Let us walk for a moment through a region to the south of the Sahara, stretching from Western to Eastern Central Africa, which is at once ubiquitous for its rich cultural history and crippling civil conflict; today we will visit The Sudan. The name derives from the Arabic bilād as-sūdān (بلادالسودان) or “land of the Blacks” (an expression denoting West and Northern-Central Africa). The phrase “The Sudan” is also used to refer specifically to the modern-day country of Sudan, the western part of which forms part of the larger region, and from which South Sudan gained its glorious secession in 2011. The Sudan extends in a band-like manner 5,000 km long and several hundred kilometers wide across Africa. It stretches from the border of Senegal, through southern Mali (formerly known as French Sudan when it was a French colony), Burkina Faso, southern Niger and northern Nigeria, southern Chad and the western Darfur region of the present-day Sudan.
To the north of the region lies the Sahel, a more arid Acacia savanna region which in turn borders the Sahara desert to the north, and the Ethiopian Highlands in the east (al-Ḥabašah). To the south-west lies the West Sudanian Savanna, a wetter, tropical savanna region bordering the tropical forest of West Africa. In the center is Lake Chad, and the more fertile region around the lake, while to the south of there are the highlands of Cameroon. To the south-east is the East Sudanian savanna, another tropical savanna region, bordering the forest of Central Africa. This gives way further east to the Sudd, an area of tropical wetland fed by the water of the White Nile.
Many lifetimes have been spent studying the history of the Sudan, and I will not even attempt to provide a comprehensive account here, but I will say that Sudan has for millennia been the crossroads between Central Africa and the Mediterranean. Sudan as it lives today is a rich and diverse ethnic soup symbolic of the drama and intrigue of its past cultures. The northern area of the country, along with southern Egypt, was home to several ancient civilizations. The first settlers in northern Sudan date back 300,000 years. It is home to the oldest sub-Saharan African kingdom, the kingdom of Kush, which was the most powerful state in the Nile valley four thousand years ago.
Conflict between Egypt and Kush in that era culminated in the conquest of Kush by Thutmose I, but in the 11th century BC, Egypt withdrew and the Sudanese kings grew powerful again. In the 6th century, they invaded Egypt and ruled as Pharaohs uniting the Nile valley from Khartoum to the Mediterranean. The Kushites were expelled from Egypt by the Assyrians, but their kingdom flourished in Sudan for another thousand years. Kush monuments and art display a rich combination of Pharaonic, Greco-Roman and indigenous African traditions, and two are UNESCO World Heritage Sites – Meroe and Gebel Barkal. Tall pyramids, gigantic mud-brick buildings, rock-cut painted tombs, and ornately carved temples – all remain for the roaming adventurer to discover, sit silently within and dream.
Our story takes us to the city of Kassala which along with the Red Sea and Gedaref State comprise East Sudan. With a total area of 55,374 km2, Kassala State lies between latitude 34o 12| and 36o 57| East, and between longitude 14o 12| and 17o 12| North. The state shares an international border with Eritrea to the East. Nationally, it borders Red Sea State and River Nile State to the North, Gezira State to the West, and Gedaref State to the South.
Kassala is composed of eleven localities (mahaliyas) nine of which are primarily rural in composition while the two localities of Kassala Town and New Halfa are urban centers. Kassala State has an exceedingly variegated agroecological landscape with 80% flat plains, and 20% rocky outcrops and hilly terrain. The state is covered by alluvial and volcanic deposits beneath which lie clay Basement Complex and Vertisols formations which respectively, are a very poor repository for ground water and are very difficult to work with. Any water to be found in this northern area tends to be distributed along cracks in the geological formations. In contrast, the southern soil of the state is a lighter, highly permeably variety of clay soil which supports the rainfed systems of cultivation most commonly practiced in the Gash Delta region of the state.
The Gash River, is a major water supply source in the state providing around 560 million cubic meters of water per year during its months of heightened flow. It is a massive torrential stream originating from the Eritrea/Ethiopian Plateau and extending all the way to the Gash Delta within the eastern part of Sudan. The length of the river is about 110 km from the border to the end at the Delta Die. Its seasonal flow occurring mostly between June and October varies significantly from year to year, ranging from a minimum of 200 to a maximum of 1200 Mm 3/year. The Gash River carries with it a large amount of sediment, predominantly suspended load, and it is estimated that, the sediment load is between 5.5 to 13 million m3 per year. Gradual build-up of this sediment has raised the river bed by more than 2 m compared to the surrounding land of Kassala town, further exacerbating the risk of damaging floods by the river.
