In some aspects, a stimulated reservoir volume (SRV) parameter for a stimulation treatment applied to a subterranean region is identified. A parameter of a fracture-plane network generated by application of the stimulation treatment is identified. A correlation between the SRV parameter and the fracture-plane network parameter is identified. In some implementations, the SRV and the fracture-plane network are computed based on microseismic event data associated with the stimulation treatment.