Lumped Conceptual Rainfall‐Runoff Models and Simple Water Balance Methods: Overview and Applications in Ungauged and Data Limited Regions

This article provides an overview of lumped conceptual rainfall‐runoff models and simple water and energy balance methods, with a focus on practical model applications to estimate runoff in gauged and ungauged catchments over large regions and to predict climate change impact on future runoff. The models are applied to a large data set across south‐eastern Australia to explore the effectiveness of the different model types under varying data availability. The conceptual rainfall‐runoff models are relatively simple tools for predicting runoff in catchments and large regions with sufficient observed streamflow data to calibrate the models. In data‐poor regions, the simple water balance methods can perform as well as the rainfall‐runoff models, particularly where only mean annual runoff estimates for broad‐scale assessments are required. Rainfall‐runoff modelling is a fairly mature science, and this article provides references to previous reviews and recent key papers, particularly on regionalisation studies to predict runoff in ungauged catchments. The study also discusses some of the more significant research areas currently being pursued as well as the use of lumped conceptual rainfall‐runoff models for climate change and land use impact studies.