Landslides and floods triggered by earthquakes pose a great threat to human life and infrastructure. Currently, research into mitigation of these natural hazards has focused on events triggered during or shortly after earthquakes; for example, the failure of a slope shortly after a seismic event.

However, the long-term seismic effects that cause unstable landslides to accelerate without immediate failure are largely neglected. A new project, ‘Advancing knowledge of multi-hazards processes and their impact’ (AMHEI), aims to fill this research gap by looking at slope dynamics following a major earthquake and how these processes can also affect flood hazards.

There is currently little research into earthquakes affecting landslides and flooding in the longer term. We are excited to be able to utilise latest satellite technologies to better understand the relationships between these hazards.

Alessandro Novellino, BGS Remote Sensing Geoscientist.

AMHEI will use the latest satellite technologies, includingÌýInterferometric Synthetic Aperture RadarÌý(InSAR) combined with artificial intelligence techniques, to map and identify relationships between natural hazards in Turkey, using the February 2023 earthquake as a case study.

Funded by the European Space Agency, the project will be led by Alessandro Novellino, a remote sensing geoscientist at BGS, in collaboration with colleagues at the Faculty of Geo-Information Science and Earth Observation at the University of Twente (Netherlands) and the University of Bergen (Norway).

Research led by a BGS scientist has revealed that an estimated 1.9 to 2.7 million people in the Bandung metropolitan region of Indonesia would be exposed to high levels of ground shaking from an earthquake on the nearby Lembang Fault.

Over the past five years, Ekbal Hussain, a remote sensing geoscientist at BGS, has worked alongside scientists in Indonesia to research and produce deformation maps for the Bandung metropolitan region. To do this, they used a combination of data from satellites and GPS measurements made around the fault.

Bandung is the capital of West Java, Indonesia, and has a population of approximately 8.4 million people. The centre of the city lies less than 10 km south of the Lembang Fault, a major fracture between two blocks of rock in West Java. Although there are no documented records of large historical earthquakes, the Lembang Fault shows geomorphological evidence of significant earthquakes in the 15th century.

A fault slip rate is the average amount of earthquake energy accumulation each year; using different techniques, this had previously been estimated to either be between 1.95 to 3.45 mm a year or 6 mm a year for the Lembang Fault. This new study has found that the slip rate is 4.7 mm a year.

Using this new slip rate alongside previous studies, which estimated the recurrence period of large earthquakes on the fault at between 170 and 670 years, it can be estimated that the magnitude of an earthquake will be between 6.6 and 7.0. If such earthquakes were to occur on the fault today they would expose approximately 1.9 million to 2.7 million people within the Bandung metropolitan region to high levels of ground shaking, greater than 0.3 g, or 30 per cent of the strength of gravity.

The research highlights the importance of not forgetting local crustal faults located near large urban centres, which also pose a high risk to communities.

In Indonesia, the perceived risk of earthquakes is from large events on the subduction zone. However, in this paper, we show that shorter faults like the Lembang Fault, located much closer to major cities, can also be extremely dangerous.

Ekbal Hussain, BGS Remote Sensing Geoscientist.

Funding

This is work is funded by the UK National Capability ‘Geoscience to tackle global environmental challenges’ programme. The BGS and Indonesian researchers involved in this study are continuing their engagement with local government to address the hazard challenges raised in this work.

More information

Access the full paper:

My name is Maureene Auma Ondayo and I am a 51ÁÔÆæ-funded PhD candidate at the University of Eldoret, Kenya, and BGS, with a background in environmental and public health. In this blog I will share my PhD research, investigating major and trace element exposure in the environment. This includes ores, soils, sediment and waters, locally grown staple food crops (maize, leafy vegetables, pulses and tubers), and human samples (hair, nails and urine). My research also incorporates risk factors of exposure to potentially harmful elements (PHEs) and associated health implications among artisanal and small-scale gold mining workers and local residents.  

What is artisanal and small-scale gold mining?  

Artisanal and small-scale gold mining (ASGM) is an informal mining sector that provides subsistence-level livelihoods for many rural communities across the world. In Kenya, ASGM occurs in Migori, Narok, Siaya, Vihiga, Kakamega, Nandi, Kisumu, Turkana, West Pokot, Marsabit, Homa Bay and Kericho counties. It is estimated that ASGM production yields around 5 metric tons per year (worth around £250 million), employing 250 000 workers with more than 1 million dependents. The main environmental and health risks associated with ASGM relate to poor conditions at mining camps and mining operations, which include the extensive misuse of mercury in the production process.   

