Forecasts for the 2026 South Asia monsoon are for below average rainfall, but some of the most landslide prone areas of India may receive totals that are above average.

As usual, we are now starting to see the number of reported global fatal landslides increase as the northern hemisphere rainy season commences. In recent days, there have been fatal floods and landslides across several provinces of mainland China as well as landslides on the pilgrimage route to Kederath in northern India.

The global pattern is dominated by the South Asia (southwest / summer) monsoon, so it is interesting at this point to to consider the prospects for this year. The monsoon itself is expected to start in SW India next week, timing that is normal. It will then build over the following month or so.

The current forecast for the monsoon itself is that the total rainfall is likely to be below average. This is the WMO forecast:-

The map shows below average precipitation for much of South Asia. The IMD also forecasts below average rainfall.

Of course, in landslide terms we are interested mainly in SW India (Kerala), which has a below average forecast, and the mountainous areas of Pakistan, India, Nepal, Bhutan and Bangladesh. Much of this is also forecast to receive below average precipitation, but note the above average forecast for parts of northern India (Jammu and Kashmir, Himachal Pradesh) and NE India (Sikkim, Arunachal Pradesh). These are some of the most landslide-prone areas of India, suggesting that we may well see substantial landslide challenges in these areas.

The caveat of course is that monsoon-triggered landslides are sensitive to rainfall intensity as well as rainfall magnitude. A below average monsoon can bring intense rainfall events that trigged catastrophic landslides. Unfortunately, the forecasts cannot resolve this issue.

As an aside, the next few days in the European Alps will be interesting. We are about to see a few days of unusually high temperatures, which are likely to drive a wave of snowmelt and permafrost thawing. Given the time of year, this could well trigger extensive rockfall activity.

Unfortunately, by the time I get to Switzerland in nine days the weather is forecast to have reverted to cool drizzle!

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A new paper Fidan et al. (2026) demonstrates that wealth and the rate of land-cover change play a key role in determining the occurrence of fatal landslides in mountain areas. These factors are statistically more significant that precipitation and topography.

A fascinating new paper (Fidan et al. 2026 – this paper is both open access and published under a Creative Commons licence – hurrah!) has just been published in the journal Science Advances that explores rates of land-cover (in the paper, the authors use the term land-use – land-cover) change as a factor in determining fatal landslides in mountains globally. I must admit to some degree of personal interest in this paper, although I am neither an autor nor a reviewer, as it brilliantly uses the dataset that Melanie Froude and I collated on global landslide fatalities (see Froude and Petley 2018). I’m delighted to see our data being used in this way (and please do contact me if you want a copy of the spreadsheet).

Fidan et al. (2026) explores a range of factors that might influence the occurrence of fatal landslides from the perspective of either increased vulnerability (poorer people may live in more vulnerable locations for example) or increased landslide likelihood (land-cover change might increase the likelihood of a landslide being triggered, for example).

The fascinating result lies in land-cover change. The authors have looked at  approximately 60 years of land-cover changes in mountainous areas across 46 countries. Unsurprisingly, there is substantial change, especially in low- and lower-middle–income countries, often involving the loss of forest (which as a first order estimation, may buffer against slope failures), although the pattern is far more complex of course. Fidan et al. (2026) find that a key metric is the rate of change of land-cover, and that this is linked to the rate of population growth (perhaps unsurprisingly). Countries with high rates of population growth also show high rates of change of land-cover.

In many ways, the most interesting figure in this study is in the Supplementary Information. It is a complex diagram, but it’s worth more detailed analysis:-

The main map (A) shows mountain areas with high rates of land-cover change (orange), high density of fatal landslides (blue) or both (black). The left hand graph (B) shows the relationship between the landslide density and the rate of change of land-cover – here, higher rates of land-cover change are associated with a higher density of fatal landslides. The right hand graph is the same data as in (B), but with each point coloured according to the income level of the country. High income countries have a lower fatal landslide density. Thus, as the authors conclude, wealth and land-cover change appear to control fatal landslide density.

There is a really surprising element to this study, which I think requires more consideration. I think I should allow the authors themselves to express this finding, from the abstract:-

“Our statistical analyses show that land-use – land-cover changes have a substantially greater influence on the density of fatal landslides and landslide fatalities than physical factors such as topography and precipitation, especially in lower-income countries.”

