Separating drought and impoundment signals in regulated dryland rivers: data products, code and figures for the Senegal basin (1903-2019).

Derived data products, processing code and figures supporting Thiam, Faty and Niang, "Separating drought and impoundment signals in regulated dryland rivers: a paired observed-naturalised attribution design applied to the Senegal basin (1903-2019)", submitted to Journal of Hydrology: Regional Studies. In dryland basins the decades in which flow regimes shifted are often the decades in which the rivers were impounded, so climatic and infrastructural signals are confounded in the observational record. This deposit supports a design that separates them, combining a contrast between regulated and unregulated gauges with a physically based naturalised reconstruction used as a formal climate-only counterfactual rather than as a gap-filling tool. The analysis covers 3 582 748 daily discharge records from 44 gauges on the Senegal River and its tributaries, of which 26 carry annual series long enough for change-point and Range of Variability analysis. It finds that annual volume is governed by climate, with mean annual discharge falling by 33 to 62 per cent and change points clustering between 1967 and 1971 at every station including those above every impoundment, while the regulation signal is confined to the shape of the intra-annual regime below Manantali. The deposit contains the five processing scripts, the figure scripts, the annual discharge series, the change-point results, the IHA parameters, the alteration matrix, the station metadata, the quality-control audit, the supplement workbook and the published figures. The raw IRD daily archive and the harmonised daily series derived from it are not redistributed; everything downstream of the annual level is included, so all published results are recomputable.