Pairwise IHA Analysis: Python Toolkit for Assessing Reservoir Impacts

Python-based tool for pairwise upstream-downstream IHA analysis at reservoirs and dams. Enables comparison of flow regime characteristics above and below impoundments to quantify the degree of hydrological alteration caused by dam operations. Uses pandas for data handling, calculates all 33 IHA parameters for paired stations, and computes deviation metrics to identify which flow components are most altered. Open-source and scriptable, suitable for batch analysis of multiple dam sites. Complements the TNC desktop software by providing flexible, programmatic analysis capabilities. Relevant for the Incomati Basin where major dams (Maguga, Driekoppies, Kwena) significantly alter downstream flow regimes — pairwise analysis can quantify the specific impact of each dam on IHA parameters.