As landslide researchers, we almost always default to topography and precipitation as being key in landslide occurrence. There are sound reasons for doing so. But statistically, the rate of land-cover change plays a more important role in mountain areas, especially in poorer countries.

This has (or should have) major implications for the way that we consider and manage landslide risk in such areas.

References

Fidan, S. et al. 2026. Wealth and land-cover change govern landslide fatalities on world’s mountains. Science Advances 12, eaec2739. DOI: 10.1126/sciadv.aec2739.

Froude M.J. and Petley D.N. 2018. Global fatal landslide occurrence from 2004 to 2016. Natural Hazards and Earth System Science 18, 2161-2181. DOI: 10.5194/nhess-18-2161-2018.

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To date news reports suggest two fatal landslides with a combined toll of 17 people.

There are various news reports trickling in about the landslides triggered by the 8 June 2026 M=7.8 earthquake offshore Mindanao in the Philippines. As usual, the remote locations of many of the landslides means that the information is a bit hit and miss at this point.

To date, the most serious event appears to have occurred at a community called New Aklan, located in Glan, Sarangani. It appears that New Aklan is at: [5.7705 N, 125.3356]. News reports indicate that 13 people were killed, although there are also indications of additional fatalities in this area.

A further four people are missing under a landslide at Sitio Buhangin, Barangay Patuco, Sarangani. Patuco is in the area of [5.4770, 125.4859]. This appears to have been a failure on a coastal cliff:-

Over the next few days, satellite imagery should become available that will help identify the landslide impacts, but in the meantime Dan Shugar has identified some (using Planet imagery, I’d imagine):-

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Initial analyses suggest that the earthquake this morning has the potential to have triggered significant numbers of landslides and areas of liquefaction.

At the time of writing, the impacts of the M=7.8 earthquake that occurred offshore the south coast of Mindanao in the Philippines remain unclear. Initial reports in the local press suggest 15 fatalities so far, but as always it could be the case that there is no information from those areas most seriously impacted.

The USGS Pager site is the best source of information about potential landslide impacts, bearing in mind there is a high level of uncertainty. This estimates that the area exposed to landslides is at the high end of the “significant” scale and that the population exposed to landslides lies in the 1,000 to 10,000 people range. This is the Pager landslide hazard map:-

The area with the highest level of landslide hazard is remote and rural, so we may not get good information from this area for a while.

The potential for liquefaction may be even more serious, with a broad swathe having a high level of hazard:-

Past earthquakes have generated large liquefaction-related landslides on low angle slopes, with devastating effects. Hopefully, there won’t have been an event on this scale in Mindanao.

One final point to note is that the Philippines is just entering the typhoon season. Fortunately, Mindanao is sufficiently far south to be away from the main typhoon zone. However, these storms are so large that they can bring very heavy rainfall – see for example Typhoon Bopha in 2012. A similar event this year could have very significant consequences.

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Source: Water Resources Research

Wildfires can increase flooding risks in and downstream of burned areas by removing vegetation and disturbing hydrologic processes. As the climate changes, the severity of both wildfires and heavy rainfall events is increasing, meaning flooding is likely to become more severe in the near future. Better understanding how, and by how much, wildfires change flood risk is important for disaster and infrastructure planning for communities around the country.

Canham and Lane used streamflow data from the U.S. Geological Survey’s National Water Information System and precipitation data from the NOAA Analysis of Record for Calibration product to identify storms and quantify their effects across seven burned watersheds in the western United States.

To make the most of the limited data on flooding in the years following wildfires, the researchers created a paired-storms framework: They identified postfire peak flows (PFPFs), defined as the five highest peak flows within 3 years of a wildfire across seven watersheds. Then, for each precipitation event causing a PFPF, they looked for storms with similar characteristics (or paired storms) that occurred before the wildfire. Storm characteristics used for pairing included the season in which the storm occurred, recent precipitation, and precipitation depth, duration, and peak intensity.

The researchers found significantly elevated peak flows after wildfires in many cases, underlining the risks to communities following wildfires and validating their approach for use elsewhere.

Altogether, the authors found 26 PFPF events, including 20 with paired storms occurring before wildfires. For 75% of the postfire storms, their peak flows were 2 or more times greater than prefire peak flows. PFPFs were most likely to happen in the first year after a wildfire and typically occurred following storms that were centered upstream of the watershed centroid, were uniform in shape, and fully covered the watershed and burned area, the authors reported. They also found some evidence that the first storm in the year immediately following a fire has a higher-than-expected chance of producing a PFPF.

