Brief research update

The village of Nehas Liah Bing in East Kalimantan (Borneo), I am learning, is under imminent threat of being lost almost entirely in its current physical configuration.

Siti Lung, resident of a home located a few metres from the bank of the Wehea River, told me (translation by English teacher, Adih) that prior to the palm oil plantations, the river’s edge was “far away.” A road on the other (west) side of the river crossed over to the Nehas side for which no bridge was required because people would simply walk across it (in the low season, apparently). The river was once so low that children would swing across it on banana tree branches.

The 2011 rainy season has passed, and the current width of the Wehea River appears to be about 100 - 150 metres. It is deep enough for kids to jump from bridges and not worry about hurting themselves by hitting the bottom. The story emerging from my interviews with people here and discussions with instructors and colleagues, is that prior to 1997, floods from the Wehea River occurred as intermittently as once every two to three years, or as frequently as once a year, depending on who you ask, and probably dependent somewhat on how people define the severity of the floods. However, in 1998, a year after vast tracts of land were cleared for palm oil plantations, the number of floods increased tenfold to ten to 12 a year. Siti Lung said that since palm oil plantations, all the houses on the other side of the river vanished as the banks were undercut and overwhelmed with the increasing size of the river, as did many houses on the Nehas (east side). Another nearby resident woman, Yak, put the loss of houses on the Nehas side to be about 30 houses.

A ten-fold increase in the number of floods so soon after palm oil plantations is a correlation that cannot be denied. The reason is apparent: land clear-cut for palm oil plantations could not absorb rainfall and river water volumes rose immediately, carrying topsoil with it. While deforestation preceded this in the 1970s without similar adverse flooding effects, it is apparent that during deforestation, logging companies cut trees selectively and left undergrowth in place. The remaining trees and undergrowth were apparently sufficient to absorb the rains and prevent the massive increase in river water volumes that occurred as a result of palm oil plantations. When palm oil companies cleared all the vegetation away in order to plant palm trees, rain water flowed freely into the river carrying topsoil, turning the river brown. The soil, although it appears to float in the water as it is stirred by turbulence, inevitably falls to the river bottom and causes the bed to rise. While the river volumes may not be continuing to increase beyond the immediate increases seen in the years following 1997, I can see plainly, along with anyone here, that the river is brown, when we are told it once was clear. It is no stretch to conclude that the riverbed continues to rise. This means that floods will continue to occur more frequently to the point at which the river simply overwhelms the current banks and permanently flows over the area over which most of Nehas Liah Bing currently exists.

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More later on the history of other disturbances to Nehas, and some personal notes/observations.