Flood alerts raised as Dolphin moves inland

Extreme heavy rainfall persisted in parts of China on Wednesday, with authorities stepping up measures to prevent flash floods, geological disasters and other secondary hazards as Typhoon Dolphin continued to move northwestward after making landfall in eastern China.

Unlike some typhoons that dissipate rapidly after landfall, Dolphin has an extensive cloud system and abundant water vapor reserves. Its remnant circulation carried large amounts of warm, moist air northward. When the air encountered mountains such as the Taihang, Songshan and Dabie mountains, it was forced to rise rapidly along the windward slopes. As the air cooled, water vapor condensed and generated intense rainfall, greatly increasing localized precipitation and prolonging its duration, China Meteorological News reported.

In Henan province, where many of the aforementioned mountains are located, torrential rain has lashed most parts of the province since Monday. As of 10 am on Wednesday, average precipitation had reached 112.8 millimeters, while the highest rainfall of 435.7 mm was recorded at Changcun meteorological station in Changcun township, Pingdingshan city, according to Yang Hui, chief forecaster of the Henan meteorological observatory.

Heavy rain continued across Henan on Wednesday, mainly affecting cities such as Kaifeng, Shangqiu, Pingdingshan, Luohe and Xuchang, Yang said. The rainfall is expected to ease markedly across the province from Thursday to Friday.

"Given the overlap between areas that have already received heavy rain and those forecast to receive precipitation, alerts should be issued for flash floods and geological hazards in the Funiu and Songshan mountains," she said. "In central-eastern and southwestern Henan, precautions are needed against urban waterlogging and farmland flooding."

The province upgraded its torrential rain warning to the highest-level red alert early Wednesday morning and raised its flood emergency response to Level II, the second-highest level in the country, shortly afterward.

Heavy rainfall has caused waterlogging on farmland in several villages in Nanyang. Corn crops were flattened and submerged, while self-built sheds made of corrugated iron sheets and asbestos tiles sustained varying degrees of damage, according to the provincial emergency management department.

The disaster has affected 6,653 people, with 574 hectares of crops damaged. Direct economic losses totaled about 2.02 million yuan ($299,500), mostly consisting of agricultural damage, the department said.

Local authorities are carrying out drainage and waterlogging control measures while working to restore agricultural production. They have also organized evacuations and placed risk-prone sites, including flooded bridges, areas vulnerable to geological hazards and mountain and water scenic spots, under heightened safety controls.

As of Wednesday noon, 65,593 residents had been relocated and 332 resettlement sites had been opened, according to the department.

Authorities have suspended classes, business operations and nonessential outdoor activities in affected areas, urging residents to avoid deep floodwaters and evacuate immediately if their vehicles become stranded in water.

In Beijing, residents of mountain villages prone to hazards, vulnerable households, low-lying courtyards and other areas threatened by floods and geological disasters had been evacuated by 6 pm on Tuesday.

The city closed 151 tourist attractions and 157 camping sites, and suspended operations at 4,155 rural homestays and 3,357 construction sites.

According to the Beijing meteorological service, the city recorded average precipitation of 34 mm from noon Tuesday to 4 pm Wednesday. The highest rainfall, 206.1 mm, was measured at the Mujiayu meteorological station in Miyun district.

Meanwhile, South China's Guangdong province is experiencing temperatures of about 35 C due to subsiding peripheral airflow associated with Dolphin. According to the Guangdong meteorological service, thunderstorms will be frequent from Thursday to Friday, while the heatwave is expected to gradually ease.

The National Meteorological Center renewed its orange alert for torrential rain on Wednesday, forecasting heavy rainfall across extensive areas of the country through Thursday morning.