The Gash Delta is approximately 280,000ha of land, 180,000 of which is allotted to the Gash Agricultural Project. The remaining 100,000ha is irrigated land and makes up the Gash Irrigation Scheme and is primarily supplied by the Gash River. The Delta is completely dry during all but the flood season months, and over the last few years (1975, 1983, 1988, 1993, 1998), and most recently in 2003, 2007 and 2013, the region has been witness to devastating flash floods that wipe out whole villages and displace hundreds of thousands of people.
The literature is in agreement with regards to the major causes of these floods primary among which are; 1) increase in the river discharge due to climate change, which in its turn leads to land use change, high floods and sediment transport, 2) rise in water levels due to a reduction in water channel carrying capacity caused by structures which obstruct water flow e.g. bridges, spurs and dykes, as well as morphological changes in riverbeds and slopes, and 3) cavitation due to human and animal activity or weakening of river banks.
Inundated with flood waters during these key months of the year, farmers in the Gash Delta are powerless to respond. They simply wait for the rain to spend itself, for flood waters to recede, and for the soil to lose some of the moisture before sowing seeds. How long this process takes in any particular year is anyone’s best guess, and each year, the region sinks deeper into food insecurity because as research has shown, if a field is flooded for more than two to three weeks, crop yields are invariably lower.
While it is true that a great deal of damage has already been done, and it is almost impossible to reverse the hand of nature once she has moved it, some really smart people at the International Water Management Institute (IWMI) began to do a little bit of thinking. They began by collecting remote sensing satellite data in the Gash Basin, and on a weekly basis, they analyzed images in 5 major irrigation sections of the Gash Basin, and used the results to determine the extent and duration of flood waters. They also collected data on soil, land cover and water flow to forecast flood flows at a downstream Kassala station where inundation is particularly high. With all this information, and working with partners at the Hydrolic Engineering Center, Gash River Training Unit, and Kassala University, they used a Hydrological Modeling System and River Analysis System, to develop a prototype flood forecasting tool which works to better prepare farm fields in advance of flood events in order to mitigate damage and improve disaster agency response services.
In simple terms, this tool converts complex satellite sensor information to simple text messages which are sent to farmers informing them about the optimum use of flood water for crop production i.e. how to make the flood waters work for them. These texts also warn farmers about flood events which allows them to better prepare their fields, and gives them information on ways to mitigate flood damage by better estimating the risk of future flood events. The flood management tool is also able to predict which areas will be flooded and what communities may be displaced. Overall the technology provides a means of utilizing flood waters for irrigation purposes which in its turn has the potential to improve food production and livelihoods in flood irrigated areas.
Climate change is inevitable, whether by way of human activity, or by natural mandate. However, I think that organizations like IWMI are showing us that climate change does not necessarily have to signal the complete annihilation of human life, rather it presents us with a unique opportunity to change the way we live, and regardless of if living is in a modern flat in Addis or in the fields of the Gash Delta, we can all do our bit to ensure our sustained livelihoods, that of our children and the future of this our Africa.
Next Up: …maybe we’ll return to SAP 🙂
Bashar, K.E.- GASH RIVER FLASH FLOODS CHALLENGES TO KASSALA TOWN: MITIGATION AND RISK MANAGEMENT- http://www.rcuwm.org.ir/En/Events/Documents/Workshops/Articles/8/21.pdf
Climate Change 2014: Impacts, Adaptation, and Vulnerability– Working Group II of the Intergovernmental Panel on Climate Change (IPCC)
Eni, Devalsam I, Atu, Joy E, Oko,Comfort..O,Ekwok,Innocent (2011). Flood and Its Impact on Farmlands In Itigidi, Abi Local Government Area, Cross River State, Nigeria , International Journal of Humanities and Social Science, Vol. 1 No. 9.
USDA (1993). West Virginia erosion and sediment control handbook for developing areas. USDA. Sol conservation service: Morgantowa, W. V. West Virginia Division Highways (WVDOH) (2000). Standard specifications for roads and bridges, State Government, Charleston, W. V.