Post-Disaster Archaeological Investigations in the Kathmandu Valley UNESCO World Heritage Property (Nepal)
Post-Earthquake Rescue Archaeology in Kathmandu
A research project of the Department of Archaeology.
The two major earthquakes that struck Nepal on the 25th April and the 12th May 2015 were a human catastrophe, devastating large areas of the county and neighbouring regions, leading to substantial loss of life and livelihoods as well as post-disaster physical and mental trauma. This natural disaster and associated aftershocks also generated a cultural catastrophe, damaging and destroying much of Nepal’s unique cultural heritage, including monuments within the Kathmandu Valley’s UNESCO World Heritage Site of Universal Outstanding Value. Not only beautifully ornate temples of wood, brick and tile, the monuments of the Kathmandu Valley represent a major source of income and economic growth through international and national tourism and are a key component of Nepal’s fragile economy as one of the country’s major sources of foreign currency. Furthermore, these sites play a central role in the daily lives of thousands, representing portals where the heavens touch the earth and where it is possible for ordinary people to reach out and commune with their guiding goddesses and gods – they are of intangible value.
For these reasons, the damaged heritage sites of Nepal are currently subject to a major program of consultation, reconstruction and conservation. Prior to rebuilding, an international team of archaeological and architectural experts from the Department of Archaeology (Government of Nepal) and Durham University, along with partners, including the University of Stirling, M.S. University of Baroda, Austrian Academy of Sciences, University of La Trobe and Pashupati Area Development Trust, are implementing multi-disciplinary evaluations and assessments of collapsed monuments within the damaged Durbar, or palace, Squares of Patan, Hanuman Dhoka and Bhaktapur as well as the temple complex of Pashupati.
The project is funded by the following grants.
- Unesco 2015 Ext: Archaeological Identification, Evaluation And Interpretation Of Thekathmandu Valley World Heritage Property (£27720.70 from UNESCO)
- Can We Rebuild The Kasthamandap? Promoting Post Disaster Excavations, Salvageand Subsurface Protection Protocols In Kathmandu (£61020.48 from AHRC)
- Post-disaster Archaeological Excavations At Jagannath And Gopinath Temples At Hanumandhoka Durbar Square In The Kathmandu Valley World Heritage Site (£11314.19 from UNESCO)
There is a real danger that further damage will be inflicted on these monuments of Outstanding Universal Value in the rush to rebuild the monuments quickly. This is because many plans for rapid reconstruction have focused on architectural superstructures and have not contemplated the possibility of the presence of earlier structural remains and human activity below the current ground level. The necessity for assessment of the presence of such remains is critical as plans to reconstruct temples on existing ruined platforms should first be preceded by a phase of rescue excavations to evaluate the subsurface stability of the monument’s foundations and assist in understanding why they collapsed. Such interventions can then inform the structural engineers and architects tasked with reconstruction by providing detailed scientific recording and analysis as few studies currently consider subsurface remains in the Kathmandu Valley. The lack of engagement with subsurface remains is a concern as plans to sink deep foundations, utilising inauthentic materials such as steel and concrete, could cause a second cultural catastrophe – the irreversible destruction of the Kathmandu Valley’s earlier historical and archaeological record.
In reaction to this context, our project pilots the characterisation and scientifically dating of the developmental sequence and presence of earlier cultural phases at sites within the Kathmandu Valley UNESCO World Heritage Site. The identification of this heritage will lead to the creation of Archaeological Risk Maps, for site managers to guide future development and infrastructure interventions for sustainable development. The project also evaluates the nature and condition of the foundations of collapsed monuments to assist the preparation of plans for their reconstruction. During the fieldwork, we have offered training in rescue and urban archaeology including the post-disaster analysis and evaluation of monuments, as well as co-producing with partners, post-disaster methods and protocols to enable the protection of heritage alongside rapid humanitarian responses during the emergency phase of an earthquake rescue.
A multi-disciplinary team co-led by Durham University and the Department of Archaeology, Government of Nepal (DoA), undertook pilot post-disaster rescue excavations and surveys in 2015 and 2016 with funding from UNESCO (Contracts 4500283215 & 4500318125) and an Arts and Humanities Research Council (AHRC) Global Challenges Research Fund grant (AH/P006256/1) and a National Geographic Society Conservation Award (#C333-16); with field support from the Pashupati Area Development Trust (PADT), Department of Archaeology as well as Bhaktapur, Kathmandu and Patan Municipalities.
