Prof Liang's current research topics include flood risk management, water/soil/structure interactions and hydro-environment. He has studied shallow water flows, rainfall-runoff processes, ocean wave propagation and runup, scour and liquefaction around offshore structures, seepage and overtopping induced embankment failure, flow-like landslides, turbulent mixing and water pollution.

Prof Liang has developed several mesh-based and meshfree computational models for his research, and has expertise in digital image processing and its application in hydraulic experiments. He is the chairman of the local organising committee for the MPM2019 Conference, and has recently been sponsored by the Cambridge Centre for Smart Infrastructure and Construction and Trimble Fund to apply advanced drone technology to monitor floods and landslides.