2012 Bududa Landslide, Eastern Uganda

It was very sad to read last week of another large landslide on the slopes of Mount Elgon, in eastern Uganda. Heavy rains resulted in a large landslide sweeping away three villages, and burying an estimated 70 people.This area of Uganda has been hit by other landslides in recent years. In March 2010 an estimated 350+ people were buried by a large landslide, and in August 2011 a landslide killed an estimated 24 people.

These articles proposed a series of measures that should be considered in order to reduce the risk of further disasters: 

1) RELOCATION: A thorough and detailed examination of the Mount Elgon area to determine the areas at greatest risk of landslides. Those at greatest risk should be relocated. The Governments plans to relocate over half a million people have proved to be slow and unrealistic, but some relocation must occur to avoid further serious tragedy. 

2) INCREASED SUSTAINABLE FARMING: Working with communities to encourage a more sustainable farming method in the region, reducing deforestation, undercutting of slopes and increasing natural drainage. There are significant concerns that over-farming on these slopes is increasing soil erosion, reducing natural anchorage and thus continually increasing the vulnerability of these slopes. 

3) ENGINEERING SOLUTIONS: Improving draining of the slopes and toe weights at the foot of particularly vulnerable slopes to increase stability. In addition some instrumental measurement of the slope condition could provide valuable information.

A holistic, multi-faceted approach is essential, as all three of the above have their challenges and limitations. Many people do not want to be relocated, as the slopes of Mount Elgon have good, fertile soil. Compulsory relocation has its challenges, and so there must also be investment in training for farmers - relating to reducing soil erosion and deforestation, and improving drainage. Possible engineering investments should also be considered. Without some form of action the images that we have seen in the past week are likely to be seen again and again.

As Dave Petley has written on The Landslide Blog, this has not been the only landslide recently. There have been significant landslides in Bangladesh and India as well, with a number of fatalities, injuries and missing people.

Interview: Edward Joy (PhD Student)

Collecting market samples for 

composition analysis in Malawi

(Photo courtesy of Edward Joy)

In a first for the GfGD Blog, today we are publishing an interview with Edward Joy, a first year PhD student working on a project in Malawi that is combining agriculture and soil research to address malnutrition. The project is a collaboration between the University of Nottingham, the British Geological Survey and the Malawian Ministry of Agriculture…

Edward, thank you for agreeing to share some of your work with the Geology for Global Development blog community. Perhaps you could start by telling us a bit about your background and what you did before starting your PhD…

Thanks Joel for this opportunity to discuss our work. I read Human Sciences at New College, Oxford before completing an MSc in Agriculture and Development at Reading University. Agriculture is about crop and soil science, but it’s also about communities, societies and cultures, so the fact that both these courses are interdisciplinary has been very useful for my PhD. Between my MSc and PhD I worked for six months on a Permaculture farm in Konso, Southern Ethiopia, which taught me a lot about subsistence farming in a dry-land area, including the practical difficulties and the way individuals, households and communities cope.

Your PhD is looking at various ‘agricultural interventions to address dietary mineral deficiencies’ – Could you expand a little on what that means and what the project you are working will examine?

The challenge we have set ourselves is to examine how agricultural systems can be adapted to optimise the supply of minerals to a population. Minerals such as calcium, iodine, iron, selenium and zinc, are essential for human health. Dietary supply of minerals depends on what crops/livestock are eaten, and on the soil. Other important factors include cooking method and health, particularly diarrhoeal diseases. In Malawi, our case-study country, the diet is predominantly maize-based. Due to its crop physiology, maize is good at providing energy (and some minerals such as magnesium), but is not as mineral dense as vegetables, fruit, fish or meat. When your diet consists of maize porridge 2-3 times per day and little else, you’re likely to suffer mineral deficiencies.

