Application of geospatial technologies for multi-hazard mapping and characterization of associated risk at local scale

Abstract

In this study multi-hazard risk assessment is carried out in Arithang ward, one of the major wards within Gangtok Municipal Corporation, with the objectives of (a) landslide and earthquake hazard mapping of Gangtok city with analytical hierarchy process (b) vulnerability mapping in Arithang ward and (c) semiquantitative and semiqualitative risk analysis. Landslide hazard zonation (LHZ) depicts that very high and high hazard zone occupies 6% and 17% of the Gangtok city whereas 60% and 18% of area falls under medium and low hazard category respectively. With respect to seismic hazard susceptibility 13% and 22% of area falls under very high and high category respectively. Semiquantitative risk analysis reveals that majority of the residential buildings are concentrated in low earthquake and landslide hazard zone followed by 39% and 35% within medium class. Only 0.6% and 7% of residential buildings are found in high earthquake and landslide hazard zones. Bamboo and wood made buildings are found to cluster within very high class of landslide hazard. About 61% of multistoried buildings are placed within low zone of LHZ. Risk analysis reveals that buildings at the eastern and western part of Arithang ward come under high risk with respect to earthquake and landslide.

Knowledge-driven method: a tool for landslide susceptibility zonation (LSZ)

“…In landslide studies, past data are used to prepare the inventory. Generally, two types of inventory are developed for landslide susceptibility zonation, i.e., landslide inventory map (Basharat et al 2016;Kaur et al, 2018) and event landslide inventory map (Guzzetti et al 2012;Mondini and Chang 2014). Landslide inventory map shows the location and spatial extent whereas event landslide inventory indicates the extent, location, and typology of landslide hazard caused by triggering factors.…”

“…Liquefaction by itself does not directly initiate any particular hazard but rather act as isolator during seismic shaking by impeding the transmission of vibrational energy (Ambraseys, 1973;Kaur et al, 2018). Soil liquefaction initiates some ground failures due to temporary or permanent movement of ground and becomes one of the most important attributes to landslide (Chung & Fabbri, 2008).…”

Sensitivity analysis and mapping the potential groundwater vulnerability zones in Birbhum district, India: A comparative approach between vulnerability models

“…SRC constructed from the training dataset gives the prediction map but it does not convey the accuracy of prediction. Hence, to evaluate the future prediction accuracy of the model prediction rate curve (PRC) is implemented (Chung and Fabbri, 2003;Kaur et al, 2017Kaur et al, , 2008Thapa et al, 2017c). In PRC plotting the cumulative percentage of susceptible areas on the x-axis is compared against the cumulative percentage of nitrate occurrence in the test dataset on the y-axis.…”

The key role of hazard indices and hotspot in disaster risk management: the case study of Napoli and Pozzuoli municipalities (Southern Italy)

“…In this context, multi-hazard studies are fundamental (Bathrellos, Skilodimou, Chousianitis, Youssef, & Pradhan, 2017;Kappes, Keiler, von Elverfeldt, & Glade, 2012;Kaur, Gupta, Parkash, & Thapa, 2018;Yordanova & Curt, 2018), since they evidence all threats impending on a metropolitan area and consequently the correct strategies to reduce the risks. Multi-hazard can be seen as the process of assessing the role and effects of various independent hazards endangering the same area or as a process dealing with the possible interactions among different hazardous events (Garcia-Aristizabal et al, 2014).…”