In this paper, the current methods for predicting surface subsidence due to
underground coal mining are evaluated first. A single index, called a strata
parameter (P), is then proposed to describe the overall character of the
undermined strata in the context of surface subsidence. Based on the
strata parameter, a method for predicting the maximum surface
subsidence for various panel width (w)/depth (h) ratios is presented,
which has been tested against specific empirical curves or data from
several coalfields in different countries. From the data relating to several
coalfields, a linear relationship between the reported average angle of
draw and the strata parameter has been established. It has also been found
that the strata parameter can be used for studying the locations of the
inflection points and the shapes of transverse subsidence profiles.