Native Selenium (USGS)

So one agricultural intervention is to promote dietary diversity. See this article for example. Another option is to try to increase the mineral content of crops, through crop-breeding, fertilisers or soil management. So far our project has looked mainly at selenium (Se). There’s evidence to suggest that Se deficiency is widespread in Malawi. Se has many functions in the human body, including in thyroid hormone metabolism, antioxidant defence and the immune system. The transfer of Se from soil to maize is dependent on soil pH – at low soil pH, Se is highly unavailable to the maize root. Our research in Malawi has found that women living in villages on low (c.4.5) pH soils have poor Se status, whereas women living on high (>6.5) pH soils have a generally healthy Se status. This shows that soil mapping can be a useful tool for estimating variation in dietary mineral supply.

Cassava grown on dark Vertisol –

 Is the mineral composition different 

to cassava grown on common red soils?

(Photo courtesy of Edward Joy)

We’re now working to expand our dataset to look at a wide range of crops, and see how their mineral content varies spatially and according to the soil. I will also conduct field trials next year in Malawi, adding lime to maize in order to test how increasing soil pH alters maize grain concentrations of multiple minerals, and whether it might be a feasible nutrition strategy for particular soils types or under certain contexts, such as locally available lime sources.

Average population Se intake is low in the UK and this is linked to low levels of Se in our soil. Population average intake has declined since the 1970s, and it’s suggested that this is because we used to import much more of our wheat (c.45%) from N America than we do now (c.15%). Soils derived from selenifrous parent material (including shales, sandstones, limestones, slate and coal series) are widespread in parts of the US and Canada. China has areas of very high Se soil concentrations, and areas of very low, leading to problems of Se toxicity (characterised by loss of hair and nails) contrasting with Se deficiency (Keshan and Kashin-Beck diseases).

I think the work on Se highlights how important it is to better understand the relationship between human health and soils. There’s a huge need for geologists’ skills in mapping and soil studies to inform agriculture and health. BGS is at the centre of this in the UK (http://www.bgs.ac.uk/gbase/AdvancedSoilGeochemicalAtlasEbook/index.html#/1/).

You’ll be travelling to Malawi as part of your research to undertake fieldwork – what made you select this country?

Soil sampling team in Malawi

(Photo courtesy of Edward Joy)

The project is a collaboration with the Malawian Ministry of Agriculture (MoA). Much of the project’s data up to now results from field work done by Allan Chilimba, who recently completed his PhD here at Nottingham and has now returned to his senior research post at the MoA. It’s a safe country, with quite good political stability. Importantly for our work, the MoA has a good structure for disseminating research through its regional Extension Planning Areas, and local agricultural advisors who regularly meet and discuss with farmers.

What skills, other than the agronomic and geological, are you expecting to need to undertake the work effectively?

Although the field trials will be conducted at MoA research stations, there remain lots of logistical challenges such as sourcing, crushing and incorporating the lime before planting and the onset of the rainy season. So I need to plan ahead but also be flexible.

  

Finally, what made you decide you wanted to do a PhD, and why this PhD in particular?

My decision to do a PhD largely depended on the project specifics including the topic, the opportunity to do in-country fieldwork, and the supervisory team. But most importantly, I think the project benefits from linking with the Malawian MoA, Department of Health, and Bunda College of Agriculture. Our discussions with them help form our research topics, ensuring that our research is relevant to their needs. We can also directly communicate our findings to them, minimising the barriers that can hinder scientific research from benefitting people.

We will be hoping to catch up with Edward and interview him again during and/or after his fieldwork, where he can share more first-hand experience of what it’s like to conduct research in a developing country and the lessons he has learnt. 

