Measurement of liquid flow in open channels-Measurement in meandering rivers and in streams with unstable boundaries

This technical document outlines a standardized methodology for measuring liquid flow in open channels within meandering and winding rivers situated in unstable catchments. It provides specific guidance for field operations where traditional measurement techniques may be compromised by dynamic riverbed conditions or irregular channel geometry. The approach details the necessary procedural steps, instrumentation requirements, and calculation protocols to ensure data consistency and reliability across various hydraulic scenarios. Particular emphasis is placed on adapting measurement sequences to account for shifts in river morphology that commonly occur in such environments. By adhering to these prescribed protocols, practitioners can obtain accurate flow rate data essential for hydrological assessments, water resource management, and flood prediction models. The guidance covers aspects ranging from site selection and instrument placement to data correction methods required for complex flow patterns. This framework aims to establish a uniform reference for conducting hydrographic surveys in challenging fluvial systems, facilitating comparative analysis and long-term monitoring efforts without deviation from established engineering principles.