Activities and Results from 2015
Conducted between October and November 2015, the mission focused on the three major Durbar Squares of the Kathmandu Valley: Hanuman Dhoka, Patan and Bhaktapur. The team used various techniques, including excavation, Ground Penetrating Radar (GPR) and geoarchaeology to identify subsurface archaeology and also understand the historical and environmental development of these historic city squares, whilst also assessing damage to the foundations of collapsed monuments.
Geophysical survey, using Ground Penetrating Radar (GPR) was conducted across the Durbar Squares prior to excavation. GPR survey enabled the identification of the depth and extent of subsurface archaeology under the current brick paved squares. In combination with excavation, the team are used the GPR results to create Archaeological Risk Maps of the heritage within the three Durbar Squares, providing a detailed layout of archaeological features such as walls and buildings below the current ground level. Excavations across Bhaktapur Durbar Square identified several of these walls, clearly demonstrating the presence of earlier structures within this historic site. Identification of subsurface archaeology is critical for guiding the placing of new water, power and sewerage infrastructure, new pilgrim and tourist amenities as well as informing the design of new foundations for collapsed monuments.
This is of critical importance as the team found that many modern pipes had already cut through archaeological deposits, and excavations affirm the need for archaeological watching briefs prior to any interventions at these World Heritage Properties. They also demonstrate the potential of Archaeological Risk Maps to inform the enhanced management and long-term protection of these sites for sustainable development, with research providing a greater understanding of how monuments developed facilitating their enhanced rehabilitation and future protection. The presence of earlier phases of human activity below the current paved Squares suggests that the layouts of these Durbar Squares have gradually developed over time, potentially in responses to past earthquakes and programmes of construction, with the current standing monuments the most recent architectural expressions, rather than representations of the earliest configuration of these sites.
Adjacent to structures the team identified earlier monumental phases, such as a timber and clay platform at the Char Narayan Temple at Patan, and several phases of brick and stone temple construction at the Vatsala Temple at Bhaktapur. At Hanuman Dhoka, the team focused attention on the Kasthamandap. Kathmandu’s eponymous monument, it has become an icon of the Valley’s lost heritage after the 2015 earthquakes. Here, as in Patan and Bhaktapur, it was found that the foundations of the monument were resilient and undamaged by the 2015 earthquakes or previous seismic events. Indeed, the majority of damage to the foundations of the Kasthamandap was caused by immediate post-disaster rescue interventions. Though understandable and undertaken in haste, with a priority of recovery of the injured and dead, more recent interventions from non-emergency activities have damaged some monuments without recording, destroying the above and below surface heritage of Kathmandu. Detailed recording and methodical excavation at the Kasthamandap began to reconstruct contributing factors to the monument’s collapse, with a suggestion that it may have been linked to superstructure maintenance issues. Indeed, at this monument, some architectural elements, such as saddletones to lock in supporting timber pillars, were missing and some wooden pillars were also missing key features such as interlocking tenons.
In addition to identifying the strength of the foundations at the Kasthamandap, we also began to trace their layout and sequence. From the pilot excavations in the southwest corner, we identified that the 2 metre deep foundations were linked to large brick piers, which held the large central saddlestones, which supported the main superstructure of the monument. Between the piers and the foundation ran bracing cross-walls, which we believed may have formed a regular grid, creating a mandala of nine-cells. Within the three central saddlestones visible, the team also discovered gold foil mandalas. Such objects are relatively rare and linked to the foundation design, probably relate to elaborate construction rituals and the creation of cosmological significance. Dating the foundations and brick piers to 700 CE through Optically Stimulated Luminescence dating, and the cross-walls to 900 CE, the excavations not only revealed the symbolic connotations of the Kasthamandap’s design, but also its complex development and renovation, with its origins some 500 years earlier than traditionally assumed. Further geoarchaeological analysis will also provide evidence on the nature of the Kathmandu Valley’s past environmental development and how urbanisation was affected by and affected these changes.
