Wits hydrogeologist Prof. Tamiru Abiye is a National Research Foundation-rated scholar and winner of the 2021/22 NSTF-South32 TW Kambule Researcher Award.
Prof Tamiru Abiye won the NSTF South 32 Researcher award in July 2022
Growing up poor in a rural and water-stressed region gave young Tamiru Abiye a personal view on humanity’s most pressing problem – that of securing water for people to drink. Understanding and exploring the groundwater hidden inside rocks attracted Abiye to hydrogeology.
Today, Professor Tamiru Abiye is a National Research Foundation-rated scholar and winner of the 2021/22 NSTF-South32 TW Kambule Researcher Award.
Abiye has spent some 33 years in the field of hydrogeology, which is the area of geology that deals with the distribution and movement of groundwater in the soil and rocks of the Earth’s crust. The last 15 years of Abiye’s scholarship has focused on human capacity-building. By training master’s and doctoral-level students to conduct groundwater projects, he aims to address water-related challenges in communities across Africa. In South Africa, where climate change, water pollution, and increasing populations challenge water security, his research and capacity-building activities focus on groundwater as both solution and economic opportunity.
Out of 26 public universities in South Africa, only five offer hydrogeology at undergraduate and honours levels and accept master’s students for the MSc by dissertation. However, Wits is the only university in South Africa that offers MSc in Hydrogeology by coursework and research report, which since 2015 has facilitated the enrolment of students from diverse backgrounds.
“Before my arrival at the School of Geosciences, there was no MSc programme dedicated to hydrogeology. Since I started the programme, the annual intake now ranges from 8 to 13 students. Of my students that have graduated so far, 94.4% are black Africans with a female proportion of 27.1%,” says Abiye, who so far has supervised over 115 MSc and doctoral students who are capable of conducting groundwater projects across South Africa and Africa.
Abiye’s research has also identified cancer-causing, radio-active elements and toxic metals in the groundwater used by communities in gold and coal mining areas. His research revealed the sources of the chemical element radon – the inhalation of which causes lung cancer – present in radioactive water from mines in Johannesburg as well as from building materials made from tailings (these are the materials left over after the process of separating the valuable fraction from the uneconomic fraction of an ore).
“South Africa needs qualified manpower with high-level skills to address complex water supply problems through research-based solutions – this is the focus of my research,” says Abiye. “Water insecurity as a result of poor water resource management provokes protest and conflict. Skilled hydrogeology graduates can help improve water management and thus contribute to sustainable development.
Discoveries of aquifers—underground earth formations that hold water—often create excitement around their ability to ease water scarcity in a region.
For instance, about 10 years ago a large aquifer was discovered in Kenya’s Turkana region. This is one of the hottest, driest parts of Kenya and it frequently suffers from drought. The government claimed that the aquifer could supply the entire country with water for 70 years. More recently, the US announced the discovery of five aquifers in Niger, one of Africa’s most water scarce countries, containing over 600 billion cubic meters of water. To put it into perspective, Egypt’s current water demand is 114 billion cubic meters of water per year.
These are welcome announcements. Due to a changing climate and the increasing demands of a growing population, many of Africa’s surface water resources—such as dams and rivers—are under strain. They’re being overused and slowly depleted.
Alternative water sources, like aquifers, need to be explored. Based on Africa’s geology we know aquifers are highly prevalent across the continent. But, as a groundwater and aquifer expert, I want to highlight that they’re not always going to help address water scarcity. For instance, early research findings deemed Kenya’s Turkana aquifer water unfit for use due to high salinity.
It’s important to bear these challenges in mind so that expectations can be managed. It is also useful for planners and governments, as they need to think of other ways around the water scarcity problem.
Africa’s aquifers
The volume of groundwater that’s held in African aquifers is estimated to be 0.66 million km³. This is more than 100 times the annual renewable freshwater resources stored in dams and rivers, and 20 times the freshwater stored in Africa’s lakes.
The size and shape of an aquifer is based on the body of rock beneath the Earth’s surface. Some can be in the form of caves and hold water on a large scale. Some can range from a few meters thick to hundreds of meters with multiple layers. Aquifers can also extend for many kilometers or be localized in certain areas.
Water gets into these aquifers in different ways. Some are filled by new rainfall, others hold old, or ancient, rainfall. In Africa, most are found less than 50 meters below the ground’s surface.
Many of Africa’s aquifers are spread across country borders, meaning countries have to share the water resource. The largest volumes of groundwater in Africa are found in large aquifers in Libya, Algeria, Egypt and Sudan.
There are various ways to tap into aquifers, including hand-dug wells, drilled wells and boreholes, and natural springs.
Tapping into the groundwater
Some countries have already taken steps to tap into aquifers.
South Africa has two massive aquifers. The largest stretches from Cape Town to Gqeberha, a city 750km away. This geological formation covers a surface area of 37,000km² and ranges in thickness from 900 meters to 4,000 meters. The other big one is the Cape Flats aquifer. It is estimated that by 2036, almost R5 billion (about US$274 million) will have been invested to tap these aquifers. They will yield about half of the amount of water in the Berg River dam, which provides almost 20% of the City of Cape Town’s supply.
Another large aquifer on the continent, containing only ancient trapped water, is the Nubian Sandstone in North Africa. It covers about 2 million km², and spans Libya, Egypt, Sudan and Chad. It contains more than 150,000km³ of groundwater—more water than the Nile River discharges in 500 years. The countries it spans are tapping into the aquifer and have agreed on its fair use.
Libya has undertaken the Great Man-Made River project to pipe water hundreds of kilometers from the Nubian sandstone to the coast by means of gravity flow.
Challenges in using aquifers
But aquifers aren’t a silver bullet. There are many factors to consider when using them as a water source.
Distance
The distance between the aquifer and where the water is needed can be an obstacle. In some places in Africa, this distance is covered by women carrying buckets and walking for many kilometers. The construction of pipelines and infrastructure can be costly.
A related challenge is the depth required to drill for groundwater, which can incur great costs. A type of X-ray is done of the surface to confirm whether there are groundwater resources worth exploiting, and then there’s the expense of a drilling rig.
Water quality
Water quality in an aquifer isn’t always good. Sometimes it’s polluted by human activity; sometimes the water takes on characteristics of the surrounding material in the ground.
An example is outside Gqeberha, which has one of the largest drilled wells in the Southern Hemisphere. It yields about 100 liters per second. Unfortunately the iron content of the water is above the required standards. It has to be treated before it is drinkable.
This article availed via Wits newsletter.
Picture: The Nature Conservancy