Characterising the post-seismic behaviour of damaged slopes - Nepal 2015

Lead Research Organisation: Durham University
Department Name: Geography


The intense ground-shaking experienced during the 2015 Nepal earthquakes triggered over 3,000 landslides, and left many other mountain slopes heavily damaged. The earthquakes occurred in the winter dry season, a period that is year-on-year relatively inactive in terms of landsliding. Over 80% of rainfall in Nepal occurs in the monsoon, and as a result over 90% of fatal landslides also occur during this period. The risk of destabilizing heavily-damaged slopes that have extensive networks of cracks - that may develop into landslides during the monsoon - needs to be fully understood. The basic understanding of landslide mechanisms, and in particular the behaviour of slopes and landslides after earthquakes, is at present limited by a lack of direct observations of how slopes and landslides change in the months that follow.

In this project, working in collaboration with colleagues at the National Society for Earthquake Technology in Nepal, we aim to collect a unique dataset on the changes to cracked slopes during the forthcoming monsoon rainfall. By monitoring landslide movement and how this responds to the monsoon rains, we aim to develop a] new understanding of which types of slopes remain stable, and which continue to move and develop further landslides. Based upon our previous research on landslide mechanics, we will use this data to consider possible future styles of movement and controls upon this process, with a view to improving our understanding of landslide movement, but also to feed directly into earthquake-triggered landslide hazard and risk assessment, both immediately in Nepal, and more widely to other regions that may face similar hazards in the future.

Planned Impact

Our proposal seeks to address a scientific gap in understanding of slope failure mechanics. A stark practical demonstration of science's relatively poor understanding of post-earthquake (EQ) landslide risk and action based upon this is the lack of a landslide equivalent of the earthquake 'Duck, Cover, Hold' protocol. We argue that this is rooted in a lack of science on how slopes are likely to behave after earthquakes, and how we should manage the risks they pose. This is despite the relative familiarity with landsliding resulting from pervasive rainfall-triggered landslides during each monsoon in S Asia. Whilst we will seek to maximize immediate impacts to Nepal at every opportunity, the greatest impacts are likely to be gained from our analysis of the slopes during the months after the EQ. Our findings will be beneficial in mitigating landslide risk in future earthquakes in countries with similar EQ and landslide hazards. We anticipate the following outputs, with the potential for impact: A tool-kit for responsive monitoring EQ-damaged landslides; Evidenced-based guidelines on the performance of EQ-damaged slopes; Capacity-building of local specialists in landslide monitoring; Long-term monitoring of post-EQ slopes beyond the end of the project; and, Scientific outputs on EQ-triggered landslide mechanics and hazards.
We will conduct the following to maximise the potential for impact:
1) Hold a workshop in Nepal to share the findings with: key stakeholders in the communities in the Upper Bhote Koshi Valley; district and village-level government officials and humanitarian/development professionals in Sindhupachok; national level government; and, the development community in Nepal. We will aim to share our data and interpretation to underpin a tailored analyses for each group. The outcome will be greater awareness of the potential insight gained from monitoring for landslide disaster risk reduction.
2) We will develop training materials explaining how to monitor slopes. The research will enable us to install equipment across a limited number of sites but there is scope for stakeholders to install similar systems in other locations. We will work with NSET who have extensive experience in public engagement across S Asia.
3) Our primary pathway for impact will be via the Nepal Risk Reduction Consortium's Communications Group. The NRRC draws together humanitarian and development partners with financial institutions in partnership with the Government of Nepal to reduce Nepal's vulnerability to natural disasters. Possible outlets for our toolkit include the NRRC's 'Be Prepared' platform: We have engaged with NRRC during the EwF Project, and since the 2015 EQS. The outcome will be greater awareness in Nepal of possible post-EQ landslide failure trajectories and mechanisms to collect data to assess this.
4) Via collaboration with our extensive partner network in Nepal and S Asia, we will disseminate our findings to donor agencies, UN organisations, NGOs and local government to better understand landslide process, mechanisms, and possible future slope behaviour. Realistically, the data is a first step in better understanding these processes, but we anticipate that during the monsoon useful field data to inform decision making on slope failure risks will become available. The outcome will be enhanced links between the UK researchers and key organisations in Nepal.
Beyond Nepal, we will look to develop a Case Study for the UNISDR STAG (Science and Technical Advisory Group) on landslide disaster risk reduction (see: This will include information on monitoring slopes following earthquakes and data interpretation. We will share examples with the popular humanitarian news network, IRIN. The outcome will be a freely available case study on the project, the methods for slope monitoring and the interpretation of the data gained.
Description Monitoring instruments were installed on slopes damaged by the 2015 earthquakes in Nepal. During the summer monsoon in 2015, these slopes presented an unknown risk of further failure and collapse. To date, the monitoring data shows limited additional movement. However, the 2015 monsoon was relatively weak, and it is expected that future movements may occur in coming monsoon seasons. Analysis of satellite images also show multiple landslides in the area of the monitoring equipment.
Exploitation Route Our monitoring equipment is now being maintained by the National Society for Earthquake Technology in Nepal who will continue to collect data over coming years. The insight gained from this instrumentation has been used to inform advice provided to DFID and the UN in Kathmandu on the risks posed by future land sliding in the 14 districts that were heavily impacted by the 2015 earthquakes.
Sectors Environment

Description Findings from our monitoring work undertaken in this project have been used by DIFD and the UN in Nepal to guide decisions on the reconstruction efforts in the 14 districts heavily impacted by the 2015 earthquakes. More recently, as the earthquake reconstruction process has rolled out, the insight from our monitoring has been used by the National Reconstruction Authority to inform the assessment of nascent geohazards facing communities. Continued monitoring will be used to provide further insight, and to inform future disaster risk reduction planning in Nepal.
First Year Of Impact 2015
Sector Environment,Government, Democracy and Justice
Impact Types Societal

Amount £326,000 (GBP)
Funding ID n/a 
Organisation Government of the UK 
Department Department for International Development (DfID)
Sector Public
Country United Kingdom
Start 04/2017 
End 03/2019
Description Collaboration in GCRF-funded project on citizen science for community based disaster risk reduction 
Organisation University of East Anglia
Department School of Environmental Sciences UEA
Country United Kingdom 
Sector Academic/University 
PI Contribution This is a joint project to explore the use of and to define best practice for citizen science in disaster risk reduction at the community level for geohazards. Our group is contributing from experiences using citizen science on landslides triggered by earthquakes, based upon our monitoring work in Nepal.
Collaborator Contribution The wider project concerns citizen science expertise from across a range of geoscience, engineering and social science research backgrounds.
Impact In process.
Start Year 2017
Description Co-lead of the CEOS (Committee on Earth Observation Satelites) Disasters working group - landslides, Nepal Case Study 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Set up and roll out of Landslide case study for the CEOS Disasters Working Group, which advocates for wider use of earth observation data. The case studies showcase possible applications of EO data, and here build upon our research in Nepal on landslides.
Year(s) Of Engagement Activity 2016,2017