Future work could look more deeply at the characteristics of storms occurring over burned areas, such as storm direction and watershed recovery, and could apply the automated methods to more burned watersheds and storm events to enhance the robustness of the work, the authors say. (Water Resources Research, https://doi.org/10.1029/2025WR040693, 2026)

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2026), How wildfires worsen flood risk, Eos, 107, https://doi.org/10.1029/2026EO260133. Published on 30 April 2026.

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New evidence from the Natural Hazards Commission – Toka Tū Ake (NHC) shows that landslides are now New Zealand’s most costly natural hazard.

New Zealand is a country that is prone to a range of natural hazards. Located on a series of major fault systems, earthquakes cause high levels of loss. The country is also volcanically active, with occasional tragedies. Heavy rainfall brings floods.

To share the cost of these perils, following the 1942 Wairarapa earthquakes, the New Zealand government established the Earthquake Commission (EQC) in 1945, initially focusing on earthquakes and war damage, but subsquently expanded to cover other natural hazards.

In the subsequent years, the EQC has evolved into the Natural Hazards Commission – Toka Tū Ake (NHC), with a purpose “to reduce the impact of natural hazards on people, property, and the community”. Essentially it operates as a financial pool, with home owners paying a levy on top of their insurance to generate the fund. In the event of a loss, the fund pays for the rebuild costs up to a cap (currently NZ$300,000); the remainder is then covered by the property’s insurance. Claims are funded directly from the pool, with reinsurance cover and ultimately a government guarantee in place to ensure that there are sufficient funds.

In reality, NHC does much more than this, acting to manage and settle claims, and to understand the range of hazards to which New Zealand is prone.

In the last few days, a range of media outlets in New Zealand have been reporting new data from NHC about losses from natural hazards in New Zealand. This is the headline from 1News:

“Landslides are New Zealand’s most expensive natural hazard – and new data reveals a sharp rise in damage claims and growing risks to homes, infrastructure and communities.”

In total, since 2021 NHC has received 13,000 landslide claims and has paid out NZ$322 million (US$191 million). New Zealand is seeing an abrupt increase in landslide losses, driven primarily by increasingly frequent high magnitude rainfall events. NHC is urging property owners to undertake preventative maintenance and to be aware of the limitations of EQC cover.

In common with many other places, these landslide hazards represent a major challenge to New Zealand. The landscape has many dormant landslides that are being reactivated by these increased rainfall events, and many new failures are also occurring. But, generating reliable risk maps for landslides remains a major challenge. This needs to be a major research focus in the coming years. It will require better understanding of triggering events (rainfall and earthquakes primarily); of the initiation processes within the slope; of runout / debris mobility; and of vulnerability and consequent losses. It is probably true to say that in all of these areas, landslide research lags behind that of earthquakes and floods, primarily because of a lack of long term investment.

In many countries, landslides are not an insured risk for this reason. On its own, this will be a major challenge that must be addressed. For those countries in which landslides are insured, we need quickly to get up to speed.

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In April 2026 I recorded 36 fatal landslides causing 90 fatalities, the lowest monthly total for 2026 to date.

This is my regular update for the number of fatal global landslides, focusing on March 2026. As usual, this data has been collected in line with the methodology described in Froude and Petley (2018) and in Petley (2012). References are listed below – please cite these articles if you use this analysis. Data presented in these updates should be treated as being provisional at this stage as I will reanalyse them prior to formal publication, and other events will emerge.

The headline figures are as follows:

March 2026: 36 fatal landslides causing 90 fatalities;

This is an interesting result, unusually showing that fatal landslides in April were substantially lower than for any of the preceding months in 2026. This is the updated annual chart by month:-

Loyal readers will know that I like to present the running total using pentads (five day blocks). This is the cumulative total pentad graph to the end of Pentad 24 (which captures all of the events to the end of April):-

Thus, whilst April 2026 was unexceptional compared with the previous months of this year, the number of fatal landslides was still above the long term mean. Overall, 2026 continues to run extremely hot, exceeding even the record-breaking year of 2024.

We now start to enter the crucial period of much higher global fatal landslide occurrence. Whilst in the long term dataset this acceleration typically occurs in June (or even July), in recent years it has happened in May, as the 2024 line shows. I will watch with great interest to see what happens this month.

As I always stress, the occurrence of fatal landslides prior to the South and East Asia rainy seasons is not a predictor of what will happen in that period. Interestingly, the WMO is forecasting a below average summer monsoon in South Asia.

