Damaged Road in Kaohsiung Submerged by Recurring Mudslides 高雄桃源土石流如海浪頻現 場面驚人

Repairs are currently underway in Kaohsiung's Taoyuan mountainous region, as consecutive days of heavy rain triggered mudslides and cut off its access to the outside world. In the meantime, mudslides kept happening during the past week, which complicated the mission and put the workers' lives at risk.

Mudslides down like sea waves and collects in a pile. This mudslide was witnessed by the Directorate General of Highways on Aug. 16. Mudslides are so frequent in Kaohsiung's mountainous area that they happened every day from Aug. 11 to Aug. 16. Some even occurred without rain. Soil and Water Conservation Bureau statistics show that this recent bout of rain has washed away 11 million cubic meters of soil and rocks, with another seven to eight million cubic meters situated at the upper reaches of Yusui River.

Shieh Chjeng-lun, Professor, Dept. of Hydraulic & Ocean Eng., NCKU: “The rain that triggered the mudslides wasn't very much, only 20 to 30 millimeters during six hours. That's not considered to be very much. There was also one time when it wasn't raining, but there was a mudslide because water from a tributary kept coming in. It's very unstable.”

While workers are trying to restore the access of the road, scholars are against a hasty repairment, as the circumstances are still risky for road users. They advise using other roads. The DGH has increased personnel numbers at the upper reaches and procured buzzers to increase safety.

Chen Cheng-wei, Director, Jiasian Const. Sect., 3rd Maintenance Office, DGH:” We have increased the number of personnel monitoring the upper reaches. With regards to personnel and machinery for repairs, we're increasing the number of emergency evacuation routes. We're also procuring buzzers to be used on-site.” 

The DGH said the Southern Cross-Island Highway is the most geologically unstable stretch of road, especially between the section from Qinhe to Fuxing. They will take the scholars' suggestion to bypass the section near Yusui River at the moment and divert traffic towards. For the disconnected villages, National Airborne Service Corps helicopters delivered 1,200 kilograms of supplies to mountaintop areas that remain inaccessible. The NASC also transported three patients and two family members to Kaohsiung for medical treatment

滾滾泥流像海浪一樣往下游推擠，這是16號傍晚，公路總局紀錄到的土石流，公路總局統計，山區土石流頻繁出現，11號到16號，天天都有土石流，有時沒下雨也發生，水土保持局統計，這波雨勢沖刷1100多萬立方公尺土石量， 玉穗溪中上游還有700萬到800萬立方公尺土石量留在河道中上游。

成大水利及海洋工程學系教授 謝正倫：「誘發土石流的雨量也都很小，6小時才累積了20幾毫米、30幾毫米，這個都很小。那有一次甚至沒有下雨，只是因為支流的這個水一直灌進來，也能發生土石流，所以它是非常不穩定的。」

學者認為，短期內搶通便道不確定性，民眾行經也有風險，建議思考其他聯外道路，而為了安全，公路總局也將增加上游看守人力及添購蜂鳴器。

公路總局第三區養護工程處甲仙工務段長 陳正偉：「更上游的部分，來增加我們監看人員(人力)。另外在施工的人員機具方面，我們要來增加幾處可以緊急逃生的通道，另外我們會來採購現場的蜂鳴器。」

公路總局說，學者評估南橫公路是台灣地質最不穩的路段，勤和到復興這段更是整條路最複雜的區域，因此在玉穗溪沒穩定的前提下，不宜貿然進場，將朝台東端通車來努力，而山區物資部份，空勤直升機在上午出動2架次，載運共1200公斤物資上山，也後送3名患者、2名家屬回高雄市區就醫。