Hasanuddin Z. Abidin

Adaptation and mitigation of land subsidence in Semarang

Land subsidence is not a new phenomenon for Semarang. Some report said the subsidence in Semarang probably is occurring for more than 100 years. Based on the leveling surveys conducted by the Centre of Environmental Geology from 1999 to 2003 it was found that relatively large subsidence was detected around Semarang Harbor, Pondok Hasanuddin, Bandar Harjo and around Semarang Tawang Railway station, with the rates ranging from 1 to 17 cm/year. Results derived from GPS show that land subsidence in Semarang has spatial and temporal variations. In general, subsidence rates in Semarang have an average rate of about 6 to 7 cm/year, with maximum rates that can go up to 14-19 cm/year at certain locations. The impact of land subsidence in Semarang can be seen in several forms, such as the wider expansion of (coastal) flooding areas “rob”, cracking of buildings and infrastructure, and increased inland sea water intrusion. It also badly influences the quality and amenity of the living environment and life (e.g. health and sanitation condition) in the affected areas. In the case of Semarang, adaptation and mitigation are considered very important. We have been done some investigations to this area by field observations (mapping the flooded area, mapping the infrastructure problems, interviewing people and seeing the adaptations, conduct GPS measurement to see deformation, etc.), gather information from Government, from digital media, etc., and we noticed people increased their house, and the local goverment elevated the road and the bridge, etc. regulary over less decade periode as part of adaptation. We also noticed the Central Goverment built the dyke and pumping station. Our conclusions said that the adaptation only made temporaly since significant land subsidence keep coming and worsening by the sea level which is keep rising. Another conclusion, so far we have seen lack of mitigation program, monitoring or even inevective mitigation in Semarang related to this subsidence issue.Land subsidence is not a new phenomenon for Semarang. Some report said the subsidence in Semarang probably is occurring for more than 100 years. Based on the leveling surveys conducted by the Centre of Environmental Geology from 1999 to 2003 it was found that relatively large subsidence was detected around Semarang Harbor, Pondok Hasanuddin, Bandar Harjo and around Semarang Tawang Railway station, with the rates ranging from 1 to 17 cm/year. Results derived from GPS show that land subsidence in Semarang has spatial and temporal variations. In general, subsidence rates in Semarang have an average rate of about 6 to 7 cm/year, with maximum rates that can go up to 14-19 cm/year at certain locations. The impact of land subsidence in Semarang can be seen in several forms, such as the wider expansion of (coastal) flooding areas “rob”, cracking of buildings and infrastructure, and increased inland sea water intrusion. It also badly influences the quality and amenity of the living environment and life (e.g. healt...

Landslide monitoring using terrestrial laser scanner and robotic total station in Rancabali, West Java (Indonesia)

West Java is one of the provinces in Indonesia which is prone to landslide. Over the past few years, landslides in this area have resulted in a large number of victims. One of the areas in West Java with the highest risk of landslide occurrence is Rancabali Ciwidey. In general, the morphology around the landslide location is steep hills, with the slope > 30° and the altitude between 1550 – 1865 m above sea level. Several indications of ground movements can be seen in the form of slumps and cracks on the village roads and tea plantation, as well as slanting trees and electricity poles. The ground movement monitoring in this area is necessary for disaster mitigation. Several methods that can be used to monitor the landslide are using Terrestrial Laser Scanner (TLS) and robotic total station. This research aims is monitoring the landslide using these methods. The methodology used in this research is by obtaining the scanning data using TLS C-10 and Robotic total station MS05 measurements to obtain the coordi...

Preliminary co-sesimic deformation model for Indonesia geospatial reference system 2013

In the October 11st 2013, Indonesia introduced the new national geodetic datum which called as Sistem Referensi Geospasial Indonesia 2013 (Indonesian Geospatial Reference System 2013). This is a semi dynamic datum in natural, which the reference epoch define at 2012.0 and the coordinates change due to plate motion and earthquake was accommodate using a deformation model. One of the components of deformation model is co-seismic deformation due to earthquake. In this study we estimate the co-seismic deformation model based on GPS time series data and earthquake geometry parameter. We used 4 major earthquakes with the magnitude > 8 Mw that occurred in the Indonesia region since 2004. Our result shows the rmse of residual co-seismic deformation from both method (GPS and earthquake modeling) in the East and North components is 4.10 mm and 5.26 mm for Sumatra Andaman 2004 EQ, 46.68 mm and 178.92 mm for Sumatra Utara 2005 EQ, 140.42 mm and 171.00 mm for Sumatra Selatan 2007 EQ, and 14.29 mm and 9.73 mm for Whart...

