Gunung Merapi Research Articles

Insights into the October–November 2010 Gunung Merapi eruption (Central Java, Indonesia) from the stratigraphy, volume and characteristics of its pyroclastic deposits

The 2010 eruption of Merapi was the second most deadly in the historic record of this volcano, claiming over 380 lives. By relating the observations of this eruption with detailed examination of deposit distribution, stratigraphy and sedimentology, a reconstruction of the properties of the pyroclastic density currents (PDCs) is presented, including the valley controlled block-and-ash flows (BAFs) and widespread, energetic pyroclastic surges. The distribution, volume and mobility characteristics of all types of PDC during the eruption sequence show evidence for levels of intensity unseen since the large-scale 1872 and 1930 eruption phases, especially during the climactic events of October 26 and November 5. Many tephra falls interbedded with PDC units show that most dome-collapse events occurred along with and between explosive vulcanian eruptions. The 2010 eruption produced very long-runout BAFs, reaching 16.1km in the Kali Gendol on November 5. This runout could be explained by its large-volume (20millionm3), around 10 times that of previous Merapi BAFs during the last 130years. Major avulsion of these dense BAFs to form overbank deposits became more common through the eruptive sequence as the valley was progressively filled with successive PDC deposits. Spreading avulsed BAFs were a particular hazard downstream of ~10km where the landscape is less dissected. Less clear, however, is why pyroclastic surges extended up to 10km from the vent on November 5 and >6.4km on October 26. These expanded much farther from BAF margins (~2km) than ever seen before at Merapi. In one location they were decoupled from valley-centered BAFs with high momentum, traveling initially laterally across steep valley systems, before draining downslope. At this site, on the western side of the upper Gendol at around 3km from source, surge decoupling was apparently exacerbated by upstream collision and deflection of high-flux, hot and gas-rich BAFs against the cliffs of Gunung Kendil. The 1.4km-long cliff face was impacted directly for the first time in 2010 events, and may have been responsible for the formation of larger than normal turbulent ash-rich clouds above BAFs. These results imply that future eruption events under the present summit and upper flow-path configuration are also highly likely to generate wide dispersal pyroclastic surges and extreme hazard, especially now that dense forest has been destroyed on the upper southern slopes of the volcano.

KONSERVASI SUMBERDAYA ALAM DI TAMAN NASIONAL GUNUNG MERAPI: ANALISIS EKOLOGI POLITIK

Gunung Merapi is one of the mountain ecosystem in the center of Java island. The ecosystem is located under the administration of Yogyakarta Special Province and Center of Java Province. Since May 4 th , 2004, the ecosystem has been appointed as Gunung Merapi National Park under the decree of Minister of Forestry Number 134/2004. Polemic over the appointment has been emerged before the decree issued and still continuing after. This research has been conducted in 1) Ngargomulyo village, Dukun, Magelang, Center of Java Province, 2) Jurangjero sand mining area in Ngargosoka, Srumbung, Magelang, Center of Java Province and 3) Kaliurang tourism destination area in Hargobinangun, Pakem, Sleman, Yogyakarta Special Province on Juli 2005 and Juni-Juli 2006. This research aimed to 1) mapping natural resources right and access mechanism and 2) analyse conflict between Environmental Non-Government Organisations (ENGOs) and Government. Using political ecology analysis, the research shows that the appointment of Gunung Merapi National Park only benefiting them living in tourism destination and sand mining area, but giving uncertainty for them living in village as a farmer. The research also identified that the conflict between government and ENGOs is the conflict of conservation discourses. The strategy for the future development of Gunung Merapi National Park is suggested as follows: 1) government should understand the natural resource access mechanism which has been worked in the Merapi ecosystem and 2) government should work together with the grassroots organisation to implement policy in the field level and with the ENGOs to develop natural resources conservation discourses. Key words: national park, access, conflict, political ecology, conservation discourses

