Bellinger and Kalang River estuaries erosion study
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A report prepared for Bellingen Shire Council. As with previous studies this report highlights that the steeper fluvially - dominated upper tidal reaches of the Bellinger River have eroded at a faster rate than the lower gradient fluvial - transition reaches on the Bellinger River. The data in dicates that the Bellinger River at all sites erodes/migrates at a faster rate than the Kalang River. This is inferred to be a function of more cohesive bank material and quality and extent of riparian vegetation in the Kalang River estuary. The photogramm etry data also indicate that the cross - sectional changes and migration rates cannot be explained solely by the hydrological regime in a given time interval. Net increases in channel capacity are commonly recorded in addition to areas of net deposition. A 6 - 33% net increase in width has been documented to have occurred since 1942 in 6/8 bends examined, with the greatest changes occurring in the upstream fluvial dominated reach of the Bellinger River. Channel capacity (cross - sectional area) on the lower Bel linger River for 5/8 bends show a 2 - 75% increase. Two bends (Bends 2 and 3) both record a 12 - 14% net reduction in channel capacity as a function of deposition on the low floodplain. Sites of accelerated change are identified on both the Bellinger and K alang Rivers.