Mining the gold 

Miners often rely on local knowledge when prospecting for gold after which agricultural land and pristine forests are cleared to make way for the mine. Ores are excavated and broken into smaller pieces using sledgehammers and mills, dispersing large volumes of contaminated dust across nearby environments and communities. Milled ore powder is then wetted and sluiced to extract the gold particles. Panning separates gold-associated sediment particles, then liquid mercury is added, which joins together with the gold to form an amalgam and separates it from the sediment. The amalgam is then burnt on open flames, vaporising the mercury and leaving behind the gold, whilst tailings and wastewater from ASGM are disposed of in nearby farms, residences, playgrounds and waterways. 

These activities expose the workers and local populations to extreme health and safety hazards, with injuries, diseases and premature deaths reported in ASGM areas.  

Hazards of ASGM 

Exposure to potentially toxic elements (PTEs), physical hazards, gaseous emissions, overexertion, physical injuries and poor ventilation inside the mines are the key hazards to human health in ASGM. This exposure results in a wide range of health disorders including:  

• cancers 
• immunity suppression 
• neurological disorders 
• developmental health effects  

Socio-economic issues related to mining activities are also present in local areas, including alcohol and addiction, violence and HIV/AIDs.  

My research 

During my PhD, I investigated the environmental and human exposure and health implications among nineteen ASGM communities in Kakamega and Vihiga counties, Kenya. 

I collected soil, sediment, water, locally grown food and human biomarker samples (hair, nails and urine) from ASGM workers and residents of ASGM villages and analysed them for major and trace elements at BGS Inorganic Geochemistry Facility in Keyworth. Further risk factors from PTE exposure and potential health effects among the studied ASGM communities were assessed through interviews.  

Study results 

Kakamega and Vihiga counties are naturally enriched with macro- and micro-elements and the ASGM activities primarily disperse them across surrounding environments and communities. The results show that:  

• soils, sediments and water sources in the ASGM villages were highly polluted by PTEs, including arsenic, mercury, chromium, lead and nickel 
• soil concentrations of arsenic, chromium and nickel in the studied ASGM villages were 154, 9 and 4 times higher than background concentrations, respectively 
• drinking-water samples in the ASGM villages, including springs, shallow wells and mine shafts, were heavily polluted with arsenic, lead and chromium. Very worryingly, we observed mine workers and residents drinking mine-shaft water, the most contaminated water at the ASGMs, when they were extracting the ore!  
• locally grown staple food crops were also contaminated with arsenic, nickel, lead, chromium, cadmium, mercury and aluminium, and were not considered safe for consumption  

The inhalation of gaseous PHEs like mercury during amalgam burning, the consumption of locally grown staple food crops and drinking water, and ingesting PTE-contaminated dust and soils (especially children and pregnant women that exhibit pica, that is, eating non-food items like soil) were the main exposure pathways found in our study. Self-reported potential pollution-related health effects included cancers, neurological effects, respiratory infections, musculoskeletal effects, infectious diseases including HIV/AIDS, and malaria.    

Working with the ASGM community 

A key aspect of my PhD was the multidisciplinary research approach taken to understand the relationships between the environment, diet and public health to effectively assess and communicate human exposure and health risks. We continue to collaborate with ASGM workers, local communities and local health practitioners while sharing our findings.  

On 2 December 2023, we met with county public health administrators to understand how best to present and share the data for interpretation with our key stakeholders. These include: 

• politicians 
• broader county employees 
• the departments of mining, environment, and law enforcement 
• community health workers 
•  the studied ASGM communities in both Kakamega and Vihiga counties 

Additional meetings with public health officers, medical practitioners, environment and agricultural departments and other key stakeholders are planned. This will let us share our results and recommendations on reducing PTE exposure through environmental, occupational and public health safety controls, such as: 

• providing safer drinking water to ASGM communities 
• relocating residences and schools away from ASGM activities  
• controlling dust transfer 
• encouraging regular personal protective equipment (PPE) use 
• alternatives to mercury 
• safer cyanidation operations 
• wet milling 
• technological interventions in ore exploration, excavation, processing and recovery 
• targeted education and training on industrial hygiene 
• public health policy formulation in ASGM in Kenya 

This study characterised PHE exposure pathways and health risks among ASGM communities in the Kakamega gold belt. Our findings are valuable to public health authorities as they inform them of the mitigation actions that are needed to research further, reduce exposure, improve ASGM processes, and protect the environment, food sources and the health of ASGM workers and residents, including policy formulation. 