Guest Blog: Ocean Nutrients - Geoscientists Have The Right Balance

Rosalie Tostevin is a PhD student and GfGD Ambassador at University College London (UCL). Her research examines the link between ocean chemistry and the emergence of the first animal life. Rosalie has written for the GfGD blog before, about the terrible situation in central Africa regarding conflict minerals and the negative impact on communities. Today she writes about the health of the oceans, the importance of nutrient balance, and why this is relevant for communities across the world:

The chemical elements carbon, nitrogen and phosphorous are all essential components of DNA, and their availability places major constraints on the oceans’ capacity to nurture life. Nutrient limitation and nutrient pollution are both caused by imbalances in local biogeochemical cycles (cycles in which chemical elements or molecules move through biotic, e.g. biosphere, and abiotic, e.g. atmosphere or lithosphere, parts of the earth). Management of both these very modern problems will require the expertise of the geoscience community.

Nutrient-rich deep water that upwells off the coast of Antarctica is not utilised efficiently by phytoplankton, because their growth is limited by the slow supply of an essential trace element, Iron. Not all of the upwelled carbon is converted to organic matter, as it is in the rest of the ocean, and so the carbon leaks out into the atmosphere. Supplementing the diet of the Southern Ocean with iron could block this leak and help us to offset anthropogenic CO₂ emissions. But before we embark on any geo-engineering missions, we need to appreciate the complex nature of nutrient availability.

Algal Bloom of the coast of Cornwall
(Source: NASA)

In coastal regions we often have the opposite problem: nutrient pollution. Anthropogenic activity elevates nutrient levels in coastal zones, with fertiliser and animal waste being the biggest contributors. High levels of nitrogen and phosphorous can induce algal blooms, leading to oxygen-deprivation (hypoxia) and the collapse of the local ecosystem. Once damage occurs, the system may never fully recover.

Coastal zones are important because they host 25% of global biological productivity, and border more than 70% of the world’s mega-cities. Unlike global warming, this issue affects Europe equally, if not more severely, than developing nations. However, this problem is particularly difficult to manage in developing countries, where legislating against the growing use of fertiliser would stifle development, analogous to attempts to reduce carbon emissions at the expense of industrial growth. The Rio+20 conference identified nutrient pollution and hypoxia as one of the emergent problems of the 21^st century. The UNEP Manila programme recognises that many people depend on the Oceans for their health, food security and economic livelihood. They pledge to:

‘Acknowledge the large increases in the levels of nutrients such as nitrogen and phosphorus entering the world’s environment as a result of human activity, and note the severity of the environmental problems caused by nutrient excess, including eutrophication of coastal waters and oxygen depletion, and the associated damage to ecosystems, biodiversity and coastal water quality’.

Managing nutrient pollution is difficult, because often the source of the nutrients cannot be pinned down to an individual factory or farm. The nutrients enter the atmosphere, plants, groundwater and rivers, where they are cycled many times before they reach the estuary. Input to the ocean is associated with storm activity, and so is sporadic and unpredictable.

Oil Seed Rape
(Source: Petr Kratochvil)

Fertiliser controls brought in in the 1980’s led to a slight decline in nitrogen flux, but the problem has intensified again in recent years. The UK has switched to growing spring wheat, as it is more profitable, but this leaves bare soil in winter, which promotes faster nutrient flow. A surge in the farming of oil seed rape, which needs 3 times more fertiliser than conventional crops, has been driven by a demand for biofuels.

The solutions fall into two categories: damage prevention and damage management. The biggest single change we can make to prevent nutrient pollution is to reduce our meat consumption. Recent research has highlighted the additional benefits of reduced meat consumption; improved health, lower greenhouse emissions and the ability to feed an expanding population, making this a particularly relevant policy focus. In addition, we need to manage coastal systems that have already been damaged. The first step is to understand the complexity of, and coupling between, biogeochemical cycles, something geologists are routinely trained to do. We can also learn from the response of nutrient cycles to past tectonic and climatic events. For example, the effect of increasing bioturbation on nutrient feedbacks during the Cambrian Period (approx. 542-488.3 million years ago) can be assessed using nitrogen and carbon isotopes. The approach must be holistic; geoscientists are particularly adept at working with multiple component systems. This is a problem that calls upon 21^st century geologists to put their knowledge and skills to use for the benefit of coastal communities and shallow marine wildlife.