A ratio (measurement, characteristic, attribute) is a figure based on a particular spatial unit and employed in the fields of geography, spatial planning and environmental research. Parameters which have an indicative function for spatial features, terms or process not immediately perceivable have the status of indicators.

More narrowly, ratios can be employed as indicators to provide answers to specific questions (for example: the parameter "proportion of surface water to total area" can be used to calculate the numbers of waterfowl in a reference area). Thus for purely practical reasons the Monitor of Settlement and Open Space Development does not make a clear distinction between ratios and indicators.