It could be citizen science. Part 3: Citizen Sediment
There is a problem with sediment in the Mekong. There soon won’t be any. That is an overstatement, but possibly not by much. Some studies suggest that sediment delivery from the upper Mekong has decreased by as much as 50 percent mainly as a result of dam construction. Attempts to predict future sediment loads in the Mekong basin are severely hampered by limited data availability. I talked with Tarek earlier today, the last day of the 3rd Mekong Forum on Water and Energy here in Hanoi, about a possible role for citizen scientists collecting sediment data.
Tarek is currently an environmental systems engineer working with ICEM, the International Centre for Environmental Management, in Hanoi, Vietnam. He is also one of the relatively few people in the Mekong who, like me, thinks sediment is becoming the hot transboundary issue.
Tarek explained, “There is some data on sediment but it’s not being shared all that well by the Mekong countries, and each agency uses different data collection methods, so it’s difficult to compare.”
There are sediment monitoring stations, but they mostly collect data on small ‘suspended’ particles, which move through the river fairly rapidly. The larger particles or ‘bedload’ particles take longer to transport and there is much less data on bedload.
“Bedload sediments are what shape the river and provide the basis for living habitats in the floodplain,” Tarek said.
I asked Tarek if he thought there might be a role for citizen scientists in helping collect such data. Tarek explained several simple technologies and methods that don’t require a lot of expensive equipment or training, “… but I can’t see the public getting terribly excited about participating,” he said.
This is a challenge for any citizen science initiative. It’s not difficult to see how some people can get excited hunting for new planets, or using online simulations to learn about nanomedicine and exploring how nanovehicles can cooperate with each other and their environment to kill tumors. But sediment?
I reminded Tarek of something he had said earlier in our conversation about Vietnam’s Ministry of Environment and Natural Resources. Part of ICEM’s Strategic Environmental Assessment included a section on sediment. So significant were the implications of reduced sediment loads to the Mekogn Delta, that the Vietnamese government went from supporting mainstream dams to calling for a moratorium. Someone in the Ministry must have been excited.
If you want to collect a lot of sediment in a short time, build a dam.
Water piles up behind a dam wall in a reservoir. It’s standing still. Even the fine sediment has time to settle to the bottom. The water that comes out the other side of the dam has less sediment. The Sesan River, for example, has 8 dams trapping sediment, so the water that flows into the mainstream carries less. As sediment particles are washed away by rainfall, they bring with them chemicals like nitrogen that nourish aquatic ecosystems and help make floodplain soil the rich agricultural land it is. The Mekong Delta, Vietnam’s rice bowl, was built up over 6,000 thousand years by the slow accumulation of sediment. Alter the flow of sediment and you are meddling with the entire riverine environment.
The general decline of sediment in the Mekong spells bad news for aquatic ecosystems throughout the Mekong environment and the Mekong Delta especially. Between sea level rise, groundwater abstraction and loss of sediment, the Delta is shrinking, and along with it, Vietnam’s food security. There are certainly a lot of people interested in those issues, so I think it might not be such a leap to get people interested in something as central to those issues as sediment. I think it might be worth a concept note.