Geology for Global Development

Sustainable Development Goals

Saltwater intrusion: causes, impacts and mitigation

In many countries, access to clean and safe to drink water is often taken for granted: the simple act of turning a tap gives us access to a precious resource. In today’s post,Bárbara Zambelli Azevedo, discusses how over population of coastal areas and a changing climate is putting ready access to freshwater supplies under threat. 

Water is always moving downwards, finding its way until it gets to the sea. The same happens with groundwater. In coastal areas, where fresh groundwater from inland meets saline groundwater an interesting dynamic occurs. As salt water is slightly denser than freshwater, it intrudes into aquifers, forming a saline wedge below the freshwater. This boundary is not fixed, it shows seasonal variations and daily tidal fluctuations. It means that this interface of mixed salinity can shift inland during dry periods, when the freshwater supply decreases, or seaward during wetter months, when the contrary happens.

Freshwater and saltwater interaction. Credit: The National Environmental Education and Training Foundation (NEEF).

Once saline groundwater is found where fresh groundwater was previously, a process known as saltwater intrusion or saline intrusion happens. Even though it is a natural process, it can be influenced by human activities. Moreover, it can become an issue if saltwater gets far enough inland that it reaches freshwater resources, such as wells.

According to the UN report, about 40% of world’s population live within 100km from the coastline or in deltaic areas. A common source of drinking water for those coastal communities is pumped groundwater. If the demand for water is higher than its supply, as can often occur in densely populated coastal areas, the water pumped will have an increased salt content. As a result of overpumping, the groundwater source gets contaminated with too much saltwater, being improper for human consumption.

With climate change, according to the IPCC Assesment Reports, we can expect  sea-level to rise, more frequent extreme weather events, coastal erosion, changing precipitation patterns and warmer temperatures. All of these factors combined with the a increased demand for freshwater, as a result of global population growth, could boost the risk of saltwater intrusion.

Shanghai – an example of densely-populated coastal city. By Urashimataro (Own work) [CC BY-SA 3.0 ],via Wikimedia Commons.

Although small quantities of salt are important for regulating the fluid balance of the human body, WHO advises that consuming higher quantities of salt than recommended can be associated with adverse health effects, such as hypertension and stroke. In this manner, reducing salt consumption can have a positive effect in public health, helping to achieve SDG 3.

With the aim of preserving fresh groundwater resources for coastal communities at present and in the future, dealing with the threat of saline intrusion is becoming more and more important.

Therefore, to be able to mitigate the problem, first of all, it needs to be better understood. This can be done by characterising, modelling and monitoring aquifers, assessing the impact and then drawing solutions. Currently there are many mitigation strategies being designed worldwide. In Canada, for example, the adaptation options rely on monitoring and assessment, regulation and engineering. In the UK, on the other hand, the simpler solution adopted is reducing or rearranging the patterns of groundwater abstraction according to the season. In Lebanon, a fresh-keeper well was developed as an efficient, feasible, profitable and economically attractive way to provide localised solution for salination.

Every case should be analysed according to its own characteristics and key management strategies adopted to ensure that everyone has access to clean and safe water until 2030 – SDG6.

How do you monitor an internationally disruptive volcanic eruption? How can you communicate SDGs in an Earth Science class? Jesse Zondervan’s Nov 13 – Dec 13 2017 #GfGDpicks #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 four weeks:

Bali’s Mount Angung started erupting ash this month, and a post on the Pacific Disaster Center’s website gives you an insight into the workings of Indonesia’s early warning and decision support system. How do you monitor an internationally disruptive volcanic eruption?

In Japan, eruptions in 2016 were preceded by large earthquakes (MW 7.0). A team of researchers used Japan’s high resolution seismic network to investigate the underground effects of earthquakes and volcanoes. How does an earthquake affect a volcano’s activity?

Next to plenty of disaster risk stories – including the simple question: why can’t we predict earthquakes? -, this month brings you a computer simulation tool to predict flood hazards on coral-reef-lined coasts and some thoughts on how to communicate SDGs in an earth science classroom.

Have a look!

Education/communication

The UN Sustainable Development Goals – what they are, why they exist by Laura Guertin at AGU’s GeoEd Trek blog

GeoTalk: How an EGU Public Engagement Grant contributed to video lessons on earthquake education by Laura Roberts-Artla at the EGU’s GeoTalk blog

Credit: Michael W. Ishak, used under CC BY-SA 4.0 license

Disaster Risk

Disaster Geology: 2017’s Most Deadly Earthquake by Dana Hunter at Scientific American

Can the rubble of history help shape today’s resilient cities? By David Sislen at Sustainable Cities

The underground effects of earthquakes and volcanoes at phys.org

Why Can’t We Predict Earthquakes? By David Bressan at Forbes

Detecting landslide precursors from space by Dave Petley at the AGU Landslide Blog

Ocean Sediments Off Pacific Coast May Feed Tsunami Danger by Kevin Krajick at State of the Planet

Life-saving technology provides alert as Bali’s Mount Agung spews ash, raises alarm at Pacific Disaster Center

Climate Change Adaptation

Scientists counter threat of flooding on coral reef coasts by Olivia Trani at AGU’s GeoSpace blog

Check back next month for more picks!

