Floods swamp China's south, spark extreme weather fears

Floods have swamped cities in southern China's densely populated Pearl River Delta following record-breaking rains, sparking worries about the region's defences against bigger deluges induced by extreme weather events.

Since Thursday, Guangdong province has been battered by unusually heavy, sustained and widespread rainfall, with powerful storms ushering in an earlier-than-normal start to the region's annual flooding season in May and June.

In Qingyuan, a relatively small city of four million, residents counted their losses.

"My rice fields are fully flooded, my fields are gone," Huang Jingrong, 61, told Reuters.

Huang was sheltering under an overpass with other farmers from his village, alongside an assortment of personal belongings, including a washing machine.

"I won't be making any money this year, I will be making losses," he told Reuters, estimating the cost at about 100,000 yuan ($A21,451).

"What can we do? We won't get reimbursed for our losses."

Over the weekend, waterways in Guangdong overflowed including the river near Huang's village, where floodwaters have reached the second storey of houses after washing out paddy and potato fields.

In other parts of Qingyuan, rescuers tackled neck-high waters to extract residents including an elderly lady trapped in waist-deep water in an apartment building.

Others remained on the upper floors of their houses, waiting for the water to recede as friends delivered food by boat.

Precipitation records for April have been broken in many parts of Guangdong, with the cities of Shaoguan, Zhaoqing and Jiangmen to the west and north of Guangzhou also half-submerged in flood-waters.

The downpours have killed four people and 10 others remain missing in the province as of Monday, state-owned Xinhua News Agency reported.

Across the province, 36 houses collapsed while 48 were severely damaged, resulting in a direct economic loss of nearly 140.6 million yuan ($A30.2 million), Xinhua reported.