• GILBERT P. BAYORAN
The Department of Environment and Natural Resources (DENR) has attributed the recent landslides and flashfloods in central Negros to the 10 hours of non-stop rains, which loosened the compactness of the soil, before the landfall of Typhoon Tino on Nov. 4.
Floodwaters brought down trees and boulders to several communities at the slope of Mt. Kanlaon and affected almost 800,000 individuals.
In a consolidated report as of Nov. 14, DENR-Negros Island Region Regional Executive Director Charlie Fabre said that though the forest cover of Mt. Kanlaon Natural Park (MKNP) has significantly increased, the flooding in towns and cities at the slope was also due to the fact that large portion of its land cover is of annual and perennial crops, grassland, and open barren areas.
These cannot hold large amount of torrential rains, it noted.
On the flashflood that cascaded to the low-lying areas of La Castellana and La Carlota City in Negros Occidental as well as Canlaon City in Negros Oriental, the ground assessment team found no indications that the trees carried down by severe flooding were illegally cut.
Those uprooted trees and vegetation along the riverbanks and creeks downhill of Mt. Kanlaon were brought down by severe flooding, he added.
DENR initial inventory showed 12,636.88 board feet of uprooted lauan, toog, nato, sangil and mahogany trees along the Bagacay Creek alone in Barangay Biak na Bato in La Castellana as of Nov. 13.
Landslides were also noted along the twin falls in Sitio Guintubdan, Barangay Ara-al in La Carlota City while soil erosions were observed due to severe flooding in rivers of barangays of San Miguel and Nagasi, also in La Carlota City.
Similar observations were reported along Ibid, Bagacay and Talaptap Creeks in barangays of Biak na Bato and Cabagnaan in La Castellana.
According to the report, the ground assessment team ascertained that flashflooding in Canlaon City was caused by a combination of torrential rainfall and the presence of volcanic debris on the slopes of Mt. Kanlaon.
Fabre said the excessive rainwater eroded and mobilized the loose volcanic materials, with water transformed into fast-moving, dense currents of mud and debris, cascading down to the volcano’s gullies and major river channels.
The flooding with lahar and boulders in Canlaon City during typhoon is connected mainly to the local government unit’s reliance on large vegetable production from its upland, with a large portion within the MKNP, which makes it particularly susceptible to climate adversities, he added.
“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 also the very agricultural base the local government unit relies upon,” the report further said. | GB