References

Froude, M. and Petley, D.N. 2018.  Global fatal landslide occurrence from 2004 to 2016.  Natural Hazards and Earth System Sciences 18, 2161-2181.

Petley, D.N. 2012. Global patterns of loss of life from landslides. Geology 40 (10), 927-930.

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Ten people were killed in a large landslide in Papua New Guinea triggered by heavy rainfall associated with Tropical Cyclone Maila.

On 9 April 2026, a large landslide occurred at Lamarain in the Inland Baining LLG of Gazelle District in Papua New Guinea. The landslide was triggered by heavy rainfall associated with the passage of Tropical Cyclone Maila.

Media reports indicate that ten people were killed by the landslide and that a further 18 people were injured. Baining is located at [-4.2548, 151.7811], so I assume that this is the general area.

Gaining information about landslides in the remote areas of Papua New Guinea is very challenging – the terrain is rugged and there is a high level of civil turmoil. But the best source of information is on the Facebook page of NBC East Britain, which has posted a helicopter video of the aftermath. This is a still from that video:-

There are several interesting aspects of this landslide. First, the failure appears to have initiated high on the hillslope in an area that has a mix of forestry and cleared areas. The source appear to be quite large and deep-seated. This has transitioned into a disrupted debris slide / avalanche with a substantial amount of entrainment.

Note also the multiple other landslides in that area, all fresh, suggesting that the intense rainfall was sufficient to drive widespread failures. It is interesting to note though that is event did not involve multiple shallow landslides that combined to create a channelised debris flow.

The Post Courier reports that the Lamerain landslide occurred in two phases, the first at 6 am on 9 April 2026 and the second 24 hours later. However, other reports suggest that it occurred on 12 April 2026, underlying the challenges of properly understanding landslides in Papua New Guinea.

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A new study (Vega et al. 2026) shows that patterns of reported structural damage in Medellin are probably caused by deep-seated deformation driven by a series of ancient landslides under the city.

Medellin is the second largest metropolitan area in Colombia, with a population of around 4 million people. It has grown rapidly, expanding into the surrounding hillsides, with many unplanned and informal communities on steep slopes. Landslides are a common problem.

The rapid rate of growth has been accompanied with many reports of structural failures in buildings, with a general (and not unreasonable) assumption that these are associated with poor construction quality. But a fascinating new study (Vega et al. 2026) in the journal Landslides challenges this assumption in a most interesting way. The headline from the study is that there is a strong correlation between areas that have a high density of reports of structural damage and ground deformation driven by large, deep-seated landslides.

Vega et al. (2026) have used InSAR to map ongoing displacements across Medellin. In three key areas (Doce de Octubre, Manrique and Villa Hermosa) they detected high rates of ground deformation. They were able to show that these areas correspond to mappable deep-seated landslides. An example is in the Manrique neighbourhood of Medellin:-

Interpretation of pre-urbanisation imagery suggests that the topography underlying Manrique includes a series of deep-seated landslides. The InSAR data indicate that these areas are actively deforming, and these deformation zones correspond to areas with a high density of reports of structural damage. Interestingly, the density of damage reports does not correlate with the style of construction of the buildings.

Vega et al. (2026) also note that many of the recent acute landslide events in recent years also lie within these areas of high underlying ground deformation. Fore example, the 24 June 2025 landslide that killed 27 people lies within an area highlighted by the InSAR analysis.

This study highlights two key things for me. First, it is a novel and interesting application of InSAR in an urban setting, allowing the underlying processes that are driving structural damage in the city to be understood. Second, the study highlights the underlying vulnerability of Medellin to deep-seated slope processes. As the climate continues to change, and human processes modify the landscape and the groundwater, management of these slopes would seem to be a high priority.

Reference

Vega, J., Aristizábal, E., Ospina, A. et al. 2026. Neighbourhoods in motion: unveiling the drivers behind structural damage hotspots in Medellín (Colombia). Landslides (2026). https://doi.org/10.1007/s10346-026-02758-1

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On 19 July 2025, intense, long duration rainfall triggered over 550 landslides in Sancheong, South Korea, killing at least 10 people.

On 19 July 2025, extremely heavy rainfall triggered multiple landslides in Sancheong, South Korea. This event has been described by a new paper (Nguyen et al. 2026) just published in the journal Landslides. The paper is behind a paywall, but this link should give you access at the time of writing.

