Lasting damage: Builders of the royal Hue monuments set buildings near canals or lakes to help collect rainwater. Unfortunately, many are now blocked by waste dumped by local residents, causing flooding and damage to the buildings. — VNS Photo Phuoc Buu

THUA THIEN-HUE (VNS)— Hue's royal buildings and monuments are threatened by decay caused by the impact of climate change and a back up of water in the surrounding waterways.

The former capital has the highest rainfall in the country and often endures rains which can last for weeks at a time; the annual average rainfall is 2700mm.

This yearly deluge is now exacerbated by the dumping of waste by Hue's residents into nearby canals, blocking the circulation of water and in some cases resulting in polluted ponds.

City planners made use of natural waterways or dug man-made canals to serve as irrigation conduits to cope with Hue's copious rainfall.

However the damage to the ancient irrigation system has reduced the canals' capacity to drain water away from the monuments, resulting in waterlogged buildings.

The Hue Monument Complex Centre is now concerned about the foundations of the ancient palaces after some stood in floodwater for almost five days this season.

Further to the problem of sodden buildings, Huynh Thi Anh Van, an official from the centre, expressed her concern for the rotting structures as infestations of woodworms encroach on the buildings and start to hollow out the wooden beams.

"During the rainy season, weight on the tile roof is increased by 15-20 per cent, exerting more pressure on the woodworm- infested structures," she said.

Builders of the royal dwellings in the former capital city created double roofs to avoid heat during the summer and excess water absorption during rainy season.

The earthen tiles on the double-roof structure become heavier with the torrential rains putting the increasingly fragile buildings under more pressure.

Researches at the centre found that woodworm colonies have increased in all the wooden buildings of the complex, critically damaging their structural integrity.

Higher temperatures from climate change have facilitated the development of woodworms and other wood eating parasites, a serious concern for Hue's monument complex largely constructed with wood.

Even new wooden pillars in Thien Tho Lang's worshipping house show signs of woodworm attack despite a recent restoration project which ended only last year. — VNS