Conservation and enhancement of earthen architecture in archaeological sites of the Nile Valley – NilesEarth

The Nile's Earth project was conducted using a combination of research methods. It included:

. Identification of existing littérature and extraction of key issues

. Field missions with various objectives ranging from visual observation to participation in excavations (to address identification issues), environmental observations (geomorphology), interviews with stakeholders, and finally, hands-on works.

. Testing of the collected materials, including, where possible, laboratory tests, allowing for comparative analyses between the two types of practice.

. The design and implementation of conservation works with varying degrees of innovation, primarily with a preventive approach.

With a view to initiating a more global debate on the topic, several seminars and a major international conference were organized.

Finally, with a view to disseminating the results, special efforts were made in publication and training. In addition to formal activities, each project initiative also provided an opportunity for exchanges and knowledge transfer between local and international experts.

Nearly 30 field missions were organized, which enabled the following:

• Completion and refinement of the existing documentation on earthen structures, including, for Plinthine site, the preparation of a catalog of construction methods.

• Development of a documentation protocol, including for sampling materials for laboratory analysis.

• Conducting field surveys (primarily in Sudan) to establish the relationship between ancient construction techniques and those still in use.

• Assessment of the state of conservation of the sites (or updates: Sai, Karnak) and identification of the circumstances and processes of degradation at a variety of sites, as well as threats and risks, identification of common aspects and specific features (climates, water table levels and salts presence).

• Implementation of conservation works at four sites (Kerma, Medamoud, Treasury of Chabaka, Pepy I) by incorporating innovations, then observing their behavior and drawing initial conclusions. This enabled the identification of avenues for future researches and experimentations.

A large number of literature reviews were conducted, leading to the recognition of the difficulty of synthesizing them. However, some of these studies, linked to the organization of two seminars, resulted in an original publication on Storage Buildings.

Regarding the study of materials, after sharing a variety of protocols and testing options, analysis were conducted, enabling progress on material characterization, soil selection, and for some of the tests on how to undertake them properly. Progress was also made in comparing field and laboratory tests, which have been and will continue to be the subject of scientific articles.

With regard to geomorphological studies in particular, a better understanding of the relationships between societies and the environment (society and rivers) has been initiated, opening up new avenues of research.

The major outcome of our project is the Nile's Earth 2023 conference, with 130 participants from 18 countries discussing 32 papers (three themes). This conference resulted in a declaration, and it is planned to be held again in Egypt in 2027.

Finally, the training efforts resulted in two specific actions: the training of 5 professionals in Grenoble for 2.5 months and the preparation of dematerialized courses (5) adapted to the Sudanese context made available to the SFDAS.

Despite difficulties encountered and some results that do not reach all initial expectations, the impact of the Nile's Earth project appears to be real, and the prospects are numerous, at various levels and with timescales that, more specifically for Sudan, depend heavily on the security situation.

In the short term (within six months after project's completion), the following are planned:

• Exploitation of the acquired data through the writing of numerous scientific articles

• Completion of a PhD thesis (C. Venton) supervised by Hisoma, which will continue the work undertaken at Plinthine and Taposiris and expand it to seven other Egyptian sites;

• Continuing studies on various structures at the Karnak site (enclosing walls, chapels, etc.)

• Integrating data related to Sudan's contemporary earthen architectural heritage as part of the SFDAS project entitled IMAHP (Innovative Monitoring Approaches for Heritage Protection in Sudan), funded by the Ministry of Foreign Affairs and Foreign Affairs and the ALIPH Foundation;

In the medium term (1 to 2 years):

• Continuation of conservation work at Medamoud and at the Pepy I necropolis

• Continuation of research on conservation issues, particularly those related to the problem of plant proliferation (focus on alpha) and for sites affected by salt concentrations

• Training on the conservation of earthen archaeological heritage is also being developed (funding obtained from the Ministry of Foreign Affairs and International Development (MEAE) with co-funding from the CNRS to be confirmed).

• At Plinthine and Taposiris, cross-referencing of data (maps from remote sensing of earthen sources, geomorphological data, and the results of brick composition analyses) to attempt to locate ancient earth quarries, according to the periods.

Longer term (2 to 5 years)

• Preparation of applications for the organization of training courses for the MoTA, potentially organized in Karnak with the support of the CFTEEK

• The CFTEEK could lead or participate in the organization of a new conference in Luxor on the study and preservation of mudbrick constructions. Possible date: 2027 (CFTEEK's 60th anniversary).

• Reuse of methodologies in other contexts with similar climates (e.g., Central Asia).

As soon as the situation in Sudan improves: resumption of excavations at Kerma with in parallel, continuation of studies on vernacular architecture and geomorphological explorations in order to improve the understanding of the spatial organization of the site, the relationships between human settlements, sedimentary deposits and the movement of the watercourse.

Since the birth of Egyptology in the 19th century and of Sudanology later on, scholars working on ancient Nile valley societies have mainly focused their interests on the stone buildings. In contrast, the study of mud-brick architecture has mostly been limited to its most monumental (e.g., enclosure walls) or complex (vaults and domes) manifestations. As a consequence, conservation efforts are almost exclusively dedicated to preserving stone architecture.
However, earth – the most common building material in Egypt and Sudan from the earliest times to the present day – has been the subject of much renewed interest in recent years. Besides, Egyptian and Sudanese authorities increasingly require specific actions for the preservation of this important cultural heritage and to present it to the public.
This has led to first conservation attempts. However, these consolidation works, frequently linked to partial reconstructions, are often questionable both in terms of durability and authenticity. Archaeologists and conservators face several problems. First, during excavation, the structures must be properly identified and their fabric and building techniques correctly characterised. Second, just after excavation, these revealed yet fragile remains must be preserved from exposure to the elements. Finally, it is necessary to ensure the visibility of the remains and the proper understanding of their nature and historical value.
This project aims at formulating relevant solutions to respond to the growing demand for the proper conservation and valorisation of earthen architecture found at archaeological sites along the Nile Valley. Therefore it will propose both additional interventions during and just after excavation, as well as long-term actions for the conservation and presentation to the public. New methodologies and practices will be developed from on-sites experimentation, including identification and characterisation; condition survey protocols; restoration techniques; preventive conservation during excavation; regular maintenance; and site management.
This project gathers a team of experts from complementary fields: Egyptologists, architects, archaeologists, archaeobotanists, geomorphologists, conservators, and physicists. The project will exploit the potential of knowledge provided by architectural studies and archaeology along with geomorphological studies, geotechnical, archaeometric, and archaeobotanical analyses conducted on soil and brick samples from several sites in Egypt and Sudan. These are well distributed across the area under consideration and are representative of its different environments (desert, valley, Egyptian fringes, Mediterranean coast). This multidisciplinary approach will allow the accruement of knowledge on the variety of materials and the different construction techniques used.
The study of recent conservation attempts, which has led to the development of this project, will be further deepened, with additional field visits and an in-situ testing programme. Results from recent earth architecture conservation research conducted at archaeological sites in the Arabian Peninsula, Iran, and Central-Asia will also be integrated in the project.
An international conference will be organised at the halfway point (2023). The scientific results of the project will be published in two volumes: one on earthen architecture and building techniques, the second on methodological approach and techniques for the long-term conservation of this outstanding heritage. The ultimate ambition is that these publications will long last as a reference in the field.