Resurvey of cross sections on the Green River in Browns Park, Colorado and Utah

This study resurveyed ten previously established cross sections and established eight new cross sections on the Green River in Browns Park to document changes in channel width, depth, and area since earlier surveys conducted in 1994. The measured area of the channel cross sections on the Green River in Browns Park generally increased between the initial surveys and 2019. This increase in cross-sectional area was observed in nine of the ten resurveyed cross sections and is indicative of net sediment erosion. The increase in cross sectional area occurred through both channel widening (bank retreat) and increases in depth (bed incision). An analysis of the contribution of bank versus bed changes to the overall area change suggests that the erosion is mostly from the bed of the channel. In addition, weak longitudinal trends in the bed-sand grain-size distribution are consistent with progressive depletion of the sand stored on the bed of the Green River in Browns Park. The findings from our cross-section resurvey support the conclusion that the Green River in Browns Park is experiencing progressive sediment loss and is in a state of sediment deficit.