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

New Paper: Geoscience Engagement in Global Development Frameworks

We have recently contributed to a new open access article included in a special volume coordinated by the International Association for Promoting Geoethics (IAPG)This article, synthesises the role of geoscientists in the delivery of the UN Sustainable Development Goals, the Sendai Framework for Disaster Risk Reduction, and the Paris Climate Change Agreement, and discusses ways in which we can increase our engagement in the promotion, implementation and monitoring of these key global frameworks.

Abstract: During 2015, the international community agreed three socio-environmental global development frameworks, the: (i) Sustainable Development Goals; (ii) Sendai Framework for Disaster Risk Reduction, and (iii) Paris Agreement on Climate Change. Each corresponds to important interactions between environmental processes and society. Here we synthesise the role of geoscientists in the delivery of each framework, and explore the meaning of and justification for increased geoscience engagement (active participation). We first demonstrate that geoscience is fundamental to successfully achieving the objectives of each framework. We characterise four types of geoscience engagement (framework design, promotion, implementation, and monitoring and evaluation), with examples within the scope of the geoscience community. In the context of this characterisation, we discuss: (i) our ethical responsibility to engage with these frameworks, noting the emphasis on societal cooperation within the Cape Town Statement on Geoethics; and (ii) the need for increased and higher quality engagement, including an improved understanding of the science-policy-practice interface. Facilitating increased engagement is necessary if we are to maximise geoscience’s positive impact on global development.

PDF (open access) here: http://www.annalsofgeophysics.eu/index.php/annals/article/view/7460/ 

Introducing Our New Authors (2) – Heather Britton

Exploring Zhangjiajie National Park, Hunan province, China

We’ve been introducing you to a couple of new faces on the GfGD blog, bringing fresh ideas and perspectives on topics relating to geoscience and sustainable development. We’re delighted to have their input, and look forward to their posts. Today we interview Heather Britton – a recent graduate of the University of Cambridge (UK). 

Tell us a bit about yourself.

I’ve recently graduated with a Master’s in Earth Sciences and have just returned from a summer of travelling around China. Like many graduating geoscientists, I’d like to do work that has a positive impact on the world and GfGD has helped to show me how I might be able to do that. I am looking forward to getting more involved with the charity through these blog posts and hope not only to enlighten others, but to learn myself about the interface between geoscience and international development.

I love spending time outdoors – I enjoy hiking and play rugby regularly. I also travel as much as I can; I have been accused by family of only studying Earth Sciences for the travel opportunities it brings, but in truth this is just one of the many perks of studying this versatile subject.

How did you become involved with GfGD?

I attended the Geology for Global Development annual conference last year, and was really inspired by the talks, poster session and discussions held there. If anyone is hesitant as to whether or they not they should attend, I highly recommend it [editor: details of 2017 event can be found here!]. The conference demonstrated to me that it was not only possible to have an ethical career using my degree in Earth Sciences but that it is crucial for the geosciences to be considered when undertaking development projects. From there I took a greater interest in international development and the involvement that the geosciences could have. I wanted to get more involved in the work of GfGD, so when I saw their call for volunteers I was quick to sign up and here I am.

What did you do in your Master’s?

In my final year I specialised in climate science, palaeontology and some petrology, although I find the whole spectrum of Earth Sciences interesting and you can expect my posts to cover a wide range of geoscience fields.

My research project was palaeontology based and I confess not particularly development related! The aim of the project was to calculate the lifespan of ammonites from the growth lines on their aptychi (calcitic plates thought to either be the lower jaw structure or opercula of certain species of ammonite). On top of this I looked into the palaeobiology and palaeoecology of ammonites, using oxygen isotopes to estimate the temperature of the water in which these organisms once lived. I enjoyed the research and am considering doing a PhD in the future.

What can we expect your blogs to cover?

I hope to cover a wide range of topics so that I can appeal to the interests of as many people as possible. I am also looking forward to summarising papers covering the geosciences and international development and connecting these with the UN Sustainable Development goals which underpin so much of the work that GfGD does.

An example of an issue I have been reading about recently is sustainable coral reef management and how developing communities can benefit from the sustainable use of the resources that these environments have to offer, for example through tourism. Regional co-operations are popping up in highly affected areas working to protect reef environments but there is still a lot of work to be done to preserve these unique and hugely biodiverse environments and make local people aware of what does and does not damage these sensitive ecosystems. I also have an interest in how best to make vulnerable communities more resilient to disasters, be they earthquakes, tsunamis or hurricanes like those that have been in the headlines these past few weeks.

Plans for the future?

My dream job would be using my knowledge of geoscience in an ethical way to make a positive difference to the world, whilst involving a lot of travel. For now, however, I am more than happy to invest time in writing blogs for this fantastic charity – it is certainly a step in the right direction.

**This article expresses the personal opinions of the author (Heather Britton). These opinions may not reflect an official policy position of Geology for Global Development. **