Geology for Global Development

Guest

This guest post was contributed by a scientist, student or a professional in the Earth, planetary or space sciences. The EGU blogs welcome guest contributions, so if you’ve got a great idea for a post or fancy trying your hand at science communication, please contact the blog editor or the EGU Communications Officer Laura Roberts Artal to pitch your idea.

Jesse Zondervan’s #GfGDPicks (Nov 2017): How did people in ancient times fare during climate changes? Should we use geoengineering? #SciComm

Each month, Jesse Zondervan picks his favourite posts from geoscience and development blogs/news, relevant to the work and interests of  Geology for Global Development . Here’s a round-up of Jesse’s selections for the past month:

How successful were people in the Neolithic and ancient times in adapting to climate change? Two contrasting stories emerged this month:

A new study from Past Global Changes (PAGES) suggests that abrupt shifts in climate caused by eruptions helped to trigger violent uprisings and other political upheaval in the Ptolemaic era. A more constructive message comes from the University of Plymouth, where researchers suggest we can learn from human behaviour during the last intense period of global warming.

Staying with the volcanic theme: David Bressan reports on the volcanic fatalities database published this month in the Journal of Applied Volcanology. What are the deadliest hazards associated with a volcano?

Further in the disaster risk reduction world, we see optical fibre strands underneath Stanford University used as an earthquake observatory. Meanwhile, earthquake apps bring more superpowers to your smartphone: learn how to use them in Andrew Alden’s post on the Oakland Geology blog.

I will finish with the question Anna Pujol-Mazzini poses: Could geoengineering the planet to curb climate change leave people in poor countries better – or worse – off?

A historical perspective:

Sustainable cities

Credit: Yanick Folly winner of the Sustainable Cities photo competition (http://tinyurl.com/y9jju98h)

Disaster Risk Reduction

Climate Change Adaptation

Opportunities

Check back next month for more picks!

Follow Jesse Zondervan @JesseZondervan. Follow us @Geo_Dev & Facebook.

Robert Emberson: Geomythology – Why understanding cultural traditions of landscape are important for sustainable development

Every culture has myths and legends about their native lands. Before we understood the geological forces that forced up great ranges of mountains or sculpted barren deserts, humans needed an explanation for the scale and majesty of natural phenomena. Stories of deities inhabiting volcanoes, or angry gods shaking the very ground upon which people lived, helped people make sense of disasters when tectonic forces were unimagined. Since the advent of the scientific method, and secularised science, such tales are often forgotten when we look at a landscape; why resort to a story when the facts say otherwise?

Devil’s Tower, Wyoming. Image courtesy psaudio / Pixabay

In some cases, it’s true that such stories don’t offer geologists much factual evidence about how the landscape formed. Even beautiful stories about features like the Devil’s Tower, in Wyoming, USA; the ancestral tale tells of people pursued by a giant bear; once they had reached the top of the peak, the bear could not reach them, but the scratch marks on the sides were testament to its attempts. Today, we know these are classic examples of columnar jointing. Although we might enjoy the story, it definitely doesn’t tie to the more modern understanding!

But there are some instances where we should perhaps pay more attention to myths, and particularly in the context of geology and sustainable development. While the tangible evidence of geological processes are often visible at a grand scale, it’s also true that the signals or proxies we look for to understand these processes can be very scarce. Trace fossils, or small shifts in element abundances, for example; we should take advantage of every shred of evidence we can find. As a result, some scientists have been turning to ancestral stories – in particular those about catastrophic events – for information.

Researchers have found tantalising clues about past events in mythical tales, and it seems often there is no smoke without fire. Amongst other studies, geologists have found evidence of volcanism in previously thought-dormant Pacific Volcanoes from local accounts, and evidence of giant floods in China, partly linked to tales of Emperor Yu 4000 years ago. The cultural memory of such giant catastrophes is etched into the myths told there; it seems that using these stories could help us better establish the timing and recurrence of natural disasters, allowing for improved risk analysis and development in tune with natural events.

