By A. Paulita Roa
A DECADE ago, Cagayan de Oro started to experience heavy torrential rains that resulted in flooding. The most severe was in 2011 when over 2,000 persons died or declared missing and millions of pesos worth of properties were damaged.
Before, we, the Kagay-anon, proudly declared that our fair city was typhoon-free. It is sadly not the case today. We are not anymore surprised to learn that several areas in the city are perennially prone to floods like the city’s prime business area on CM Recto Avenue. Every time there is a heavy rain, photos of cars partially submerged in floodwaters and students of the university nearby fleeing in government trucks, are posted on the Internet. Recently, I was informed that Divisoria is not anymore spared from ankle-deep waters after heavy rain.
Although the frequency of the typhoons occurring around the world are attributed to climate change, it is still important for us to know the topographical features of our city and the northern Mindanao region. We can then, perhaps, come up with preventive measures so there will be no repeat of the tragedy the city underwent during the onslaught of “Sendong” in 2011.
The late Fr. Francis C. Madigan S.J. described Cagayan de Oro as a hilly region whose best soil is found along the coastal plains and river valleys (1968). However, there is a book titled Philippine Island World (Wrenstedt and Spencer 1967) that contains a more extensive description of the regional geography of northern Mindanao and Cagayan de Oro in particular. For starters, it described the general landscape of Mindanao as having extensive lowlands that are supported by major river systems, and that vulcanism played a major role in forming the landscape of the island as evidenced in the long and deep embayed coastlines with a large peninsula and protected bays (p.503).
We know that there are several volcanoes in Mindanao, foremost of which are the seven volcanoes Camiguin province. Years ago, during the archaeological excavation that was conducted by the team from the UP-Archaeological Studies Program at the Huluga open site in Taguanao, a thick layer of volcanic ash was discovered between two cultural layers in the trenches.
A cultural layer represented a period when people inhabited a given area while the layer of volcanic ash could mean that it was a time that the area was barren.
With the aide of a GPS, it was duly noted that Huluga is around 60 km from Mt. Kitanglad of Bukidnon, known to be an extinct volcano. Since there are no records of a volcanic eruption in the past that severely affected the city, it could mean that the eruption from Mt. Kitanglad happened thousands of years ago. In my archaeo-geology class, we learned that if a volcano did not erupt within 10,000 years, then it is no longer considered active. But we never know how many thousands of years ago this mountain last erupted.
The topographic features of northern Mindanao is described as a narrow strip of densely populated lowlands located along the north coast. The narrow strip borders on the low foothills and rarely exceeds 15 miles in width. The larger and more important lowland areas lie along the Cagayan, Cugman and Iponan rivers. While the smaller areas are located along the heads of the Macajalar and Gingoog bays. Further inland are the higher uplands of the Bukidnon and Lanao plateau and are composed of mostly decayed volcanic materials and metamorphic rocks like slate and quartzite. (to be continued)