Within the water cycle, physical and chemical interactions between water, air and land shape the Earth’s surface. Human activity also induces major changes to natural systems at a wide range of temporal and spatial scales. Experimental methods have played – and still play – a fundamental role in Hydrology and Hydraulics. Laboratory- and field-based experiments allow physical systems to be analysed under semi-controlled conditions to understand process–form interactions. As such, experimental studies provide an effective platform for investigating physical processes under controlled hydrometeorological or physical conditions and improving understanding of the Earth systems.

Experimental research contributions across a series of disciplines with a hydrological, hydraulic, and geomorphological focus across a wide range of spatiotemporal scales are welcomed for submission to this Special Issue. We are particularly interested in recent scientific breakthroughs from experimental research in this field. Therefore, we welcome submissions focusing on (but not restricted to) the following.

• The use of laboratory- and field-based experiments to understand real-world physical systems with a hydrological, geomorphological or hydraulic focus
• Physical and experimental models such as flumes, lysimeters, soil columns, rainfall simulators or scaled physical systems
• Novel techniques for monitoring or data analysis, capable of increasing our insight into hydrological and hydraulic processes taking place in natural or urban areas
• Specifically designed facilities or setups to aid understanding and modelling of complex hydrological and hydraulic processes, such as the interactions of soil, air and water
• Development and application of hybrid or composite (numerical–physical) models contributing towards advanced hydrological and hydraulic modelling (e.g. real-time flood modelling)