Surface water assessment methods and tools for water resource management

Assessing surface water availability is important for resources planning and management. Surface water resources are vital for sustainable water management amid growing global water demand driven by population growth, urbanization, and agricultural and industrial expansion. Various methods are used to measure and analyse surface water availability, each with specific strengths and limitations. Direct measurement methods, such as timed-volume and dilution gauging, are accurate for small streams but limited in scale. Velocity-area techniques, including float and current meter methods, provide reliable stream flow estimates but require specialized equipment. Formed constriction methods, such as weirs and flumes, are effective but environmentally disruptive. Rainfall-runoff models like Cook’s Method, the Rational Method, and the Curve Number (CN) Method are widely used, though their accuracy varies based on watershed size and characteristics. Hydrological models, including SWAT, HEC-HMS, and MIKE SHE, simulate water movement across watersheds, with SWAT being particularly effective for long-term assessment of both surface and groundwater dynamics, especially in agricultural regions.