A NUMERICAL-MODEL TO CALCULATE LAND SUBSIDENCE, APPLIED AT HANGU IN CHINA

The deep, unconsolidated sedimentary aquifers of eastern China are hea vily over-exploited and this causes aquifer compaction(1) which result s in land subsidence. The geological formation contains significant th icknesses of clay which introduces time delays between the extraction of the groundwater and the resulting subsidence. A new computer code c alled the Interbed Drainage Package has been developed for the popular MODFLOW model to address this behaviour. II has been applied in a sim ulation of the port of Hangu and the results are being used to manage the land subsidence problem. (C) 1995 Natural Environment Research Cou ncil. Published by Elsevier Science B.V.