This study was carried out to assess land subsidence due to excessive groundwater abstraction in the northern region of Semarang City by integrating the application of both numerical models and geodetic measurements, particularly those based on the synthetic aperture radar interferometry (InSAR) technique. Since 1695, alluvial deposits caused by sedimentations have accumulated in the northern part of Semarang City, in turn resulting in changes in the coastline and land use up to the present. Commencing in 1900, excessive groundwater withdrawal from deep wells in the northern section of Semarang City has exacerbated natural compaction and aggravated the problem of land subsidence. In the current study, a groundwater model equivalent to the hydrogeological system in this area was developed using MODFLOW to simulate the hydromechanical coupling of groundwater flow and land subsidence. The numerical computation was performed starting with the steady-state flow model from the period of 1970 to 1990, followed by the model of transient flow and land subsidence from the period of 1990 to 2010. Our models were calibrated with deformation data from field measurements collected from various sources (e.g., leveling, GPS, and InSAR) for simulation of land subsidence, as well as with the hydraulic heads from observation wells for simulation of groundwater flow. Comparison of the results of our numerical calculations with recorded observations led to low RMSEs, yet high R2 values, mathematically indicating that the simulation outcomes are in good agreement with monitoring data. The findings in the present study also revealed that land subsidence arising from groundwater pumping poses a serious threat to the northern part of Semarang City. Two groundwater management measures are proposed and the future development of land subsidence is accordingly projected until 2050. Our study shows quantitatively that the greatest land subsidence occurs in Genuk District, with a magnitude of 36.8 mm/year. However, if the suggested groundwater management can be implemented, the rate and affected area of land subsidence can be reduced by up to 59% and 76%, respectively.

The 2006 Yogyakarta earthquake occurred at 05.55 West Indonesia Time, May 27, 2006 with a magnitude of Mw 5.9. The earthquake had a great trauma effect for the community, because there were many fatalities, around 6,000 people died. Therefore, it is very important to conduct research to determine the deformation that is currently happening around the Opak Fault. In this research, during 2016-2019, we collected products for Sentinel-1 synthetic aperture radar interferometry (InSAR) to measure the current fault deformation. The InSAR data was processed using LiCSBAS, a time series analysis kit of open-source SAR interferometry (InSAR) that integrates with the automated Sentinel-1 InSAR processor (LiCSAR). In the processing scheme for LiCSBAS, interferograms with many unwrapping errors are automatically detected and removed via loop closure. Reliable time series and velocities are extracted using several noise indices with the help of masking. The location of the Opak Fault can be detected clearly in the result because the deformation pattern around the fault is contrary different. The west of Opak Fault shows an uplift movement, while the deformation occurred in east area of the fault shows subsidence movement. Keywords : Opak Fault, Crustal Deformation, Sentinel-1 InSAR Data, LiCSBAS

Energy crisis that occurred in the world after being exploited on a large scale against fossil energy caused people has to think again about renewable energy. In Indonesia, the electricity consumption always increases every year with fossil energy dominating energy sources. Based on the Government Regulation number 79 of 2014, concerning the National Energy Policy, the Government of Indonesia has a national target in the implementation of renewable energy of 23% in 2025 and 31% in 2050. Information disclosure and development of geospatial technology is shown through the availability of information on the dimensions, location, and the height of objects on the surface of the earth through the open street map (OSM) website, one of which is the building. Digital Elevation Model (DEM/DEMNAS) data can be accessed through the Geospatial Information Agency (BIG) website. Utilization of this information can be done by utilizing QGIS and ArcGIS Pro software. The existence of an energy crisis and technological developments led to calculate Solar Radiation (contained in ArcGIS Pro) which can calculate the solar potential at a location based on three-dimensional building data, DEM, and solar intensity. Universitas Gadjah Mada (UGM) has announced their commitment in realizing new and renewable energy in Indonesia. Therefore, researchers intend to find out the solar potential in the UGM region in order to realize government programs in the application of new renewable energy. Based on the analysis done in this research, we get the amount of solar energy potential of 369.543 kWh/ m2/ day. Through this research we hope that UGM can become a pilot campus in the application of renewable energy, solar energy and can reduce the use of conventional electricity using fossil energy.Keywords: Solar Energy Potential, Three Dimensional Building, Open Street Map, UGM.

Nowadays, the era encompasses everything smart, whether they are smartphones, smart people, or smart cities. The term ‘Smart Cities’ refers to an advanced urban town that has well-connected infrastructure and communication through data centers and automated networks, unless for the energy system. Solar energy is one kind of renewable energy. It is a clean, sustainable, and free energy source both for the public and governments. With the rapidly growing technology, the yield of solar energy increases, while its cost reduces. Thus, it gains importance and becomes widespread. Presently, the increasing importance of solar power makes a hot topic. We are currently facing a global warming issue where one of the leading causes is the use of fossil energies. Non-fossil energy, or better known as renewable energy, is an option to reduce the use of fossil energy as an effort to minimize the impacts of global warming. In this study, we collected the data from The Unmanned Aerial Vehicle (UAV) that is combined with GPS and IMU technology to get the 3D campus model in National Cheng Kung University (NCKU), Taiwan. The output of the data is true ortho-image, digital surface model (DSM), and building footprint. The building footprint was processed using the Autodesk Insight 360 and Autodesk Revit to get better 3d campus model. All three data were processed using ArcGIS Pro using Calculate Solar Radiation plugin. The result of this step is reaching the solar energy potential of NCKU. The final step is to show it into the Web 3D GIS to display the result. From the Web 3D GIS, everyone can access the information of NCKU solar energy potential using computer and also smartphones.

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