Two-Gamma Reduced Analytical Hydrograph for SCS-CN Huff Design Storms

This archive is the reproducibility package for the paper "A Two-Gamma Reduced Analytical Hydrograph for SCS-CN Huff Design Storms." The archive contains the code, input data, processed results, figures, and supplemental material used to develop and evaluate a reduced analytical hydrograph for SCS-CN Huff design storms. Contents of the archive: Supplemental material: a PDF with the expanded derivations, quartile-specific equations, and worked supporting examples referenced by the study. Core source code: Python scripts implementing the continuous SCS-CN/Huff reference hydrograph and the reduced two-gamma hydrograph formulation. Direct-use implementations: standalone Python and MATLAB functions that allow users to compute the hydrograph and its parameter sensitivities from design inputs. Brazilian catchment dataset: a prepared HyBAS-12 catchment table used in the real-catchment design-input validation. This table includes catchment attributes used in the study, such as drainage area, curve number, relief-based variables, and supporting fields for the Brazilian application. IDF raster parameter data: raster files containing the intensity-duration-frequency parameter fields used to compute 25-year rainfall inputs for the Brazilian validation cases. Generated results: CSV tables with the outputs used in the manuscript, including design-grid simulations, validation metrics, sensitivity analyses, worked examples, fitted coefficients, and Brazilian application results. Figures: publication figures and editable figure files used in the manuscript and supplement. Documentation: README, manifest, dependency list, and Zenodo description files for reuse and verification. Types of data included in the results folder: synthetic design-grid outputs across Huff quartiles and hydrologic parameter combinations; reduced-model coefficient tables; performance metrics comparing the reduced hydrograph against the continuous reference solution; curve-number and time-of-concentration sensitivity results; worked example outputs for direct inspection; and Brazilian HyBAS-12 validation summaries and catchment-by-catchment results. The archive is intended to allow readers to reproduce the analyses, inspect the input datasets, reuse the direct hydrograph functions, and trace how each table and figure in the study was generated.