with International Contribution to Scottish Tourism award from VisitScotland at the Scottish Thistle Awards in Edinburgh on Thursday.

It comes as research revealed attractions used in the TV adaptation of her books have seen a 67% upswing in visits since 2013.

Doune Castle, which doubles as Castle Leoch in the series, has seen the largest surge in visitor numbers - 226.5% in the last five years, from 38,081 to 124,341 - followed by Blackness Castle (181.7%), which features as Black Jack Randall's headquarters, and Glasgow Cathedral (66.8%), which was used as the set for a French hospital.

As part of the research, all Scottish visitor attractions were surveyed to discover how screen tourism and the Outlander effect have impacted on their business.

Almost all respondents considered screen tourism - also known as set-jetting - as positive for the industry and a fifth of attractions near filming locations said they saw an increase in visitors.

The findings also reveal that the dedicated Outlander page on visitscotland.com was the fifth most popular page on the site in the time between the broadcast of seasons three and four of the series - with Scotland's standing stones, castles and ancestry among the most popular link clicks.

Ms Gabaldon said: "I'm deeply honoured, and so pleased, at being given the Thistle Award.

"To be quite honest, I chose Scotland as the setting for my first novel because of a man in a kilt, but upon looking into things more deeply, was enchanted to discover a country and a people like no other, whose traditions and history are as strikingly beautiful as its landscapes."

Malcolm Roughead, chief executive of VisitScotland, added: "The impact of Outlander on Scotland has been truly extraordinary.

"It has been amazing to see the global reaction to Diana Gabaldon's stories of adventure, romance and Scottish history - and the subsequent television adaptation - and seeing it translate into visitor growth for Scotland."