Nile Delta and Egypt from Google Earth
The story begins with the story of the farmer Maged Shamdy, and his perceived fate.
"We are going underwater," the 34-year-old says simply. "It's like an occupation: the rising sea will conquer our lands."
Maged understands better than most the menace of coastal erosion, which is steadily ingesting the edge of Egypt in some places at an astonishing rate of almost 100m a year. Just a few miles from his home lies Lake Burrulus itself, where Nile flower spreads all the way out to trees on the horizon. Those trunks used to be on land; now they stand knee-deep in water.
Maged's imperial imagery may sound overblown, but travel around Egypt's vast, overcrowded Delta region and you hear the same terms used time and again to describe the impact climate change is having on these ancient lands.
The only problem is that the rest of the story documents how it is everything but climate change that is causing the problem – which doesn’t of course stop the author of the piece, Jack Shenker, from making the claim. So let me, as I did for the Bangladesh Delta, explain, with the aid of the odd peer-reviewed journal article, what is causing the problem – it isn't climate change - but in a word or four it comes down to overpopulation and the Aswan High Dam.
Let’s start by explaining how a delta system works –whether in Egypt, Bangladesh or Louisianna. The delta lies at the seaward end of a long river that picks up eroded soil carried into it from its feeding and surrounding tributaries, or eaten away from upstream by its own passage. Seasonally the river floods over the delta, and in so doing, as the water slows, it deposits soil on the surface of the delta. You can actually see effects of previous climate change by the changing nature of these sediments. In the case of the Nile, the floods come about following heavy rains in the Ethiopian highlands and Sudanese basin typically in July. August and September. Lands could be flooded to a depth of up to 5 ft, and would be inundated for about a month and a half. In that time the sediment in the water would settle out as silt, the water would flush out any residual salts in the soil, and would prepare the soil for the subsequent planting of crops. This process has provided fertility and water to the Delta for thousands of years. On average the rains in the headwaters of the Nile removed around 0.2 mm/yr of soil and this was deposited in the Delta to an average thickness of around 1 mm/year. Interestingly across the Mediterranean at Venice, Day et al showed that this type sedimentation is anticipated to provide enough land build-up over the next 100 years to mitigate even the sea rise anticipated by the IPCC at some sites.
However, as the article notes, in 1970 the High Dam at Aswan was built, and this captures all the Nile sediment (between 40 and 132 million tons a year) which is now filling Lake Nasser behind it. Although, with the Lake being some 300 ft thick, and 500 miles long, it may take a long time to do so. But now that fertile material is denied the Delta.
So that is the first part of the problem. The second part is that the sediment of a delta will normally compact over time, forcing water out of the lower members, and thus gradually lowering the top of the overlying surface. Where the land is regularly flooded that sinking is matched by the new soil that floods over it, but it is now about 40 years since the soil stopped flooding over the land, and the amount of soil missing is becoming significant. Hence, as the quote above notes, the gradual sinking of the trees into the water of the lake.
The lowered land levels also make the land more vulnerable to sea erosion. Smith and Kader showed that this can be tied to the reduction in sedimentation.
Although coastal erosion is a serious problem along the Egyptian Mediterranean Coast, it is localized at specific areas. These areas have undergone slow to moderate erosion since the turn of this century as a result of natural decrease of the River Nile flow and as a result of increased number of structures across the Nile. In a post High Dame phase, these areas eroded at accelerated rates (3-5 times the rates before the Dam).
Lake Nasser from Google Earth – at the other end of Egypt (the yellow line is the border) The High Dam is at B, and this used to be Nubia.
And to get back to the original article for the remaining problems
Today, however, Nile water barely reaches this corner of the Delta. Population growth has sapped its energy upstream, and what "freshwater" does make it downriver is increasingly awash with toxins and other impurities. Farmers such as Maged now essentially rely on waste water – a mix of agricultural drainage and sewage – from the nearby town of Sidi Salim.As the article itself notes the increased population is taking the water that used to irrigate the lower parts of the Delta. This has nothing to do with climate change (except in that the milder conditions of a Warming Period has historically led to population surges) But that doesn’t stop the charge being made.
The result is plummeting fertility; local farmers say that whereas their fathers spent just a handful of Egyptian pounds on chemicals to keep the harvests bountiful, they now have to put aside between 25 and 80% of their profits for fertilisers just to keep their crops alive.
Experts believe the problem is only going to get worse. "We currently have a major water deficit in Egypt, with only 700 cubic metres of freshwater per person," explains Professor Salah Soliman of Alexandria University. "That's already short of the 1,000 cubic metres per person the UN believes is the minimum needed for water security. Now, with the population increase, it will drop to 450 cubic metres per person – and this is all before we take into account the impact of climate change."
Much before any problem that might be related to climate change shows up, Egypt has a much larger problem, which is the root cause of the above, and which the article points out
With Egypt's present-day population of 83 million set to increase to more than 110 million in the next two decades, the seemingly unstoppable spread of bricks and mortar over the soil is both the most visible symptom of the country's demographic time-bomb and an inevitable response to it.Perhaps that should, more logically, be addressed first?
Ah, well, enough said.