Visitors to national parks who get drunk, make noise and cause disturbances will be turfed out, the Department of National Parks, Wildlife and Plant Conservation has warned.
"We will no longer be patient with tourists who create disturbances for others, especially those who get drunk. We will immediately tell them to leave the park if they don't stop their aggressive behaviour," said Thanya Nethithammakul, chief of the Department of National Parks, Wildlife and Plant Conservation.
"People come to parks need to enjoy tranquility, not loud noise."
As the holiday season approaches, the department which oversees national parks across the country is preparing to deal with an influx of tourists.
The department expects to get increasing numbers of tourists visiting parks to enjoy the cool weather and scenic natural views.
Last year, 12.9 million holiday-markers visited national parks, generating revenue worth 2.4 billion baht.
In 2016, the department received 1.9 billion baht from tourists. Mr Thanya said he expected the revenue from tourism will continue to rise.
Yet more people lead to more problems for the department.
The department is now facing the challenge of how to have achieve a balance between making money and protecting the ecology of national parks.
In many parks, wildlife has been disturbed by holiday-markers who feed animals with processed foods. Cars have run over monkeys, and reportedly drive elephants berserk in Khao Yai National Park.
Tourists also complain of other visitors' noisy and raucous behaviour such as singing and drinking, according to the department.
A major problem is the accumulation of garbage.
The department estimated that each tourist generates 0.5 kilogrammes per day.
For example, the amount of garbage during a four-day period during the New Year celebration at Doi Inthanon National Park in 2015 was just over 70 tonnes.
As most national parks are in sites which are hard to access, such as deep forest or islands, garbage is left to accumulate.
Mr Thanya said he had ordered all national parks, especially the top 10, to set up waste management plans to deal with the flow of garbage.
National Park Office director Songtham Suksawang said the department is now seeking cooperation from visitors to not leave any rubbish inside parks through campaigns such as "Take Trash to Home" and "No Plastic Bag and Foam" in a bid to reduce waste inside the parks, including a ban on smoking on beaches.
Mr Songtham said the department will partner with the local government organisations to clean up the park while the department drafts a policy to allocate 5% of each of park revenue to support local administration and communities.
Previously, the department was working with the Local Administrative Organisation in Phangnga National Park to reduce waste from the park.
The park has introduced a ban on plastic bag use in the park's souvenir shops.