Global scale analysis on the extent of river channel belts.

Rivers form channel belts that encompass the area of the river channel and its associated levees, bars, splays and overbank landforms. The channel belt is critical for understanding the physical river evolution through time, predicting river behavior and management of freshwater resources. To date, there is no global-scale, quantitative study of the extent of river channel belts. Here we show, based on a pattern recognition algorithm, the global surface area of channel belts at an approximate 1 km resolution is 30.5 × 10km, seven times larger than the extent of river channels. We find 52% of river channels associated with the channel belts have a multi-threaded planform with the remaining 48% being single-threaded by surface area. The global channel belt (GCB) datasets provide new methods for high-resolution global scale landform classifications and for incorporating the channel belt into flood mitigation, freshwater budgets, ecosystem accounting and biogeochemical analyses.