• GILBERT P. BAYORAN
The Department of Environment and Natural Resources (DENR) attributed the recent landslides and flashfloods in central Negros, which brought down trees and boulders upon several communities at the slope of Mt. Kanlaon and affected almost 800,000 individuals, to the 10 hours of nonstop rains before the landfall of Typhoon Tino, which loosened the compactness of the soil.
Though the forest cover of Mt. Kanlaon Natural Park has increased significantly, the flooding in towns and cities at the slope of MKNP was also attributed to the fact that large portions of its land cover is composed of annual and perennial crops, grassland and open barren areas that cannot hold large amount of torrential rains, said Charlie Fabre, regional executive director of DENR-Negros Island Region, in his consolidated assessment report on the damage within MKNP affected by Typhoon Tino, as of November 14.
Regarding the flashfloods that cascaded from the upper portion of MKNP to the low lying areas of La Castellana and La Carlota City in Negros Occidental, as well as Canlaon City in Negros Oriental, Fabre said their ground assessment team found no indications that the trees carried down by severe flooding were illegally cut, as the affected local government units and communities to have suspected that illegal logging was involved.
The uprooted trees and vegetation along the riverbanks and creeks downstream of Mt. Kanlaon were brought down by severe flooding, he added.
DENR also reported that it has initially inventoried 12,636.88 board feet of uprooted lauan, toog, nato, sangil, and mahogany trees along the Bagacay Creek aloe in Brgy. Biak-Na-Bato in La Castellana, Negros Occidental, as of Nov. 13
Landslides were also noted along the Twin Falls in Sitio Guintubdan, Brgy. Ara-al, La Carlota City, Negros Occidental, and soil erosion were also observed due to severe flooding in rivers of San Miguel and Nagasi barangays in La Carlota City; as well as Ibid, Bagacay and Talaptap Creeks in barangays of Biak-Na-Bato and Cabagnaan in La Castellana, according to DENR reports.
The ground assessment team ascertained that flash flooding in Canlaon City, Negros Oriental during Typhoon Tino was caused by a combination of torrential rainfall and the presence of volcanic debris (lahar material from its several eruptions, prior to the typhoon) on the slopes of Mt. Kanlaon, Fabre further said.
He added that the excessive rainwater eroded and washed away the loose volcanic materials, transformed into fast-moving, dense currents of mud and debris (lahar), cascaded down the volcano’s gullies and major river channels.
The flooding with lahar and boulders in Canlaon City during the typhoon is connected mainly to the local government unit’s reliance on large vegetable production from its upland areas within the MKNP, which makes it particularly susceptible to climate adversities, Fabre also reported.
The primary relationship is one of extreme vulnerability, where heavy rainfall typical of a typhoon, quickly turns the cultivated uplands into a source of destructive floodwater, mud and debris, devastating the same agricultural base that the LGU relies upon, the DENR-NIR regional director added.
As of November 16, the Office of Civil Defense-NIR reported that deaths due to Typhoon Tino also rose to 107, with 63 missing, while 153 were injured.
A total of 12,633 houses were destroyed, with 99,081 partially damaged, according to reports of the Negros Occidental Provincial Disaster Risk Reduction Management Council.*
