1. A method for determining optimum positions in a region for a plurality of sensors, wherein the sensors are capable of detecting occurrence of a hazard in the region, comprising: a. simulating occurrence and movement over time of the hazard in the region to produce data representative thereof; b. simulating interaction of the data representing movement of the hazard with data representing the sensors at each of a plurality of candidate locations in the region and for each of a plurality of sensor types; c. storing data resulting from the simulated interaction of the data representing the movement of the hazard with data representing the sensors at each of the plurality of candidate locations in the region for each of the plurality of sensor types; d. selecting one of a plurality of candidate sensor solutions, wherein each candidate sensor solution comprises one or more sensors of one or more sensor types at corresponding ones of the candidate locations; e. retrieving from the stored data the data for the selected candidate sensor solution; f. evaluating said data from said (e) retrieving with respect to performance criteria for the selected candidate sensor solution; and g. selecting another one of the plurality of candidate sensor solutions and repeating (e) and (f).