There’s another, perhaps even more important aspect of geological myths to bear in mind for sustainable development. It’s increasingly well understood that the best approaches taken to encourage development, economic or otherwise, will differ across the world, driven by cultural differences. Development anthropologists could point to studies (e.g. see here) indicating that the definition of quality of life varies widely to suggest that a local approach would be the most sensible in approaching development, rather than assuming a standard ‘western’ approach would work everywhere.

The relationship of people to their landscape is, for the same reasons, an important variable to consider when discussing development. For example, Mt Machapuchare in Nepal is of special significance to Hindus, and as such is off-limits to climbers (and indeed has never been summitted). It is not the only mountain steeped in myth in the Himalayas,  and as such, it would be a mistake to assume that the burgeoning tourist industry could operate freely on every mountain. Similarly, the recent decision to ban tourists from climbing Uluru in Australia may not make economic sense, but consideration of cultural associations clearly is more important.

Some of these cases may seem isolated. But every culture has its own unique relationship with land, which is to some degree (big or small) influenced by myth and legend. Applying the same development strategy in each setting is misguided – and to me it seems this is particularly true for the modern concept of treating the landscape as a commodity to be exploited for profit. Indigenous peoples (in Canada, for example) have treated the land they depend on in a highly sustainable fashion, informed by their cultural memory of fables and myth. We may not be able to return to such a state of living in the modern era, but if we want to build a more sustainable economy and change our current ‘business as usual’ model, it would be fitting to look to those cultures that have achieved a sustainable fashion of living – and particularly fitting to ask ourselves what about their cultural memory encouraged them to live that way.

Robert Emberson is a science writer, currently based in Victoria, Canada. He can be contacted via Twitter (@RobertEmberson) or via his website (www.robertemberson.com).

Heather Britton: Sinkhole Occurrence and Mitigation

Sinkholes are often overlooked geohazards which, although far less destructive in the short-term than earthquakes and landslides, can be catastrophic to life and severely impact the built environment. This post will explore how these features form and the strategies that have been adopted to predict their appearance. It will also consider how urbanisation in karstic areas is accelerating sinkhole formation and what can be done to mitigate these effects.

Sinkholes form most commonly in karstic terrain – topography shaped by the dissolution of soluble rocks such as limestone, gypsum and dolomite. This dissolution creates cavities beneath the ground surface, and the subsidence of the land into these cavities creates sinkholes. Karstic regions are generally associated with three varieties of sinkhole, displayed in the figures below.

  • Figure 1 – Rainfall and surface water percolate through joints in the limestone. Dissolved carbonate rock is carried away from the surface and a small depression gradually forms. On exposed carbonate surfaces, a depression may focus surface drainage, accelerating the dissolution process. Debris carried into the developing sinkhole may plug the outflow, ponding water and creating wetlands. (Source: USGS Water Science School)

    The first are dissolution sinkholes, which form when dissolution is concentrated in a particular area, often along pre-existing joints or fractures within the rock where groundwater flow preferentially occurs. This causes the land to sink in this area and the result is a sinkhole.

  • Cover-subsidence sinkholes are characterised by a thick overburden of granular sediment which gradually falls into an underlying cavity.
  • The final variety, cover-collapse sinkholes, are undoubtedly the most dangerous as they can develop over a period of hours. Cover-collapse sinkholes occur where cohesive material overlies a soluble bedrock. When dissolution occurs in the carbonate/evaporite the overlying cohesive substance will form an arch over the cavity, making it very vulnerable to collapse. In 2013 Jeff Bush disappeared into one such sinkhole as he slept in his home in Seffner, Florida, demonstrating just how catastrophic these geohazards can be.

 

Figure 2 – Cover-subsidence sinkholes, where a thick, overlying, sandy sediment layer fills an underlying cavity, usually produced through carbonate/evaporite dissolution. Source: USGS Water Science School

Figure 3 – Cover-collapse sinkhole formation. Due to the cohesive nature of clay and similar sediment, these sinkholes often do not form gradually and instead tend to appear very suddenly, creating the greatest risk to human life and property. This is usually as a result of an influx of water, causing the layers in the clay to slide over one another. Source: USGS Water Science School