Exploring the Potential of Silviculture Agroforestry Regime as a Compatible Management in Southern Gunung Merapi National Park, Java, Indonesia

Silviculture Agroforestry Regime (SAR) is a compatible management model between the local community agroforestry with the intensive buffer zone and Gunung Merapi National Park (GMNP) through forest rehabilitation and renewal zonation system. The aims of this study: to assess the prospects of SAR among the stakeholders, i.e. the local community, the government and the researchers, as well as the challenges on its implementation. This study employed the SWOT analysis (i.e. strengths, weaknesses, opportunities and threats), synergized with the Analysis of Hierarchy Process (AHP) approach to quantitative the potential of SAR. The results revealed that SAR has a high potential for implementation in GMNP as a compatible management approach. In accordance with the stakeholders’ perception, the strengths and opportunities outweigh the model’s weaknesses and threats. SAR is potential for encouraging prospective buffer zone with intensive agroforestry management and also for accelerating forest rehabilitation and renewal zoning system of GMNP. Nonetheless, the implementation of SAR must be integrated with various strategies, for instance, the capacity building, documentation process and outcome, participative monitoring and evaluation, back up policy, experimental plot, compensation programme and skill improvement of silviculture agroforestry. Hence, SAR is serving as a “window opportunity” for learning model that includes the reference outside the national park as a promising buffer zone for developing this new Indonesia’s national park, which avoids the image of ‘paper park’.

Silviculture Agroforestry Regime: Compatible Management in Southern Gunung Merapi National Park, Java, Indonesia

Silviculture agroforestry regime (SAR), which is a compatible management with forest rehabilitation and alsorenewal zoning system of the national park, was started to increase the agroforestry productivity surroundingGunung Merapi National Park (GMNP). In addition, SAR also supported the basic information succession ofMount Merapi eruption in 2006 to strengthen Merapi lava tour. This is an innovative step in developing GMNP,in which its pro-poor conservation is not only based on land productivity, but also based tourism. This study wasbegun with the development of a permanent plot to study succession (May 2008-Novemper 2009), and theimpact of community intervention on grass stock at GMNP, as well as to assess agroforestry typology and itsimplication on the areas surrounding GMNP. SAR was developed using landuse model based on limiting thefactor of each agroforestry cluster. Choosing the treatment in SAR refers to the actual condition and opportunityevery agroforestry cluster and sensitivity analysed until the intervention on the GMNP was minimal. Theimplementation of SAR was done with a software known as Stella 9.0. There are five SAR models which areappropriate for agroforestry cluster (AF); these are labelled as AF1-SAR1, AF2-SAR2, AF3-SAR3, AF4-SAR4and AF5-SAR5. SAR is based on resources sharing whereby space is arranged through crown pruning and alsorationalization number of dairy cows. In addition, SAR has a packet management for synergizing function ofprivate lands (homegarden, dry field and land village as a unit management) and intensification by land tillage,renewal of grass and fertilization. In particular, SAR1-5 has the ability to balance agroforestry management withdecreasing local community intervention and increasing biodiversity level on GMNP. The ratio for grassproductivity outside GMNP with grass necessity and implementation of SAR was close to an optimum point (1).Meanwhile, the ratio values of SAR1-5 were 0.982, 1.010, 1.44, 1.047 and 1.253, respectively. Nonetheless, theimplementation of SAR needs more technology of silviculture agroforestry and a full support from stakeholders.

The Dynamic Growth and Standing Stock of Acacia Decurrens Following the 2006 Eruption in Gunung Merapi National Park, Java, Indonesia

Following the 2006 eruption in Mount Merapi, Indonesia, it is important to assess the dynamic growth and potential standing stock of Acacia decurrens as a woodfuel for the local community surrounding in the southern of Gunung Merapi National Park. Five plots (P1, P2, P3, P4 and P5), were established. This study carried out in May 2008. During the period of 18 months, the performance of A.decurrens was examined: recruitment, mortality, survival, diameter, height, density, basal area, volume and relative rate change. The highest average diameter and height of A.decurrens were 14.22±1.85cm and 5.97±0.66m, respectively. Standing stock was based on the highest average of the basal area (i.e. 72.067±18.51 m2/ha) and volume (i.e. 184.44±24.59 m3/ha). The results of this study were important information in supporting the Merapi lava tour and the standing stock of A. decurrens, which promises the local community with a schematic compatible management for GMNP.

