Climate change is expected to wreak all kinds of havoc on future weather systems, with experts predicting greater and more frequent storms, hurricanes, droughts and floods. But even the darkest clouds have some silver lining, and a new study closely examining its effects on Ethiopia's Blue Nile Basin has uncovered exactly that in the form of projected increases in rainfall, which could spur greater crop yields and large-scale hydro-power projects in the region.
The idea that climate change could bring more water to the region is actually not a new one. Earlier studies that used temperature and precipitation from climate modeling have predicted that the phenomenon could boost Ethiopia's water availability by 10 percent, but according to researchers at Virginia Tech, this was leaving out some vital information.
In what it describes as a first-of-its-kind study, the team combined hydrologic models with bias-corrected and downscaled data from the Intergovernmental Panel on Climate Change to form a more complete picture of water flow at two key headwater basins in the Blue Nile Basin, which feeds as much as 66 percent of the Nile River flowing through Sudan and into Egypt.
It then looked at the predicted impact of climate change on the region over two particular time periods, 2041-2065 and 2075-2099. It says the analysis indicates that the two basins will experience increases in mean annual water flow of 22 to 27 percent, and that monsoon season will be extended by four to six weeks, potentially making growing seasons longer and perhaps allowing for two cycles of crops to be grown per year.
"It's interesting, because much of the Blue Nile Basin is well above 5,000 ft (1,524 m) in elevation, giving it pretty much an ideal climate for agriculture with low humidity, low disease and pest pressure, and potentially great water availability, which could spur development," said Zach Easton, associate professor of biological systems engineering at Virginia Tech.
But don't go firing up your six-liter V8 for the sake of Ethiopia's prosperity just yet. The study was also the first to look at the problem of sediment transport, which is a particular concern in the Blue Nile Basin where some of the world's highest erosion rates have been measured. The increase in water flow sounds like a good thing, but would also bring with it more sediment that could reduce the capacity and efficiency of dams, reservoirs and hydro-power projects.
"Greater water availability is certainly a positive outcome, but this is countered by more sediment," says Easton. "One way to combat that is through installing conservation practices on farms, for instance using cover crops and low- and no-till planting methods to make the soil healthier, more stable, and reduce erosion."
The research was published in the journal Climatic Change.
Source: Virginia Tech
