Zoning of confined aquifers inrush and quicksand in Shanghai region.

Groundwater inrush and quicksand from the underlying aquifers are two typical geological hazards during underground constructions in Shanghai region, China. The objective of this work is to give a zoning study on confined aquifers and quicksand geology in Shanghai region and provide helpful decision-making information for the government, urban planners and designers. The hydrogeological characteristics of the confined aquifers in Shanghai are collected, and two different criteria are then proposed for mapping the aquifers. The characteristics and distribution of the soil stratum, in which quicksand would occur, are then presented, and an index system for quicksand hazard and vulnerability assessment is proposed. Furthermore, the quicksand risk in different zones of Shanghai is evaluated using a semiquantitative approach, and the management zoning is developed by considering the urban planning of Shanghai. The zoning maps of confined aquifers and quicksand risk are obtained, and the high-risk zone can be directly identified from the zoning maps. This is greatly helpful for the future urban planning and underground constructions in Shanghai region. The proposed method for quicksand hazard and vulnerability assessment is also applicable for other cities undergoing geological hazards caused by confined water inrush and quicksand. [ABSTRACT FROM AUTHOR]