In this paper, we propose a new sensor deployment strategy by considering both a probabilistic sensor detection model and a monitored area with geographical irregularity requirement of the sensed events. In this case, each point in the deployment field needs a specific minimum guarantee in event detection probability. The main objective is to find the minimum number of senors and their positions, in order to guarantee the requirement event detection threshold. Thus, we propose a new scalable deployment strategy based on virtual forces. The fundamental idea of our proposal is to adjust the number and the position of sensors according to virtual forces that must be computed for each sensor. The performance evaluation shows that our proposal obtained the best results compared to several other sensor deployment strategies founded in the literature.