Monitoring of the Borobudur Post Restoration (Presented Paper at 21st Conference on International Cooperation in Conservation, Tokyo 3-7 Dec 2007)

1. INTRODUCTION
Candi Borobudur is the outstanding temple in Indonesia. Located on the Borobudur plain, this temple sits majestically in an open area about forty kilometers from Yogyakarta. It was built around 824 CE by Samaratungga, king of the Syailendra dynasty a flourishing Buddhist kingdom.
Borobudur building finished about 125 years after construction begun, and utilize by religious activities until 11th century. About two century after construction Borobudur wasn’t used by people because of the great disaster in Java Island, and also because of the civilization movement to East Java. Borobudur became forgotten until opened by Raffless at 1814, and than completely cleaned by Hartmann from Dutch Indies Government at 1835.
Borobudur has been restored twice, the first restoration of Borobudur done by Theodore van Erp at 1907-1911 and the second restoration done by Indonesian Government and UNESCO at 1973-1983. Today, it is a UNESCO World Heritage Site in 1991 (number 592) and one of the largest Buddhist temples in south-east Asia.


2. RESTORATION OF BOROBUDUR
The first restoration of Borobudur was conducted by Theodore van Erp. This restoration mission is to reconstruct the temple completely by repairing the area of stupas and foot building. The body of the temple (main wall and balustrade) doesn’t dismantle. Some of the main wall still sloping and the floor made flat by stone blocks layer and mortar. This restoration can return successfully the whole structure of Borobudur Temple.
The main problem of the temple after first restoration is the water penetration. At rainy season the soil beneath the temple become completely wet and produce unstable condition to the wall. The wall-slope increased because sink into the ground and became danger. The water also flows through the stone joint of the wall, and accelerate the deterioration both in chemical and biological.
Indonesian Government with UNESCO cooperates with restore Borobudur in 1973-1983. This second restoration focused on reconstruction of the wall and floor. Concrete slabs structure placed under the wall and floor to maintain the stability of the wall. The sculpture gallery on the wall isolate from the water penetration by waterproof layer behind the wall stone blocks. The concrete slabs under the floor used as drainage system to collect the rain water before pass the drainage pipe.
The structural stability problems of the Borobudur temple already finished after the second restoration. The structural stability continuously monitored to control the temple deformation horizontally and vertically as well.

3. CONSERVATION PROBLEM AFTER RESTORATION
The main problem in Borobudur temple after restoration is the deterioration rate. Borobudur placed in open air environment and affected directly by sun rays, rain water, and air continuously. This condition accelerates the deterioration of the stone. The sun exposure and water will support the biological growth. First, the growth of microbiological such as bacteria, algae, and fungi occur. These organisms grow by takes mineral compounds of the stone as medium. After the growth of microbial, the other organism such as moss and lichens grow. The higher organism like ptheurodophyte and spermatophyte grow than on the stone joint.
The stone mineral structure will be degradable because of the activity of the organism that takes mineral compound and secrete organic acid. The organic acid will solubilize some cations of the stone mineral. Controlling microbiological growth became one of the main activities of conservation in Borobudur.
Other conservation problem of Borobudur temple is the chemical deterioration. Chemical deterioration naturally happened for all type of material, because deterioration reaction is natural phenomena. The problem is when the high rate of deterioration happening. In Borobudur temple the main problem of chemical deterioration is the efflorescent/scaling. Water moving in the stone-pores solubilizes the salt compound. The salt may soluble before water penetrate the stone or from the part of stone compound. After water containing salt reach the surface, water will be evaporates because of sun exposure and wind, and produce salt deposit on the surface.
Salt deposit stop the stone pores and produce further deterioration. Surface of the stone became erodes because of the stress from water inside the stone pore, and some times microbial activities promote this alteration. Salt deposit also formed on the stone joint, and we call cementation. Cementation will join the stone blocks each other and decrease the stability of the monument from mechanical movement. Physical properties of salt deposit very hard and difficult to remove from the surface. The monitoring of salt population and efflorescent important to done, in order to understand the process and stop its formation.

