Urban　power　and　gas　systems　(power-gas　systems)　are　crucial　components　of　lifeline　infrastructure.　Seismic　events　can　cause　varying　degrees　of　damage　to　structures,　equipment,　and　facilities　within　these　systems,　potentially　leading　to　a　reduction　or　loss　of　service　functionality.　This　paper　presents　a　model　for　assessing　the　seismic　connectivity　reliability　of　power-gas　systems,　based　on　non-uniform　seismic　ground　motions　and　seismic　vulnerability　models　of　system　components.　First,　a　spatially　non-uniform　seismic　ground　motion　field　is　generated　using　the　attenuation　relationships　of　seismic　parameters.　This　is　combined　with　seismic　vulnerability　models　of　key　components　in　power-gas　systems　to　calculate　the　failure　probabilities　of　these　components　under　varying　seismic　conditions.　Next,　to　address　the　uncertainty　in　component　seismic　damage,　the　Monte　Carlo　method　is　used　to　simulate　potential　damage　to　system　components.　Following　this,　the　connectivity　reliability　of　the　power-gas　system　nodes　is　evaluated　after　removing　the　damaged　components　from　the　system　network.　The　analysis　model　considers　the　failure　of　power　supply　nodes　near　gas　metering　stations,　which　can　lead　to　failures　at　gas　system　source　nodes,　and　the　failure　of　gas　supply　nodes　near　power　plants,　which　can　lead　to　failures　at　power　system　source　nodes.　The　framework　is　validated　using　the　IEEE　30-bus　power　system　and　a　47-node　gas　system.　The　results　reveal　that　spatial　variability　in　seismic　ground　motions　significantly　impacts　system　performance.　Compared　to　a　uniform　seismic　ground　motion　scenario,　the　connectivity　reliabilities　of　the　power　and　gas　systems　decrease　by　20.2%　and　18.7%,　respectively,　under　spatially　varying　seismic　conditions.　In　the　interdependent　power-gas　systems,　the　connectivity　reliabilities　of　the　power　and　gas　systems　decrease　by　9.4%　and　22.1%,　respectively.　In　spatial　seismic　ground　motions,　the　vulnerability　of　different　components　in　power　system　is　higher,　leading　to　lower　seismic　connectivity　reliability　of　the　power　system.　The　power　system　has　a　greater　impact　on　the　gas　system.　©　2024　Science　Press.　All　rights　reserved.