The first season of activities illustrated the dynamic histories and development of the three Durbar Squares. The fieldwork also informed architects and engineers as to the integrity of the foundations of the collapsed monuments, illustrating the resilience of traditional construction techniques through the centuries within a seismically active region. However, several questions remained, particularly at the Kasthamandap. Whilst we had demonstrated the traditional design of the foundation wall in the southwest and its strength, we had not looked in detail at the area of the missing central saddlestone to the northeast, and confirm whether this had impacted on structural stability whilst also exposing the full architectural plan of the foundations, making it possible to confirm the presence of the nine-celled mandala across the monument.
Activities and Results from 2016
To answer the questions posed in 2015, funding from the AHRC’s Global Challenges Research Fund allowed for the further investigation of the Kasthamandap. Removing rubble from across the entire monument to expose its surviving foundations and floor levels, we identified that heavy machinery had ripped away substantial portions of the foundation wall and outer wall of the monument to the south, east and west, which had survived the earthquake. With the removal of twentieth century floor surfaces, we identified that the foundation formed a square of 12 by 12 metres, and enclosed four brick piers, as had been postulated in 2015. The removal of the tiled surface also revealed the ‘missing’ northeast saddlestone, which was also undamaged and set on top of a massive two-metre deep brick pier.
The sealing of this saddlestone, during mid-late twentieth century conservation, below the tiled surface had weakened the structural integrity of the monument. We were able to deduct that a rotten tenon was encountered at the base of the timber pillar associated with this saddlestone during conservation. This decayed element was then pushed into the socket below and the saddlestone tiled over. During excavation, we also recorded evidence of this practice under other major structural elements, weakening its integrity. Contributing factors in the Kasthamandap’s collapse, these pillars were free-standing, potentially moving at a different rate to the rest of the structure. We have therefore recommended that the traditional design and materials of the monument should be retained as far as possible and that the maintenance of the linking of the foundations to the superstructure is of paramount importance in providing resilience to the entire structure. The removal of modern floor surfaces also revealed the complete layout of the foundations of the Kasthamandap. As anticipated, the bracing cross-walls formed a nine-celled mandala design. Our investigations of the central cell within this mandala, also revealed the presence of a further nine-celled mandala, formed through bracing walls at a lower level, directly below the central sanctum. Adding to the symbolic meaning of the structure, two gold-foil mandalas were found within the northeast saddlestone socket. Meaning that such ritual deposits were discovered at each of the four quarters of the monument, it reaffirms the importance of intangible rituals in the construction of monuments in the Kathmandu Valley.
The further investigations at the Kasthamandap also showed that the foundations throughout the monument were not damaged by seismic activity. Indeed, we have found at other monuments investigated in Hanuman Dhoka that foundations have been strong and resilient, and do not exhibit evidence of seismic damage. Excavations at Jagannath and Gopinath temples, funded by UNESCO, showed that the deep foundations show no earthquake distortion, and preliminary investigations of the brick cores of the stepped plinths of the Maju Dega temple and Jaisedewal, funded by the DoA, are also in good condition. It is therefore likely that the traditional mud mortar and brick architecture of these monuments has led to resilient foundations and that the issues of collapse and damage can be attributed to modern conservation. This includes the use of modern materials such as cement, and also poor maintenance in the replacement of wooden elements within superstructures, and how these are linked to foundations. Excavations in Hanuman Dhoka also identified earlier structures below the brick plinths of the Maju Dega and Trailokya Mohan Temples, confirming the GPR survey results from 2015. These results again stress the importance of multi-disciplinary investigations to provide linkages of expertise between archaeologists, engineers and architects to protect subsurface heritage and provide a holistic view of these monuments, from their foundations below the ground to their architectural superstructures. Such an interdisciplinary perspective will lead to the successful renovation and rehabilitation of these monuments of Outstanding Universal Value within the Kathmandu Valley UNESCO World Heritage Property.
Having uncovered earlier phases of monuments and settlements, which would have been lost without rescue excavations in advance of reconstruction, the events associated with the 2015 earthquakes and aftershocks illustrate the need for capacity building and training in emergency heritage response. Although detailed archaeological rescue excavations are now being conducted in the non-emergency phase, there is a capacity gap in the protection of heritage in the aftermath of an earthquake. Whilst humanitarian efforts are of paramount importance, this is also a critical phase for heritage protection. Therefore, it is imperative that first-responders are trained in the protection of heritage and recovery of historic materials. As a result, we co-organised a live training exercise and workshop within the Pashupati Temple complex to pilot post-disaster heritage recover methodologies. Funded by PADT and AHRC, the training was undertaken at GurujuSattal, a three-storied rest house at the western entrance to the Pashupati Temple complex. Badly damaged in the earthquake, it was subsequently deliberately collapsed. The rubble spread over its foundations provided an ideal opportunity to train first-responders and included participants from the Nepal Police, Armed Police Force and Nepal Army as well as heritage professionals from the DoA, and Officers from the site manager, PADT.
