Claim Missing Document
Check
Articles

Found 2 Documents
Search
Journal : Jurnal Geologi dan Sumberdaya Mineral (Journal of Geology and Mineral Resources)

LANDSLIDE HAZARD ASSESMENT ON JAVA ISLAND Case Study: Landslides In Warungkiara, Bogor, Majalengka, Banjarnegara And Jember Utomo, Edi Prasetyo
Jurnal Geologi dan Sumberdaya Mineral Vol 23, No 1 (2013): Jurnal Sumber Daya Geologi
Publisher : Pusat Survei Geologi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (762.87 KB)

Abstract

All of landslides recorded in Indonesia between 2003 – 2006, 90% of the events occurred on Java Island, Indonesia. Due to lack of long term statistical data, their characteristics are not well known. Based on the analysis of climate, geology, topography and landslide statistical data, the landslide characteristics on Java Island can be ascertained. It can be concluded that the frequency of occurrences of landslides are highest in the southern part of the West Java Province, followed by the Central Java Province and the East Java Province.Landslides on Java island can be classified based on their triggering factors, which comprise: rainfall, morphology, earthquakes, lithology, and the occurrence of active faults. As far as types of landslides are concerned, rockslides and toppling are rather rare, while most landslides are of the sliding (translation, rotation, block failure), creeping and debris flow types. The materials involved in landslides comprise weathered volcanic breccia, sedimentary material mixed with clay, mudstone, sandstone, limestone, marl and pyroclastic (deposits of volcanic ash and tuffaceous sand) and loam.Landslide events significantly occur in the rainy season, especially from December to April. Dead and missing victims by landslides increase when annual rainfall is in excess of 2100 mm. In this paper, with reference to the above mentioned factors and conditions, type of landslide prone areas and countermeasures will be discussed.Keywords: Landslide hazard, Java Island, classification, statistical data analysis.
Changes in the Configuration of the Fresh Water Lens due to ASRRG, Western Part of the Tiny Pari Island, Seribu Islands, Jakarta, Indonesia Utomo, Edi Prasetyo; Purwoaminta, Ananta; Sudrajat, Yayat
Jurnal Geologi dan Sumberdaya Mineral Vol 18, No 1 (2017): Jurnal Geologi dan Sumberdaya Mineral
Publisher : Pusat Survei Geologi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (465.671 KB)

Abstract

Pari Island (Pulau Pari) is a small coral island in the Seribu Islands group off the north coast of the Jakarta Capital Special Region. Government has planned to develop this island into a tourist attraction because of its beautiful environment. However, the government development plans have not included facilities to meet the demand for groundwater, which represents the principal resource to meet the demand for freshwater. Pari Island has limited resources of groundwater due to the small size of the area where recharge of groundwater from rainfall can take place. A problem will arise that with the increase of visitors to the island the demand for freshwater will increase, while  groundwater resources of the island are very limited and dominated by brackish and saline groundwater. The objective of this research was to explore the possibility to increase the resources of fresh groundwater of Pari Island to support the increasing demand of fresh water. The method employed in the research is the application of ASRRG technology by the injection of the largest possible volume of rainwater and monitor changes of electrical conductivity and geoelectrical resistivity. Installation of an ASRRG network proved effective in lowering the salinity of groundwater in small islands. By increasing pore volume from 30% to 60% salinity decreases by 77%, which is reflected by the effect that the fresh groundwater lens which before comprised brackish water became fresh water with a thickness of 2.5 meter. The gain in pore volume equaled the decrease in salinity.Key words: Artificial recharge, Island hydrology, Salt-water/fresh-water relations, Indonesia