Worryingly, the appearance of sinkholes seems to be on the increase. Urbanisation is accelerating the rate at which sinkholes form, as it is intrinsically linked with processes such as construction and mining. Groundwater pumping associated with construction work changes the natural drainage patterns of the land, leading to dissolution in regions where it has not been seen before. On top of this, increased agriculture to feed the growing population involves the drainage of organic soils, leading to the runoff of organic carbon and the production of highly acidic water sources (pH 3.4-4 recorded in some instances) which inevitably accelerates the dissolution of soluble bedrock. Groundwater pumping in particular was responsible for 80% of identified subsidences in the US where sinkholes are a problem across many states. And the issue is not limited to the US – karstic regions around the world are seeing an increase in the number of human induced sinkholes, for example those which effecting the Madrid-Barcelona High Speed railway. Human activities are undoubtedly impacting sinkhole formation, be it through mining, agriculture or construction.

Aerial view of a large collapse structure, the Tres Pueblos sink, along the Rio Camuy, which exits on the far side of the sinkhole. Solution of underlying rock removed the support and the roof of soil and thin bedrock collapsed into the void. This produces what is known as karst topography. (Courtesy United States Geological Survey)

So what is the best way of allowing development to occur without exacerbating the anthropogenic effect that urbanisation can have on sinkhole formation? One of the simplest and most frequently implemented solutions is to avoid building in regions that may develop sinkholes, or have been shown to be prone to sinkholes in the past. This planned development can be implemented on a small scale, but it is unrealistic to avoid the development of large karstic regions altogether. Carefully considering the drainage networks of new builds and infrastructural projects may help to minimise the effects of development on sinkhole evolution – but sometimes the development pressure is much greater than any impetus to properly consider the state of the land which is being built on.

Currently our best solution to urbanisation in karstic areas is to monitor sinkhole development and attempt to detect them as soon as they appear. Monitoring is possible through geomorphological mapping and the use of GIS and DEM (Digital Elevation Mapping), whilst detection can be achieved with relative ease using geophysical methods (e.g., seismic data and radar). Although not preventative, such techniques do allow sinkholes to be identified early in their development, therefore they can be either avoided or filled before any serious damage is attained.

Even knowing where developing sinkholes lie does not stop construction occurring over them. A short term solution to a developing sinkhole is to fill it, often with concrete, as was done in Zaragoza, Spain. Here the sunken region was waterproofed before being injected with concrete. Whilst it might be thought the initial waterproofing step would end the cycle of dissolution and sinkhole formation, this action was actually seen to increase karstic activity. Filling sinkholes with concrete is not a sustainable solution – it does not prevent sinkholes from continuing to subside (although it may prevent catastrophic collapse) and too much concrete would be required to fill all sinkholes which pose a threat to human property. Other materials are in greater abundance, however, for example rubbish. It is highly unlikely that we will grow short of this ‘resource’ and the planet is currently in need of more landfill sites. The primary risk of this technique is the contamination of groundwater and other water sources – even if rubbish was only used in regions where there was a low risk of water contamination, the danger that groundwater flow would change and begin to poison sources of drinking water would always exist, making this a risky strategy, particularly in regions undergoing heavy urban development or in tectonically active areas. Geologists are working towards solutions – This student paper looks into how sinkholes can be stabilised, removing the danger of collapse – but many sinkholes have unique features which set them apart from the rest, therefore one solution may not be appropriate in all instances.

As the number of sinkholes grows, it is becoming more and more important that we develop better ways of dealing with and preventing this geohazard. Currently our efforts are limited to planning around sinkholes and detecting and monitoring their evolution early, but with urbanisation spreading into karstic regions around the world further work must be done to reduce the risk that this hazard holds for communities. Research is ongoing, and hopefully in the near future will yield not only better detection and mitigation technologies, but more effective and sustainable methods of dealing with sinkholes once they form.

Guest Blog: Africa, Groundwater and the Sustainable Development Goals

Figure 1. Image of Dr Callist Tindimugaya from the Ministry of Water, Uganda. Dr Callist presented the 2017 Ineson lecture. He is a key figure in Africa achieving the sustainable development goals for 2017.