About the author 

Maureene Auma Ondayo is a 51ÁÔÆæ-funded PhD candidate at the University of Eldoret, Kenya, and BGS, with a background in environmental and public health. 

Co-authors  

Prof Odipo Osano is an environmental toxicologist at the University of Eldoret, Kenya. He has a background in veterinary medicine, public health, and community and laboratory-based environmental epidemiological research.   

Clive Mitchell, BGS Industrial Minerals Geologist.   

Dr Olivier Humphrey, BGS Environmental Chemist.   

Dr Michael Watts, BGS Head of Inorganic Geochemistry and lead for BGS International Geoscience Research and Development.   

What springs to mind when you think about sand? More than likely you’ll picture yourself on a beach building sandcastles and leaving footprints in the sand on the way to the sea.

Sand isn’t currently featured in the news like critical and battery minerals, which are so important for creating our cars and electronics. However, it is one of the most important industrial raw materials on the planet and is the second most utilised resource on Earth, after water. This is due to its use in the dominant construction material of the modern world, concrete.

How do we extract sand?

Sand is a high-bulk, low-value commodity and is usually mined close to where it is needed. In the UK, it generally does not travel far — around 30 to 40 km by road on average. Not all sand is suitable for construction: it must meet specific technical requirements for size, shape and composition of the sand grains. For example, although there is a lot of sand in deserts, it is generally not suitable for construction.

The ever-increasing global population and mass migration to cities has led to rapid, ongoing urban growth, particularly in the developing world. This in turn has accelerated the demand for concrete and construction raw materials such as sand, as people standard of living and need for decent housing and infrastructure increase. In many parts of the world, this demand has led to extensive, unregulated and illegal sand mining in delicate and environmentally sensitive environments, such as rivers and beaches. This unregulated mining can cause problems such as:

• erosion
• damage to infrastructure
• increased flood risk
• habitat loss
• pollution
• soil degradation
• destruction of farmland

The unsustainable demand can also affect economic growth due to material shortages, demand spikes, rapid price fluctuations and delays to major construction projects.

As sand mining is often small-scale, informal and localised, there is little information on where sand is mined, how much is produced or where it is consumed. This lack of understanding and data is a significant global problem highlighted by the United Nations Environment Programme (UNEP).

Are we running out of sand?

The answer is not straightforward. We live on a big planet that is full of sand. We are not going to run out of it, but sand does not always occur in the places where it is needed. The goal is to find sand resources on a local level that can be extracted sustainably, with the minimum environmental impact, whilst still meeting local economic needs. This way we can continue to build with sand and protect the environment for future generations.

How is BGS involved?

51ÁÔÆæ has plenty of experience in monitoring, planning and managing sand resources in the UK. We work on geoscience-led solutions such as mapping resources and mines, understanding what makes a ‘good’ sand and looking into alternatives.

Keen to see how BGS could help in developing geoscience practices to solve the problems caused by the mismanagement of sand resources, a BGS team (Tom Bide, Alessandro Novellino and Clive Mitchell) recently visited Malaysia to meet with scientists, activists and the local industry as part of the BGS International Geoscience Research and Development (IGRD) programme.

We embarked on a non-stop tour of visits and meetings hosted by JMG (the Malaysian geological survey) and the helpful local representatives of the UK Science Innovation Network, hosted by the British High Commission in Kuala Lumpur. By talking to local quarrying companies, trade bodies, non-governmental organisations such as Friends of the Earth and academics from universities around Kuala Lumpur, we were able to really understand local issues. We saw examples of good practices to help us understand what does and doesn’t work on the ground in terms of resource management.

After two weeks in Malaysia dodging torrential downpours, being wowed by glittering skyscrapers and overindulging in the local cuisine, we attempted to create a few easily accessible resources using the good practice ideas we had learnt. We could then use them to promote better resource management in a range of countries where unsustainable sand mining is an issue.

