Category: International Issues
Water resources engineers and hydrologists would find immensely useful an established classification methodology or model that correctly captures the hydrological behavior of sub-basins or catchments along a river and groups them according to sub-basin-scale characteristics exhibited. Such a robust and reproducible method of classification of sub-basins especially along transboundary rivers could help improve hydrological modeling and refine the spatial and temporal resolution of information about adjoining catchments especially under changing natural and anthropogenic influences.
However, there currently exists no universally accepted criteria for hydrological classification of catchments. Some studies have applied hydrological models to catchment classification based upon criteria like streamflow regimes, hydrologic similarity, and hydroclimatic factors. Some constraints include geographic or situational limitations of models and large numbers of model parameters and data involved. The latter is undesirable because the main purpose of catchment classification is to decrease the complexity of water systems by grouping them into several identical categories. This study applied and compared four methods of classifying catchments (empirical runoff equations, quasi-runoff coefficients, Muskingum-Cunge routing, and exceedance probabilities) in a major transboundary river known for water security issues. Using predefined classification criteria, the results produced five distinct catchments which were homogenous across all four methods and suggest that a combination of different methodology may be needed for reliably classifying catchments. Scientists and water policy makers could use the methodology and information gathered in planning for irrigation, flood risk management, river discharge modelling, improving dam storage and release policies, and optimizing food-water-energy nexus in the region.
Assistant Professor, Department of Civil Engineering