Implementation of M6.5 Pidie Jaya earthquake’s deformation model for Indonesian geospatial reference system 2013

On Tuesday 06 December 2016, the magnitude 6.5 earthquake occurred near Pidie Jaya district of Aceh province, Indonesia. Indonesian National Board for Disaster Management reported, this earthquake causing 106 casualties, 700 injuries, 16238 house damages, and 85161 evacuate. The horizontal deformation due to this earthquake has been recorded by continuous GPS (cGPS) network belong to Geospatial Information Agency and National Land Agency. The nearest cGPS to the epicenter is around 32 km that has horizontal deformation about 2.5 cm to west and 0.5 cm to north direction. Using simple modeling, we estimate coseismic deformation due to this earthquake associated with the Indonesian Geospatial Reference System 2013 (IGRS2013) and the implementation.On Tuesday 06 December 2016, the magnitude 6.5 earthquake occurred near Pidie Jaya district of Aceh province, Indonesia. Indonesian National Board for Disaster Management reported, this earthquake causing 106 casualties, 700 injuries, 16238 house damages, and 85161 evacuate. The horizontal deformation due to this earthquake has been recorded by continuous GPS (cGPS) network belong to Geospatial Information Agency and National Land Agency. The nearest cGPS to the epicenter is around 32 km that has horizontal deformation about 2.5 cm to west and 0.5 cm to north direction. Using simple modeling, we estimate coseismic deformation due to this earthquake associated with the Indonesian Geospatial Reference System 2013 (IGRS2013) and the implementation.

Investigating the tectonic subsidence on Java Island using GNSS GPS campaign and continuous

Many places around Java island are experiencing land subsidence with the rates vary from few centimeter to order of tens centimeter per year. Question arises on what would be the causes of the subsidence in the area. The tectonic is one of the suspected causes along with anthropogenic causes (e.g. ground water overexploitation). The question is very important for proper and effective mitigation or adaptation. As we can see the impact from subsidence like damaging on infrastructures, wider area expansion of flood, etc. indeed they are formed a quite serious disaster now. If the tectonic play significant role, in this case the adaptation is more effective than mitigation, etc. GNSS GPS technology is a passive, all-weather satellite-based navigation and positioning system, which is designed to provide precise three dimensional positions and velocity, as well as time information on a continuous worldwide basis. In the context of subsidence as we highlight above, GPS could provide very accurate level (millimeter level) to determine the subsidence signal if existed. This paper will highligt the investigation of tectonic subsidence over Java island by using data measurements from GNSS campaign and continue. Our preliminary result shows no tectonic subsidence over Java island.Many places around Java island are experiencing land subsidence with the rates vary from few centimeter to order of tens centimeter per year. Question arises on what would be the causes of the subsidence in the area. The tectonic is one of the suspected causes along with anthropogenic causes (e.g. ground water overexploitation). The question is very important for proper and effective mitigation or adaptation. As we can see the impact from subsidence like damaging on infrastructures, wider area expansion of flood, etc. indeed they are formed a quite serious disaster now. If the tectonic play significant role, in this case the adaptation is more effective than mitigation, etc. GNSS GPS technology is a passive, all-weather satellite-based navigation and positioning system, which is designed to provide precise three dimensional positions and velocity, as well as time information on a continuous worldwide basis. In the context of subsidence as we highlight above, GPS could provide very accurate level (millimet...

Early pictures of global climate change impact to the coastal area (North West of Demak Central Java Indonesia)

In the last several decades we have been realized for the Global Climate Change situation. Some indicators are worldwide increasing temperature, decreasing volume of ice in Antarctica, and the sea level rise. Relating to the decreased of ice volume and the sea level rise, this situation has been predicted to endanger the living at the coastal area in the future. Prediction models have shown some coastal cities area would suffer flood by tidal inundation and even permanent flooding. Coincidently, today in the North West of Demak District Central Java Indonesia we literally can see the early picture of Global Climate Change impact to the coastal areas as mention. The occurrence of tidal inundation in this area was recognized at least in the early 2000 and even earlier, and in the recent years the tidal inundation comes not only at a high tide but even at the regular tide, and in fact some of this area are obviously sinking to the sea through times. This early picture is truly showing a disaster. Adaptation ...