The core of the affected area is at [35.4333, 127.9111] (as usual, Landslides provides the location in degrees minutes and seconds when digital degrees is so much more useful – a pet frustration of mine!). This is a Planet Labs image of a part of the area, captured before the event. The marker is at the coordinate noted above:-

And this is the same area after 19 July 2025:-

And here is a slider to allow a comparison:-

Nguyen et al. (2026) have mapped 568 individual landslides triggered by this rainfall event, triggered by rainfall in the range of 498 – 619 mm over a c. 55 hour period. These landslides killed at least 10 people and caused damage to homes and infrastructure. It is estimated that the restoration costs are in the order of US$800 million.

In common with many other events of this type, the landslides are mainly shallow, translational failures in soil or regolith on steeper slopes. As I have frequently noted, such terrain is very susceptible to unusually intense rainfall events, which often trigger a cluster of landslides in close proximity. These often merge to form channelised debris flows. Nguyen et al. (2026) note however that their modelling indicates that it was a combination of the intensity of the rainfall and its duration that led to these failures.

As rainfall intensities increase due to climate change, we are seeing increasing numbers of these landslide clusters. I greatly welcome studies such as Nguyen et al. (2026) , which allow us to build understanding in each case.

Reference and acknowledgement

Nguyen, H.H.D., Song, C.H. & Kim, Y.T. 2026. Physically based data-driven analysis for large-scale investigation of the July 2025 rainfall-induced landslide in Sancheong, South Korea. Landslides. https://doi.org/10.1007/s10346-026-02778-x

Planet Team 20246. Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/

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A new study (Sun et al. 2026) shows that in six earthquakes in China between 2010 and 2022, landslides and rockfalls were responsible for at least half of the total fatalities.

It is well-established that landslides are a major cause of loss of life in earthquakes in mountainous areas. The seismology maxim that “it is not earthquakes that kill people, it’s collapsing buildings” does not apply in its pure form in mountains – landslides also kill large numbers of people.

However, the actual number of people killed by landslides in earthquakes is poorly understood. This is largely due to the challenges of collecting reliable information in the aftermath of a major earthquake, when the focus is on rescue and recovery rather than data collection. For this reason, many studies of landslide fatalities do not include seismically-triggered events. This is true of my own work.

However, a study has just been published (Sun et al. 2026) in the journal Natural Hazards Review that starts to address this issue. The paper nominally examines fatalities from all causes from earthquakes in China from 2001 to 2022. However, the authors note that the data has low reliability until 2010, so I’ll focus on the period from 2010 to 2022. I also note that the authors use the term “geological hazards“, which is a little broader than landslides. I should note that the paper isa broad look at fatalities from earthquakes – there is a much richer range of analyses than I will cover here.

In the period from 2010 to 2022, Sun et al. (2026) identified 14 earthquakes in which geological hazards caused loss of life. In some cases, the impacts were substantial. Thus, the M=6.5 3 August 2014 earthquake at Ludian in Yunnan led to 134 fatalities and 40 people missing from geological hazards from a total of 728 fatalities (c.24 % of the total), whilst the 5 September 2022 M=6.8 earthquake at Luding in Sichuan led to 76 geological hazard fatalities and 25 missing from a total of 118 fatalities (c.86% of the total). In six of the 14 examples, geological hazards caused at least 50% of the fatalities.

Sun et al. (2026) highlight that “fatalities from geological hazards concentrate in geologically complex, mountainous provinces, i.e., Sichuan, Yunnan, Gansu, Guangxi, and Guizhou”. They note that even small events can trigger fatal landslides – for example, six people were killed in a rockfall triggered by a M=4.3 earthquake in Guizhou in 2010, whilst a M=2.8 aftershock from the Yanjin earthquake in 2006 triggered a rockfall that killed a person.

This is an incredibly useful study. It starts to shed light on the impact of landslides in large earthquakes. It is not the definitive study, and questions remain – not least, the pattern of landslide losses in very large earthquakes, like the 2010 Wenchuan event, in which landslides were ferocious. But it forms the basis for such investigations, starting to fill a major gaps in our understanding.

Reference

Sun, B. et al. 2026. Causes Analysis of Earthquake-Related Deaths in Mainland China 2001–2022. Natural Hazards Review, 27 [2]. https://doi-org.ntu.idm.oclc.org/10.1061/NHREFO.NHENG-2458

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