In our next blog, we’ll discuss our findings and more information on the sustainable use of sand, as well as our new sand resources.

About the authors

51ÁÔÆæ is collaborating with the University of Zimbabwe (UZ) in a study to assess access to clean drinking water sources across the city of Harare and the impact of recent donor-led upgrades to groundwater supply systems.

A fragile municipal water supply

Harare is Zimbabwe capital, with a population of approximately 1.5Ìýmillion in urban Harare and another 1.1Ìýmillion living in the satellite towns of Chitungwiza, Norton, Epworth and Ruwa ().Ìý

The city main drinking water source, Lake Chivero, its tributaries are heavily polluted by industrial waste and raw sewage inflows and the city drinking water treatment works are insufficient to supply Harare water demand.

Daina Mudimbu, geoscientist at ZIVA Data & Knowledge Management Consultants.

The water system was designed in the 1960s and produces approximately 704 megalitres (ML) of water per day against an estimated demand of between 800 ML to 1300 ML of daily water consumption (ZimFact, 2021).

Frequent outbreaks of waterborne disease

The response of the city water department has been to ration water, leading to an erratic piped water supply to communities that has been associated with a rise in outbreaks of waterborne diseases. In 2008 and 2009, Zimbabwe experienced one of the worst cholera outbreaks, resulting in the many deaths of mostly urban dwellers.

A city dependent on groundwater sources

The aged and inadequate infrastructure for water and waste-water treatment, increased drought and poor revenue collection from water surcharges on households have hampered the municipal water supply system, leading to greater dependence on groundwater.

Recurrent droughts of the 1980s and 1990s ushered in rampant drilling of private boreholes. This has culminated in the drying up of some shallow wells across the city, due to over-pumping.

Moses Souta, technician at the Department of Construction and Civil Engineering, University of Zimbabwe.

The failure of municipal infrastructure to meet the growing potable water demand has given rise to dependence on groundwater, with reports of 80 per cent of Harare population relying on groundwater supply (). 

During a trip to Harare in January 2023, BGS Bentje Brauns was able to visit a number of community drinking water sources.

You can see the impact of recent donor programmes to try and improve access to water in high-density settlements through developing groundwater resources. This has included upgrading boreholes and the installation of a large number of solar pumps, water tanks and in situ chlorination systems.

Bentje Brauns, BGS Hydrogeologist.

The challenge of finding drinking water

Though the city geology is variable, it is mostly ‘hard rock’ basement geology, therefore      groundwater occurrence is controlled by the presence of fractures. As a result, in some suburbs where there are few fractures, drilling may be unsuccessful or boreholes may only work for part of the year because of limited recharge through the fracture network. Poor sanitation and waste management as well as increasing urban pollution have compounded the challenge and have led to groundwater contamination. Some boreholes have been condemned as seasonal cholera and typhoid outbreaks affect communities.

Have recent donor upgrades to community supplies been effective?

A host of donors have worked in recent years to improve and upgrade groundwater drinking sources in high-density settlements across the city in response to this worsening water crisis. Recent communal borehole development projects include the establishment of community water point committees. These committees mobilise local resources, including household monetary contributions, to maintain the water point and continue with chlorination initiated by the donors when the borehole was completed. However, continued chlorination has been reported to be a challenge at many water points because the communities fail to raise the required funding, or the water point committees fail to thrive.

The question remains: have these upgraded sources been effective in providing improved drinking water quality and can they be sustainable, at least in the medium term?

Dan Lapworth, BGS Principal Hydrogeochemist.

We are trying to answer these questions through our collaboration to inform future policy on groundwater development in Harare and elsewhere in this region.

Samson Shumba, engineer and chairman of the Department of Construction and Civil Engineering, University of Zimbabwe.

Assessing groundwater quality in recently improved and historical sources

Monitoring groundwater resources and quality is critical to ensuring the sustainability and safety of water supplies. While big steps have been made recently in implementing monitoring systems, gaps in our understanding certainly remain and opportunities exist for closer monitoring of the water quality and quantity.

Funding

This work is being undertaken as part of the International Geoscience Research and Development (IGRD) project ‘Geoscience to tackle global environmental challenges’ (NERC reference NE/X006255/1). This is a £12 million project lasting until 2026, looking at challenges facing communities around the globe, including clean water availability, earth hazards and climate change impacts.