Africa faces a range of groundwater and development issues such as a lack of groundwater data, rising populations and urbanisation. On the 25th October Charlotte Copley attended the joint meeting of the International Association of Hydrogeologists (IAH) and the Hydrogeological Group of the Geological Society, which included the Ineson Lecture at the Geological Society of London.

With only two hydrogeology lectures on my back and a very limited knowledge of Africa, I found the experience of being at this meeting to be truly mesmerising and it has widened my thoughts on what we can do to help Africa be on its way to achieving the 17 UN Sustainable Development Goals. The day consisted of five lectures, each on a range of issues surrounding Africa and its water supply, a debate on the theme “Each time an NGO, charity or private company constructs a water well or borehole for community water supply, they should be required to pay a small levy to Government to cover the costs of the groundwater monitoring and governance activities undertaken by the relevant public sector organisations” and a panel discussion on the Sustainable Development Goals in Africa.

This blog focuses on the lecture I found to be the most informative as a whole on the current issues Africa faces. This lecture was given by Dan Lapworth from the British Geological Survey and was titled “Urban groundwater & groundwater quality in Africa”. The general message received from this lecture was that groundwater in Africa is a resource we cannot afford to overlook due to rapidly rising populations, urbanisation and changing behaviours in terms of water usage.

Some areas of Africa have the highest population growth globally!

The population in Africa is a growing, low income, urban population, where it is estimated that there will be 6,000 cities in West Africa by 2020, where Nigeria is a hotspot.

Africa has a huge freshwater resource that is quite shallow, making it fairly accessible. This poses a real potential for future development especially as there are moderate to high productivity aquifers in most places. Deeper and better sources that are more protected from these challenges are also currently underutilised.

The current national groundwater use in Africa is around 10-50%

Dan shared the main issues with the water supply in Africa. The points given below show how far behind Africa is in water treatment technology, highlighting the lack of people being trained in this field and how little advancement in this industry has occurred in Africa. The key water quality challenges that Africa faces are vast; some of these include:

  • Faecal waste management contamination of shallow water systems
  • Geogenic contaminations (i.e. Arsenic and Fluoride)
  • Hydrocarbons and organic contaminants are present in urban areas
  • Legacy contaminations from industry
  • There is limited treatment, even for municipal sources

The key water supply and health challenges that Africa faces include:

  • Water access in low income areas is wholly inaccurate
  • Piped or kiosk water is not affordable, alternative high risk sources are used
  • There is a higher risk from faecal contamination during flooding/shallow groundwater conditions
  • Augmented self-supply is common for both high and low income groups

The current trend in Africa is that the majority of households own their own borehole, with 51% of households in Nigeria owning their own borehole, 36% of households share a borehole and only 33% accessing a public water supply.

It was clear to see from this lecture that Africa is behind with water supply and quality; major changes and advancements need to be made for the UN Sustainable Development Goals to be achieved by 2030. With groundwater demands set to increase in future, this problem needs to be addressed and action needs to be taken.

For this to happen Africa needs to prepare for a groundwater revolution. This needs to begin with the government introducing education schemes, teaching future generations the importance of having a good and continuous supply of water and how this affects health and gender equality. Local water supplies in villages also needs to be improved, by maintaining and monitoring the wells that have been put in place by outside organisations. More data points are needed on aquifer location, characteristics, ground water quality and how the groundwater levels fluctuate in response to seasonal and inter-annual recharge, along with long term pumping. Further to this, more resources of water in Africa need to be utilised, especially deep water resources that are less prone to contamination.

Through projects such as UPGro and GroFutures, this can be achieved. Given time, awareness can be raised in communities of the importance on the future pathway of Africa’s water supply!

Take home message: Water is key to improving the lives of Africa’s ever growing population. It is currently seen as the women’s job to collect water, however, with the instalment of taps in villages, providing a clean, reliable water supply, women can have the opportunity to be educated, which will improve gender equality. If the role of water is introduced into education, people will learn about the issues regarding unsanitary supplies, health will improve as people become more informed. Water is the key for life and no human can survive without it, it needs to stop being a neglected subject and be at the forefront of the development in Africa.

Written by: Charlotte Copley, Third Year Undergraduate Geology Student, University of Liverpool