1. A method of determining alarm conditions of a slope under inspection, the method including the steps of: (i) calculating one or more ratios for each of one or more time periods, each of the one or more ratios being calculated based on movement data in respect of at least a portion of the slope under inspection; (ii) selecting a maximum ratio from the one or more said ratios calculated in (i); (iii) comparing the maximum ratio with a threshold alarm value; and (iv) setting alarm conditions if the maximum ratio exceeds the threshold alarm value.