The Guruju Sattal’s ruins allowed us to replicate a collapsed monument, similar to those encountered in a post-earthquake phase but in a safe training environment. It also offered first-responders skills and knowledge of post-disaster archaeological methods and protocols to enable the protection of heritage alongside rapid response during search and rescue efforts. We aimed to develop a simple methodology with three key requirements:
1) a method that could be quickly implemented at, and transferred to, any collapsed monument;
2) a rapid methodology which would not impede the recovery of trapped or injured people within a collapsed monument;
3) a method that could be implemented by non-heritage experts without specialist equipment.
To briefly outline the method, firstly the rubble spread of the monument was gridded, with the reasoning that any rubble removed can be located to a particular area, allowing for the quick removal of material with a robust spatial location. A replicated grid is created near the site, mirroring the layout of the trench, with rubble moved into the corresponding grid square. In the non-emergency phase, when heritage professionals can process the material, it means that artefacts, including structural elements, can be spatially reconstructed in the hope that salvaged material could possibly be reused in reconstruction and conservation. During the exercise equipment to hand to first responders was used, such as mobile phones for photography and shovels for scales and currently an off-line app is being developed to create a forum to deposit site records and a platform for discussions.
Taking a broader perspective, many World Heritage monuments around the globe have been damaged by human conflicts and natural disasters, leading to the creation of emergency preparedness and response protocols as well as the mobilisation of ICOMOS and UNESCO teams. Whilst many aspects of these protocols relate to planned responses, the physical treatment of debris and the use of rescue archaeology to investigate the stability of foundations in such situations are less well defined. Whilst a human and cultural catastrophe, multi-disciplinary investigations of Kathmandu’s post-disaster environment has the potential to offer invaluable training for professionals in the scientific documentation and recording of in-situ debris, archaeological risk mapping and structural subsurface foundation recording in advance of reconstruction and rehabilitation. The resultant exemplars, supported by research into traditional construction technologies and the reuse of materials, provide the potential to offer robust methodologies and techniques to those tasked with subsequent research, rehabilitation and rebuilding of damaged heritage, particularly in the Middle East.
- Coningham, R.A.E., Acharya, K.P., Davis, C.E., Kunwar, R.B., Simpson, I.A., Schmidt, A. & Tremblay, J.C. (2016). Preliminary Results of Post-Disaster Archaeological Investigations at the Kasthamandap and within Hanuman Dhoka, Kathmandu Valley UNESCO World Heritage Property (Nepal). Ancient Nepal 191-192: 28-51.
- Coningham, R.A.E., Acharya, K.P., Davis, C.E., Kunwar, R.B., Tremblay, J.C., Simpson, I.A. & Schmidt, A. (2016). Preliminary Results of Post-Disaster Archaeological Investigations at the Char Narayan Temple and within Patan’s Durbar Square, Kathmandu Valley UNESCO World Heritage Property (Nepal). Ancient Nepal 191-192: 52-71.
- Coningham, R.A.E., Acharya, K.P., Davis, C.E., Kunwar, R.B., Tremblay, J.C., Schmidt, A. & Simpson, I. (2016). Preliminary Results of Post-Disaster Archaeological Investigations at the Vatsala Temple and within Bhaktapur’s Durbar Square, Kathmandu Valley UNESCO World Heritage Property (Nepal). Ancient Nepal 191-192: 3-27.
- Coningham, R.A.E., Acharya, K.P., Davis, C.E., Kunwar, R.B., Tremblay, J.C., Schmidt, A., Simpson, I. & LaFortune-Bernard, A. (2016). Post-Disaster Rescue Archaeological Investigations, Evaluations and Interpretations in the Kathmandu Valley World Heritage Property (Nepal): Observations and Recommendations from a UNESCO mission in 2015. Ancient Nepal 191-192: 72-92.
From the Department of Archaeology
- UNESCO Professor Robin Coningham
- Dr Christopher Davis
- Dr Mark Manuel