SO<sub>2</sub> EMISSION MEASUREMENT BY DOAS (DIFFERENTIAL OPTICAL ABSORPTION SPECTROSCOPY) AND COSPEC (CORRELATION SPECTROSCOPY) AT MERAPI VOLCANO (INDONESIA)

The SO2 is one of the volcanic gases that can use as indicator of volcano activity. Commonly, SO2 emission is measured by COSPEC (Correlation Spectroscopy). This equipment has several disadvantages; such as heavy, big in size, difficulty in finding spare part, and expensive. DOAS (Differential Optical Absorption Spectroscopy) is a new method for SO2 emission measurement that has advantages compares to the COSPEC. Recently, this method has been developed. The SO2 gas emission measurement of Gunung Merapi by DOAS has been carried out at Kaliadem, and also by COSPEC method as comparation. The differences of the measurement result of both methods are not significant. However, the differences of minimum and maximum result of DOAS method are smaller than that of the COSPEC. It has range between 51 ton/day and 87 ton/day for DOAS and 87 ton/day and 201 ton/day for COSPEC. The measurement of SO2 gas emission evaluated with the seismicity data especially the rockfall showed the presence of the positive correlation. It may cause the gas pressure in the subsurface influencing instability of 2006 eruption lava. Keywords: SO2 gas, Merapi, DOAS, COSPEC

VALUATION OF MOUNT MERAPI NATIONAL PARK: A TRAVEL COST ANALYSIS

This study estimates recreational value of Taman Nasional Gunung Merapi (TNGM – Mount Merapi National Park) in Kaliurang, Yogyakarta with a travel cost method. Since the visitors are not the frequent ones, the paper estimates the visitor’s utility using a categorical regression technique. Applying in-depth interview on visitors from August 1st until August 15th 2009, the results suggest that the utility function for recreation at volcano national park is better estimated using the negative binomial distribution model. It also finds that the economic value of recreation at volcano national park is Rp 222,000, and that the total consumer surplus for recreation national park is Rp 31.2 billion. Keywords: Travel cost valuation, binomial regression model, recreation national park valuation JEL classification numbers: D12, L83

Aggressive behavior of macaques, Macaca fascicularis (Raffles, 1821) on tourists at Kaliurang nature recreation forest, Yogyakarta

Research was conducted in Kaliurang nature recreation forest area, in Gunung Merapi National Park, Yogyakarta. The research aim to investigate the proportion of aggressive behavior of monkeys [Macaca fascicularis (Raffles, 1821)] to tourists. Direct observation method was used to observe the monkeys behavior in the interaction to the tourists. And questioners were distributed to the tourists to know expectation of the tourists which related to the existence of the monkeys in that conservation area. Analyses of the interactions suggest thatmonkeys respond differentially to tourists according to the age/sex classes involved. Additionally, adult and subadult male monkeys participated in more aggressive behaviors than expected, while adult female monkeys and immature participated in such behaviors less than expected. These variations in interaction patterns between monkeys and tourists may have substantial implications for management issues and that the potential for gaining or reducing the tourists to visit in that forest recreation.Key words: monkey, Macaca fascicularis (Raffles, 1821), tourists, aggression; tourists-monkeys interactions.