About the authors

, geoscientist at ZIVA Data & Knowledge Management Consultants

, consultant hydrogeologist at the Africa Groundwater Network

, engineer and chairman of the Department of Construction and Civil Engineering, University of Zimbabwe

, technician at the Department of Construction and Civil Engineering, University of Zimbabwe

Researchers from BGS and partners in Zimbabwe report on the urban water supply challenge in the capital city, Harare.

The white sands of Boracay were now 300 km behind us as we touched down in Manila to meet BGS Majdi Mansour, Susanne Sargeant and Nicole Archer (along with her five bags and 60 kg of luggage, for an art exhibition later in the week). The BGS team was now five strong, which was useful as we were going to be busy over the next 10 days.

Monday started at 02:30 and everyone had the same bleary-eyed look that was becoming a common theme on this trip. A long journey was on the cards and the packed breakfast provided by the hotel left a lot to be desired. The team were beginning to question why they’d signed up to this sleep-deprived trip, when spirits were lifted by the Ateneo de Manila University (ADMU) team joining us.

We reached Bacolod in time to catch our second breakfast of the day, eaten with our host family in a traditional Filipino home. For those who were there, this breakfast was perhaps the pinnacle of all other breakfasts in our lives! Our next stop was a primary school in Isabela where we were running a groundwater education event with 500 students. Sleep deprivation, language barriers and being put in charge of half a thousand students, what could possibly go wrong?

Very little, as it turned out. Andy M got started with a talk about groundwater and the hydrological cycle with a translator who would have been at home warming up a gig crowd of 20 000. Following this everyone broke into six groups, running a range of experiments with buckets, sand, pumps and food dye, with teachers translating to the children. The team had lunch with the school principal, where letters were handed over from Radcliffe-on-Trent Junior School (UK), who want to form a new international partnership. Finally, it was time to head back to Manila and the following five hours were a blur of heavy rain, mangos, noodles and soft snoring.

Back in Metro Manila: art, networks and workshops

Tuesday started with breakfast, blue sky and bright sunshine. Had the visit to Bacolod been some sort of collective dream? The blue and red food dye on our fingers told us otherwise. Nicole had already left to continue setting up her art exhibition (due to open that evening) and the rest of the team headed to the ADMU campus, where Majdi was delivering the first part of the MODFLOW model training. With visits to the British Embassy and British Council the following day, Susanne and Andy M were busy preparing presentations.

The training session ended at 17:00 and we headed across campus to meet Nicole, not knowing what to expect. Wow, it was hard to comprehend that those bags at the airport had contained so much amazing and evocative artwork! We didn’t manage to catch up with Nicole until later that evening as she was too busy liaising with city mayors and government officials. A couple of hours later, Nicole managed to relax after her busy event and over dinner let slip that one of the abstract art pieces was hung upside down. Don’t worry Nicole, .

Nicole’s perspective

I had 10 members of staff assigned to help me set up the exhibition. There was a lot to do and very little time to create an exhibition within an empty black box, the Doreen Theatre, in the . Luckily, the theatre team worked like a well-oiled machine under the direction of D Cortezano. 

D had the perfect booming voice of a theatre artist and it was put to good use in directing his team to work in unison within the high-tech 3D space of the Doreen Theatre. Back in the UK, the exhibition was just a concept  within the pages of a PDF document, but now the exhibition ‘Living with Water’, created from collaborative work of Ateneo de Manila University, the University of Vietnam, BGS and Queen Margaret University (UK), was to become reality. All this was made possible through funding from the ADMU Hub of Creativity and Innovation and a grant obtained by Aleen Guzman, our lead Filipino partner.

Back in the Doreen Theatre, curtains were rearranged and hung from the ceiling catwalk to divide the room into three spaces. Space 1 contained six large textile artworks suspended from the ceiling and ten underwater film stills, introducing three rivers from the Philippines, Vietnam and the UK. Space 2 showed eight 2 m-high textile images that were hung from the ceiling and catwalk frames, with spotlights positioned to shine through each image. Within this space, audio played the voices of people narrating their experience of being flooded by the rivers that had been introduced in Space 1. Space 3 was laid out as a participatory area to enable visitors to think about the relationship between people and rivers, and question how we need to change this relationship if we are to become more resilient to flooding in the future. The final touch was adding the information boards containing QR codes so that viewers could read extra information from the .