4. MONITORING OF DETERIORATION
The monitoring problem of Borobudur temple is the large size of the building. The length of each side is 121 meter, and the height of the whole building 35.40 meter. Consist of three part of building. The temple-foot as the part of the lowest building construct by two level of foot structure. The body of the temple, consist four levels of main wall and five levels of balustrades with the sculpture gallery (bas-relief). Totally amount panels of bas-relief are 1460 panels. The upper of the building consist of three level terraces with 72 small stupas, and one main stupa at the center. The deterioration monitoring focused on the main wall and balustrade with the bas-relief.
a. Microbiological Growth
The type of microbiological grow on the temple are moss, lichens, and algae. These organisms grow influence to the climate condition. As a country in tropical region, Indonesia has two seasons (rainy and dry season). At rainy season the growth become very quickly, and decreased when dry season enter. At the end of dry season the organism dry and die.
The monitoring of microbiological done at rainy season, while the highest grow of the organisms. In this condition the conservation work are cleaning by mechanical (manual) and water. The monitoring data used for the conservation work to doing the treatment with bio controlling chemicals. The chemicals apply before next rainy season to prevent the growth. According to the monitoring data, conservator applied the chemicals on the temple. Monitoring data also used for the evaluation of the conservation effectiveness.
b. Chemical Deterioration
Chemicals deterioration monitored in Borobudur are efflorescent, salt deposit (scaling), cementation, postule, and alveoli. Efflorescense, scaling, and cementation formed at the same process. The monitoring data used for conservation work for cleaning, both in chemical and mechanical. The location and population of the deterioration from the monitoring used by conservator to conducted the cleaning. Monitoring of alveoli and postule use by conservator to identified the location to be treated.
The whole monitoring of chemical deterioration used to understand the process and minimize the population growth. These chemical deteriorations are still problems to be solved in Borobudur temple.
c. Physical Deterioration
Monitoring of physical deterioration consist of fissuring, erosion, and other physical damages. Monitoring data of fissuring used by conservator to identify the location to be restored. The erosion and other physical damages correlated to the chemical deterioration.
Monitoring of the physical deterioration used to understand the other damages. Fissuring data used to control the stability of the building and stone formation. In the fissuring case, after join the crack, stability of stone formation checked and stabilized by wedging.

5. METHODOLOGY OF DETERIORATION MONITORING
The objective of the monitoring is to quantify the population of each deterioration parameter. The monitoring data used as basic guide of the conservation system, and to describe the deterioration factor and its process. The methodology of the monitoring is by mapping the whole relief. Each parameter done at different time or schedule with different map. The technical drawing used as basic map that represent the formation of the stone blocks. The map printed on the white paper and the result of the observation wrote on it.

6. NEW DEVELOPMENT METHODOLOGY OF MONITORING
The monitoring by mapping can describe the deterioration condition of the stone and useful for conservation work. However the mapping by direct observation difficult to quantified exactly the percentage of the deterioration. The percentage of deterioration area on the stone block calculates by estimation of the observatory. This observation data was sufficient for basic information for the conservation work only. The more exact quantify monitoring system needed for the scientific evaluation of the deterioration change.
The new monitoring methodology develop by modify the direct observation with digital drawing. This methodology suggested by Mr. Costantino Meucci Expert from UNESCO since last two years. The main objective of the UNESCO Expert mission is to understand well the deterioration phenomena of Borobudur especially in the rate of effloresce and scaling. For this purpose we need precise and accurate data of the monitoring for all deterioration type. Because of the large area of the temple, this monitoring done on 16 panels of relief as samples. These panels observed every two month to monitor the deterioration change.
The outline of the monitoring method describe as following:
a. Photograph the panels
b. Import the picture to AutoCAD program and fit the dimention picture with original
c. Field observation to compare the original and picture.
Those photos are printed as needed to be used for survey related to the stone condition in the field, according to the parameter made. The result of the field survey is used for conducting photo digitalization that has been transferred to AutoCAD.
d. Digitalize the area of each deterioration on AutoCAD
Digitalization is conducted by the personnel taking part in conducting the survey in the field to avoid the mistake in processing data. Digitalization lines are made in various colours to differentiate the parameter one to another.
e. Quantify the area on AutoCAD
The volume of each parameter is automatically calculated by using AutoCAD menu then the result of the digitalization is used as the standard of comparison to the observation period, before and after.

7. CONCLUTION
Monitoring is one of the most important activities in conservation after the cultural properties restored. The monitoring useful to control and maintain the restoration system works. And also to understand the whole deterioration and damages that still happen on cultural properties, in order to control its rate. The monitoring data also directly used by conservation worker to identified the location to be conducted the intervention.

8. REREFENCE
Cahyandaru, Kasiyati, Sulihanto, (2007), Evaluation of Monitoring and Repairing Borobudur Temple Related to the Stone Degradation by Seepage Water, Borobudur Heritage Conservation Office
Jutono & Hartadi. S, (1973), Report on the Biodeterioration Processes of Borobudur Stones, Pelita Borobudur, Seri.B No.2
Kumar & Kumar, (1999), Biodeterioration of Stone in Trapical Environtment, the Getty Conservation Institute, USA
Meucci. C, (2007), Degradation and Conservation of the Stone, Candi Borobudur Research Program, Rome
Monitoring Team of BHCI (2006-2007), Monitoring of Deterioration on Borobudur Panels Sample and Traditional Mortar Application, Bimonthly Report from Borobudur Heritage Conservation Office to UNESCO
Parkani, (1999), Archaeological Chemistry, Bradshaw & Co, London
Price. C A, (1996), Stone Conservation; an Overview of Current Research, the Getty Conservation Institute, USA
Stambolov. T, van Asperen de Boer. J.R.J, (1976), The Deterioration and Conservation of Porous Building Materials in Monuments, International Center for the Study of The Preservation and the Restoration of Cultural Property, Rome
Torraca. G, (1982), Porous Building Material – Material Science for Architectural Conservation, ICCROM, Italy