PENGGUNAAN LEGAL STANDING ORGANISASI LINGKUNGAN HIDUP DALAM RANGKA PENEGAKAN HUKUM LINGKUNGAN

The research results show that the implementation of the WALHI legal standing is only implemented in two cases. They are Taman Nasional Gunung Merapi and PT. Griya Perwita Asri case. The efforts of the law enforcement that have been conducted by WALHI tend to the advocacy and the awareness of the community rights toward environmental. Meanwhile, the obstacles which are faced by WALHI in implementing its legal standing are WALHI is tends to do the awareness of the community rights and advocacy than legal standing, because it is most appropriate target; the law officers are lack response to the legal standing case; the regulation is not clear yet; and the lack of the human resources. Although the implementation of the WALHI legal standing is not effective yet, but their roles in criticizing the Government policy have been giving a lot of changes through the pressures that have been done.

THE ENVIRONMENTAL IMPACT OF NATURE BASED TOURISM IN GUNUNG MERAPI NATIONAL PARK

The goal of this research is to find out some impacts of tourism activities to the environmental mainly to the biotic and non-biotic components. The research also focuses in finding out importance and performance of the products offered-by Gunung Merapi National Park to the tourists. This research is done in four locations, consisted of the undisturbed location for controlling (Plawangan) and the disturbed locations caused by the tourists, which are Kalikuning, Tlogonirmolo and Tlogomuncar. The result shows that the impClcts of tourist activities in some locations show that the number of .microbial in the controlling location-is the highest (54.56 cfu/gram) compared with others location. The impact to the number of actin0mycetes in the controlling location is 32.84 cfu/gram, which is the highest. The infiltration rate with the model Horton in the controlling location is higher (0.983 cm/min) than the infiltration rates of the others. The voice frequency describes crowd level that at the controlling location has the lowest voice frequency (10.15 dB). Some kinds of tree destruction as the impact of tourist activities show that the destructions happen mostly in Tlogomuncar, followed with Kalikuning and Tlogonirmo 10. The most severe destruction of all locations is vandalism, and then scratch, spike prickling, branch breaking, and waste burning. Ihe importance and .performance of the products of the tourism objects offered describe that the attractions and tourism facilities like waterfall, musholla, shelter, dustbin, and observer tower have a considerable perception and good performance. However, some other facilities/attractions such as operational office, security center, gate, health clinique and bridge are not very important and not in a good condition.

Monitoring ground deformation at the decade volcano Gunung Merapi, Indonesia

Pressure changes within a volcano lead to deformations of his edifice. To discriminate local and regional ground movements, four deformation stations with clusters of continuous borehole tiltmeters have been installed at the hillsides of Gunung Merapi. In addition, recording local environmental parameters allows the recognition of interfering local tilt signals. First analyses of the data records show: The significant tidal variations of the tilt signal validate the successful coupling between the instruments and their surroundings. Transient tilt signals correlated to rainfalls are probably caused by poroelastic deformation of the hillsides. Four volcanic events occurred during the observation period; all of them were accompanied, if not triggered, by heavy rainfalls. Tilt anomalies, considerably larger than the rain induced tilts, were recorded around the event of October 31, 1996, coincident with an extraordinary high seismic activity. If this activity reflects internal fracture processes prior to the eruption, the accompanying deformations might partially explain the observed tilt signal.

Effects of Earthquake in Sumatra

ON May 17, 1892, an unusually severe earthquake was felt through nearly the whole of North Sumatra; most severely shaken was the district between the Dolok Lubuk Raja and the Gunung Talamau (Ophir). Serious landslips occurred in many parts of the mountains, especially near the summit and along the slopes of the Gunung Merapi, a volcano 2145 metres high in the residency Tapanuli. On inspection it was found that the safety of a brick pillar, erected on its most elevated point by the triangulation service, was endangered by part of the crater having been destroyed. At three metres distant from the original pillar, as much as the narrow ridge would allow, a new pillar was built, the top of which was made level with that of the original one. The measurements made in order to fix the position of this new pillar showed such differences with the original measurements, that these could only be explained by a displacement of the original pillar. As, however, neither fissures nor local disturbances of the ground could be observed, new measurements were made from all the surrounding positions, and it was proved that a displacement of several more pillars had taken place.