The CASCADE toolbox for analyzing river sediment connectivity and management

Abstract Sediment connectivity in rivers directly links to most fluvial processes and eco-system services. Modelling network-scale sediment connectivity and its response to anthropic alterations, such as dams or land-use changes, is key to better understanding river processes and to inform river basin management. This paper contributes a MatlabTM toolbox for network-scale sediment connectivity based on an implementation of the CASCADE (CAtchment Sediment Connectivity And DElivery) model. CASCADE combines concepts of graph theory with empirical sediment transport formulas to quantify sediment transfers between many connected sediment sources and sinks in a river network. Improved numerical efficiency compared to common hydrodynamic models enables application to large river networks, stochastic simulations of sediment connectivity, and screening impacts of many infrastructure portfolios. Input data requirements are flexible and basic functionality is available with globally available datasets to ensure applicability to poorly monitored basins. The toolbox offers options for customization and interactive output visualization tools.