By 16:45 we were ready for the opening and it was time for that long-waited lunch.

Later, the upside-down artwork was adjusted (thanks Andy for that!). Fortunately, it was not a famous Mondrian painting! Over four days, 300 people came to the exhibition and two creative workshops with ADMU environmental science students took place within Space 3. Overall, the exhibition had extremely positive feedback and we will be continuing to foster more creative collaboration between ADMU and BGS.

The hydrological modelling project is a partnership between BGS and governmental and academic institutions in the Philippines. It aims to improve the understanding of national water resources and identify the impact of future climate change and development on these resources.

After flying through multiple time zones and with far less than the recommended eight hours of sleep, we arrived bleary-eyed at Manila airport in the Philippines to meet our hosts from Ateneo de Manila University (ADMU). Our destination for the next few days was Boracay, billed as one of the most popular tourist hotspots in the Philippines. Thoughts of beaches, hammocks and mango ice cream filled our minds as we landed at Caticlan airport and were met by a live band at arrivals.  

New Nabaoy river gauging station

We grabbed our suitcases and headed to our first stop, the Nabaoy river catchment Panay, to view a new river gauging station installed by ADMU and partners at the National Water Resources Board (NWRB). River gauging stations look at the flow and depth of the river, as well as some pollutants. There was a lot to discuss around groundwater residence times (the time water stays in the ground) and further development of sensors. With a light drizzle reminiscent of the UK we headed back into the bus to catch a boat to Boracay and, with the light fading, we made it to the hotel. The beaches would have to wait for tomorrow. 

Rising early, the skies were blue and the breeze was warm and gentle. We met the ADMU and NWRB teams at breakfast to discuss the day work. Two hours later, we were back at the Nabaoy river, talking to the local mayor and various government departments about hydrogeology, modelling and climate before taking part in a ribbon-cutting ceremony. The river gauging station was officially open!

We spent the remainder of the afternoon with the mayor and ran a series of groundwater experiments with local children, teaching them about water resources, pollution and hydrogeology. Once again, those world-famous beaches would have to wait… 

Learning about Boracay

Wednesday began in a similar way to Tuesday, with a large breakfast and a discussion about the plan for the day. We boarded a bus and headed south, passing through the corridor of shops, cafes, homes and hotels that line Boracay western coastline. Again, we were greeted by local and regional government officials for a second ribbon-cutting ceremony at a new groundwater observation well. This time, Andy M was asked to wield the scissors.

An hour later, we were back at the hotel for a conference about the sustainability of water resources on the island. We learnt about the hydrology and ecology of Boracay and the Nabaoy watersheds, including some endemic, foot-long stick insects, and Andy B presented forecasts on the future of regional climate and hydrology up to the end of the century. This generated discussion around potential impacts on water resources and disaster recovery.  

The next day we said our farewells to our project partners and headed to the beach for mango ice cream and to reflect on the last few days. The white sands and turquoise waters were the perfect way to unwind before ten days of delivering workshops, school sessions and training in Manila!

Vulnerability of small islands

The Intergovernmental Panel on Climate Change (IPCC) has identified small islands as high-risk settings facing adverse climate change impacts. They have limited, vulnerable resources and few freshwater sources. Small islands also have a high dependency on tourism in terms of exports and contribution to gross domestic product (GDP), however, tourism needs to be well managed to avoid deterioration of local water supplies.

Small islands present three key characteristics that make them particularly vulnerable to social, economic and environmental impacts:

• small size, which adds pressure on water resources and limits economic diversity
• isolation, which brings trading challenges, unique biodiversity and cultural richness
• maritime environment, leading to vulnerability to climate change

Understanding how climate change and differing tourism approaches impact hydrology provides a pathway to improved water security. Understanding and assessing impacts will require a unique approach integrating geosciences, social science and economics.

Funding

This fieldwork was undertaken as part of the International Geoscience Research and Development (IGRD) project ‘Geoscience to tackle global environmental challenges’. This is a £12 million project lasting until 2026, looking at challenges facing communities around the globe, including clean water availability, earth hazards and climate change impacts.

About the authors