BANGKOK — Sutopo Purwo Nugroho, who relied on science to offer fact-based explanations for Indonesia’s frequent natural disasters as the widely respected spokesman for his country’s disaster management agency, died early Sunday in Guangzhou, China. He was 49.

He was in China for cancer treatment. Indonesia’s National Disaster Mitigation Agency reported his death on Twitter. A lifelong nonsmoker, he learned he had Stage 4 lung cancer early last year.

Mr. Sutopo gained national acclaim as a straight-shooting government spokesman in times of earthquakes, volcanic eruptions, a tsunami and other natural disasters.

[Read our profile of Mr. Sutopo from last year.]

Despite his illness, he continued in his post during what he called the year of disasters, at times tweeting and taking reporters’ calls from his hospital bed.