Upmanu Lall is a leading expert on hydroclimatology, climate change adaptation, risk analysis and mitigation. His research has emphasized hydrology, water resource systems analysis, operations research and stochastic processes with applications to flood/drought risk and uncertainty assessment and the design and operation of water systems. He has pioneered the application of techniques from (a) nonlinear dynamical systems, (b) nonparametric methods of function estimation and their application to spatio-temporal dynamical systems, and (c) the study of multi-scale climate variability and change as an integral component of hydrologic systems.
As new knowledge was created in these areas, he has focused on its application to water resources management through innovation in adaptive or dynamic risk management methods that can use information on the structure of climate for simulation or forecasting. Recently, he has become concerned with the issue of global and regional water sustainability, and the more general issue of modeling and managing planetary change due to coupled human and natural dynamics. He is developing technical and policy tools for the projection and management of environmental change as part of a quantitative approach to sustainability of earth systems.