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Chapter II
Hazard Analysis: Ground Stability Analysis in Urban Area
2.1 Introduction
Earthquakes are considered as natural hazards, which become the main interest of environment experts. Impacts of earthquakes are producing environment physical
damage until cause of death. Refers to BNPB 2007, the impact of earthquake caused at least 120.000 death victims among 2002 to 2006. That impact also
brought economic loss and regional development incline. Experiences in Aceh tsunami 2004, Yogyakarta earthquake 2006, and the newest occurrence in
Padang 2009 made experts to reach solution to minimize the impacts of earthquake.
The effort to avoid impact of earthquake hazard uses mitigation approach, which can be depend as an activity to avoid impact of natural hazard or manmade hazard
for public and nation Sutikno, 2006. Mitigation is divided into two
important parts, structural and nonCstructural. Structural mitigation is done by structural approach such as land suitability, building resistance, type of material
structure, and etc. Non structural mitigation is done by “soft structure” such as dissemination, education, training, institution development, etc. Both of concepts
should parallel in those implementations. Spatial planning is a part of nonCstructural mitigation, which considers all of
hazard and the impacts. Based on hazard and the impacts, land use planning and regulation should consider hazard potential and susceptibility. In case of
earthquake hazard, geological information and phenomena are important factors to support what we should do and determine on the surface.
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Spatial planning process must be supported by geological information to identify where location susceptible from earthquake hazard. By using geographic
information system GIS can manage and utilization of earthquake hazard information DGME, 2004. Spatial analysis capability in GIS is possible to
produce hazard map, which is become important part in land use planning process.
2.2 Objective of Research
The objective of earthquake hazard in this research to determine hazard area based on geological information by using GIS spatial analysis. Geological information
consist of 4 four main factors which influence to ground stability; rock structure, slope, earthquake intensity, and fault way.
2.3 Literature Review 2.3.1
Definition of Hazard
Hazard is potentially damaging physical event, phenomenon, or human activity that may cause the loss of life or injury, property damage, social and economic
disruption, or environmental degradation ISDR, 2007. Following the ISDR term, hazard can include latent conditions that may represent future threats and have
different origins: natural geological, hydroCmeteorological and biological or induced by human processes environmental degradation and technological
hazards. Hazard can be single, sequential or combined in their origin and effects. Each hazard is characterized by its location, intensity, frequency and probability
ISDR, 2007. 2.3.2
Geological Hazard
One of the types of hazard is cause by natural factor. As mentioned by International Strategy Disaster Reduction ISDR, natural hazard is classify into 3
three types; by geological, hydro meteorological, and technological hazards. Geological hazards are dangerous situation caused by geological processes. The
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