Liquefaction Risk Zoning in Silakhor Plain

Liquefaction appears in saturation conditions in sandy to silty unconsolidated soils. When seismic loads of earthquakes stresses on suitable masses of soils for liquefaction, these soils tend to reduce their volumes, this leads to liquids trap inside the soil and water in pores pressure increases, so effective shear stress decreases inside the soil and liquefaction appears. This phenomenon during an earthquake can lead to geomorphic changes on the surface of the earth and causes damages on human foundations. Recognizing and zonation of suitable areas for liquefaction alongside by determining risk potential areas can help us to reduce damages during an earthquake. In this research, by using IRS remotely sensed data and overlying digitized layers of geologic and seismic areas, underground water table level, and geomorphologic landform characteristics, a liquefaction zoning map were produced for Silakhor plain west of Iran which shows 7 class of potential risk areas. Based on this map, 7 percent of study area located on very high level risk of liquefaction, 21 percent on risk class 5, 5 percent on risk class 4, 4 percent on risk class 3, 5 percent on risk class 2, 30 percent on risk class 1 and 28 percent on class zero.