GIS-based development of liquefaction hazard and soil distribution maps for Dinajpur Sadar, Bangladesh

The term "earthquake" now refers to a catastrophic event that occurs worldwide. Due to its geographical position, Dinajpur Sadar Upazila is the most vulnerable area for earthquake-based liquefaction. Evaluating the liquefaction resistance of loose saturated sand is a crucial component of geotechnical site characterization. This investigation aims to determine liquefaction hazards for Dinajpur Sadar and develop soil classification maps. The article uses a simplified method dependent on the Standard Penetration Test's blow count (SPT-N) to assess the liquefaction risk induced by the earthquake. SPT data was gathered at sixty locations within the study region. Liquefaction risk was evaluated at every location in an earthquake scenario with Mw = 6-8.5 using a 0.20 g peak horizontal ground acceleration (PGA). The liquefaction risk was predicted using the estimated liquefaction potential index (LPI) for each site. The LPI values in the studied area ranged from 0 to 28 for earthquakes of magnitude 7.5 with very low to very high risk. The LPI of discrete locations was then used to create a hazards map using geospatial techniques. Hazard map’s legends indicate that an increase in earthquake magnitude raises the LPI. For Mw=6, the area was determined to be safe against liquefaction; however, at Mw=8.5, it was found to be most vulnerable, with a maximum LPI of 42.7. For any earthquake magnitude, LPI was found to be minimal in the central and central-south parts of the study area. The northern and southwestern parts of the research sites exhibit significant liquefaction vulnerability. The soil classification maps depict that at any depth, silty sand and low plastic clay are covered by most of the region. The developed risk map might be a valuable indicator for the Bangladesh government's disaster mitigation scheme.