Zhouqu, China, disaster - data capture, modelling and preliminary geohazard assessment
Lead Research Organisation:
University of Portsmouth
Department Name: Sch of Earth & Environmental Sciences
Abstract
At 1am on Sunday the 8th of August a large flow slide took place in Zhouqu, a county town in SW Gansu Province, China. Current information suggests that the trigger was a rainfall event delivering a reported 97mm in less than 40 minutes (annual precipitation averages from 400 to 900mm). Antecedent rainfall may also have played a role. The devastating event caused the deaths of more than 1000 people (1,144 as of Friday 13th of August in Zhouqu alone with at least 600 people still missing). In the wider region, mudslides and debris flows continue to affect the local population with further fatalities in Longnan (south and downstream of Zhouqu) and Tianshui (to the northeast). The region is characterised by a seismically active mountainous terrain, an extension zone of the Tibetan uplift, and was affected by the Wenchuan earthquake (12/5/2008) that generated and re-activated a large number of landslides. At Zhouqu, the local erosion base is formed by the Bailong River at about 1300m asl. The surrounding peaks reach heights of about 3500 to 3750m. The catchment where the sediments originate is approximately 20km2 and is characterised by very steep slopes. Vegetation cover is sparse with only a small remnant of upland forest cover remaining. Following the disaster a lively debate has sprung up apportioning blame to deforestation, hydropower development and mining in the area. In order to learn lessons from this kind of events, instead of speculation, a scientific approach is required to collect data, verify their robustness and make impartial observations and develop reliable process models that will be essential to develop appropriate mitigation strategies for the future. The site was visited in November 2009 by Dijkstra and Gibson and discussions were held with the government of Zhouqu about the risk posed by large landslides in the area. It is vitally important to collect data soon. As with all landslide events, an understanding of local geological structure, drainage, morphology and geotechnical parameters are essential in building a robust model of landsliding (e.g. Geertsma et al. 2006). The key characteristics of landslides and landslide dams in this region are often removed rapidly by the very instability that causes them. It is inherently difficult to map out the potential for landslides to transfer into catastrophic viscous flows with complex and transient mechanical and rheological interactions. However, this is an essential component in any reliable assessment of the risks. These sort of assessments are rare because of the scarcity of events available for this type of research. When these occur we must make the most of it. Mostly, our understanding of these processes is derived from small-scale laboratory experiments, requiring upscaling that may affect the relevance of the observations. In this case, a unique field laboratory is waiting to be explored to gain a better understanding of the risks posed by geohazards to the population in this region.
Organisations
- University of Portsmouth (Lead Research Organisation)
- British Geological Survey (Collaboration)
- LOUGHBOROUGH UNIVERSITY (Collaboration)
- Transport Research Laboratory Ltd (TRL) (Collaboration)
- Lanzhou University (Collaboration)
- Natural Environment Research Council (Collaboration)
- National Natural Science Foundation of China (Collaboration)
Publications
Dijkstra T
(2012)
Geomorphic controls and debris flows - the 2010 Zhouqu disaster, China
in Proceedings of the 11th International Symposium on Landslides
Description | There is significant uncertainty regarding risks posed by channelised debris in the Bailong Corridor. VNIR techniques demonstrate considerable potential for reducing such uncertainties and improving knowledge of debris movement, debris origin and landscape evolution. The nature and triggers for the Zhouqu debris flow disaster were identified, described and published. |
Exploitation Route | A great deal more work is required to improve models of how to better understand debris production and movement in mountainous regions. This work demonstrated that field investigation is necessary and that suitable remote sensing techniques can yield appropriate information. |
Sectors | Construction Environment Transport |
Description | Chengdu Workshop |
Organisation | Natural Environment Research Council |
Country | United Kingdom |
Sector | Public |
PI Contribution | Travel to, participation and presentation at collaborative workshop |
Collaborator Contribution | NERC/ESRC funded travel |
Impact | None as yet |
Start Year | 2014 |
Description | Lanzhou Arid Environment and Climate Change |
Organisation | Lanzhou University |
Country | China |
Sector | Academic/University |
PI Contribution | Visiting Position and Informal Agreement on Future Collaboration |
Start Year | 2009 |
Description | Lanzhou University |
Organisation | Lanzhou University |
Country | China |
Sector | Academic/University |
PI Contribution | Agreement to spend at least 2 weeks in Lanzhou area of China per year 2015-17. |
Collaborator Contribution | Travel costs, accomodation costs and facilities costs will be borne by partner |
Impact | Promotion of committment and goodwill |
Start Year | 2014 |
Description | Lanzhou University Institutional Collaboration |
Organisation | Lanzhou University |
Country | China |
Sector | Academic/University |
PI Contribution | I hosted a visit and workshop between the Leadership Team of Lanzhou University to Leadership Team of University of Portsmouth. |
Collaborator Contribution | Travel to and attendance at workshop to discuss and promote institutional level memorandum of understanding |
Impact | Draft memorandum of understanding is currently in negotiation |
Start Year | 2014 |
Description | NIR Spectroscopy of Chinese Debris Flows |
Organisation | Lanzhou University |
Country | China |
Sector | Academic/University |
PI Contribution | XRD and VNIR spectral analyses of landslide debris |
Collaborator Contribution | Collection and supply of landslide debris from difficult to access debris flows China |
Impact | Peer-reviewed scientific paper is in production at present |
Start Year | 2014 |
Description | NSFC |
Organisation | National Natural Science Foundation of China |
Country | China |
Sector | Public |
PI Contribution | Attendance and presentation at workshop |
Collaborator Contribution | Accomodation, in-country travel and VISA sponsorship |
Impact | None yet |
Start Year | 2014 |
Description | White Dragon III |
Organisation | Transport Research Laboratory Ltd (TRL) |
Country | United Kingdom |
Sector | Private |
PI Contribution | Funding application to directed NERC CALL IRNH. My team led 2 work packages. |
Collaborator Contribution | TRL staff led a work package of the proposal. |
Impact | Application was shortlisted but unsuccessful |
Start Year | 2015 |
Description | White Dragon Proposal |
Organisation | British Geological Survey |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Grant submission to directed NERC call IRNH. My team led 2 of the workpackages. |
Collaborator Contribution | Bid IP was Dr Tom Dijkstra ,British Geological Survey who led bid development and editing. |
Impact | Grant Application was shortlisted, but not successful. |
Start Year | 2014 |
Description | White Dragon Proposal II |
Organisation | Loughborough University |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Funding application to directed NERC CALL IRNH. My team led 2 work packages. |
Collaborator Contribution | LU staff led a collaborative work package |
Impact | Application was shortlisted but unsuccessful |
Start Year | 2015 |
Description | What caused the 2010 Zhouqu Landslide Disaster? |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Open Research Seminar, promoted discussion of Chinese collaboration I have started collaboration with Peter Brett Associates with respect to a potential karst database for central China |
Year(s) Of Engagement Activity | 2012 |
Description | What caused the Zhouqu Debris Flow Disaster |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | Yes |
Geographic Reach | Regional |
Primary Audience | Professional Practitioners |
Results and Impact | Research seminar and public lecture, has promoted nkowledge of disasters in this region I have been invited to join the Speakers for Schools Programme |
Year(s) Of Engagement Activity | 2011 |