Dataset for centuries-scale forest-use legacy, sediment connectivity and riparian greening in Japanese rivers

This dataset supports the manuscript submitted to Geomorphology on the long-term effects of historical forest exploitation and post-war forest recovery on sediment connectivity, gravel-bar persistence and riparian greening in Japanese rivers. The dataset documents the principal derived data and analyses used in the manuscript, including the nationwide riparian vegetation trajectory for 109 Class A river systems in 1946, 1975 and 2013; site-scale environmental relationships; sediment-yield and river-slope analyses; dam-distance relationships; water-quality and temperature effects; and multivariable statistical results. Public hydrological and water-quality observations, including discharge, water level, BOD, TN and TP, were obtained from the Water Information System of the Ministry of Land, Infrastructure, Transport and Tourism, Japan (MLIT; https://www1.river.go.jp/). These public-source observations are identified by provenance and are not presented as newly generated data. The dataset is intended to support reproducibility of the analyses underlying the manuscript and to document the sources and derived variables used to evaluate the following conceptual pathway: historical forest exploitation → enhanced sediment delivery and gravel-bar renewal → limited persistence of riparian vegetation → post-war forest recovery → reduced coarse-sediment renewal → increased surface stability and riparian vegetation expansion. The repository also documents the distinction between national-scale long-term vegetation change and contemporary site-scale environmental modifiers.