The nation this week must be prepared for the threat of torrential rain brought on by the influence of the southwest monsoon and a tropical depression system, the Central Weather Bureau (CWB) said yesterday.
Although Typhoon Guchol was not expected to directly threaten to Taiwan, the bureau said it would compound the effects of the southwest monsoon as it moves northward.
Chances of heavy rain or extremely torrential rain would be high in central and southern Taiwan from tomorrow through Friday, bureau forecaster Lin Pin-yu (林秉煜) said, adding that although afternoon showers are forecast for northern Taiwan, chances of extremely heavy rainfall in the northern and eastern regions are high as well.
Based on the bureau’s standards, “heavy rain” is classified as 50mm or more of rainfall within 24 hours, in which at least one hour in that period sees rainfall of 15mm.
“Extremely heavy rain,” as defined by the bureau, occurs when rainfall within a 24-hour period reaches 130mm. The rainfall would be categorized as “torrential rain” or “extreme torrential rain” if rainfall exceeds 200mm and 350mm respectively.
As of 2pm yesterday, Guchol was located 880km south of Okinawa. It was moving north at a speed of 24kph, with the radius of the storm expanding to 200km.
Aside from the southwest monsoon, Lin said the public has to pay attention to a tropical depression lurking near China’s Hainan Island.
“It [the tropical depression] has the potential of turning into a tropical storm,” he said. “We have to prepare for the damage it may cause because it is very close to us. It is likely it will move northeast in our direction. If the system moves close to Taiwan, the bureau would have to issue a sea alert.”
Separately yesterday, the Water Resources Agency said damage to the Jiji Diversion Weir in Nantou County from heavy rains last week was now under control and normal water supply had been secured.
The heavy rains last week flooded the Jhuoshuei River (濁水溪), causing damage to 200m of the weir’s water channel as well as to dams and revetments along the river, including the 345m Shueidiliao Dike.
Although the damage had aroused concern about the water supply in Yunlin and Nantou counties, the Central Region Water Resources Office conducted emergency pipeline engineering work and initiated the backup system to secure the water supply, the agency said.
Water Resources Agency Director-General Yang Wei-fu (楊偉甫) visited the weir’s management center yesterday. In a briefing, the Fourth River Management Office in Changhua County reported that the situation at Shueidiliao Dike was under control and subsequent repairs would be finished within two months of the flood’s recession.
Central Region Water Resources Office Director Chung Chao-gung (鍾朝恭) said the emergency pipeline connection project began on Friday and is scheduled to be completed next week so the water supply in the area would soon be secured.
Officials at the water resources office were reminded by Yang to take precautionary measures before the next wave of torrential rain.
In related news, the CWB recorded 19 earthquakes in Hualien County between 2:19am and 6:01pm yesterday, with magnitudes ranging from 3.1 to 4.7 on the Richter scale.
The epicenter of the majority of them was in the county’s Fongbin Township (豐濱), it added.