The 29th edition of the Kalgoorlie event was scheduled to be held on August 3-5 at the Goldfields Arts Centre, but will now be held on October 12-14.
Walker said the change in schedule was the responsible action to take given health and safety concerns and the increasing uncertainty around large events.
"By moving the event out of the winter period, we believe we are allowing more time for authorities to assess information and guide our decision making," he said.
Members of the industry were consulted on the decision.
"Their full support has been provided given the measures the broader mining community has implemented and are planning to implement if necessary," Walker said.
Walker reiterated Diggers' support for the Goldfields community, resources sector and suppliers.
"We extend our special thanks to the City of Kalgoorlie-Boulder, and our loyal suppliers, who have accommodated Diggers and Dealers in their calendars," he said.
"To our sponsors, presenters, exhibitors, media and delegates - we look forward to seeing you in October and would like to thank you for your understanding and support."
Diggers 2019 featured 2,450 delegates, 50 presenters and 157 exhibitors.
This year's program will be released in April.
Professor Ian Goldin was announced as this year's keynote last month, and provided he can still attend the revised date, should be a timely presentation given his role as Oxford University professor of globalisation and development.
The coronavirus outbreak has thrown the world into turmoil, with many countries banning "mass gatherings", which can range from as little as five people up to 1,000 people.
While the mining sector's largest event, the PDAC Convention in Toronto, went ahead two weeks ago with 23,144 people in attendance, it's likely to be the last conference for the foreseeable future.
Paydirt's 2020 Battery Minerals Conference was due to be held the same week as PDAC on March 4-5 but was cancelled due to international travel restrictions.
Minerals & Investment Week, which includes the Global Iron Ore & Steel Forecast Conference and the Mineral Sands Conference, was due to kick off in Perth tomorrow, but has been postponed until December 1-2.
Aspermont's Future of Mining Australia and Mining Journal Select events in Sydney next week have also been postponed, as has the AusIMM's Underground Operators Conference in Perth next week.
The World Copper Conference in Santiago next week has been cancelled.
Tonight's Melbourne Mining Club Cutting Edge event featuring Lion Selection, Stavely Minerals and Aura Energy has been called off, as has the WA Mining Club's March 26 lunch featuring Iluka Resources MD Tom O'Leary.
Mines and Money Asia in Hong Kong at the end of the month has been postponed.
Vertical Events' RIU Sydney Resources Round-up and Read Corporate's Resources Rising Stars event on the Gold Coast are both still scheduled for May, though organisers are monitoring the situation.
Denver Gold Group, which cancelled next month's Zurich Gold Forum, has launched the virtual World Gold Forum to be held on April 20-23.
The virtual event will seek to replicate the one-on-one meetings, company presentations and keynote speakers that DGG's annual events in Zurich and Denver typically provide investors in the precious metals space.
"We had an idea in late January that [the COVID-19 outbreak] is not going to work out well for us and so our board authorised additional investment into our existing meeting system to be able to virtually conduct teleconference meetings with video and audio," executive director Tim Wood told MNN sister title Mining Journal.
Wood acknowledged the biggest challenge was going to be time zone as most companies were in North America.
To further emulate the traditional conferences, DGG is dispatching video teams to key mining finance cities London, Toronto, Vancouver and Denver (and possibly Johannesburg and Perth) to prerecord videos of company presentations and a roster of keynote speakers. These will then be available for download from its website in the same way company presentations filmed at DGG events have been in the past.
Wood was reticent to release details of who he is lining up for the increased number of keynote speakers for the event, although the topics are very clear.
"We will focus on the current market topicality [how COVID-19 is impacting the global economy and precious metals pricing] as well as the broader issues like ESG," he said.
The Denver Gold Forum is still scheduled to go ahead in September in Colorado Springs, as is the Precious Metals Summit a week earlier in Beaver Creek.
Precious Metals Summit organisers said a "live" event was still being planned, but they were working on contingency planning for virtual conferences and would update the status at the start of June.