LATERAL DISCONTINUITIES ON THE PRE-ENGINEERED MISSOURI RIVER

The physical structure of modern-day large rivers often bears little resemblance to the pre-disturbance condition, and this radical transformation makes restoration targets difficult to delineate. In particular, the lateral dimensions of river form and connectivity are difficult to reconstruct due to intensive development of floodplain surfaces. Yet recently, the restoration of lateral connectivity has received increased attention thanks to the better understanding of its role in overall river ecosystem health. This paper presents the results of an exhaustive historical reconstruction of lateral side channel extent on the Missouri River between Kansas City and St. Louis. We use 1879 and 1894 Missouri River Commission surveys and 1928 aerial photographs to locate and digitize all side channels, quantifying metrics of side channel frequency and size along the river, giving us a better understanding of the pre-engineered lateral discontinuity of the Missouri River. Finally, we incorporate this data into a new conceptual model of lateral discontinuity intended to help guide side channel restoration on large rivers.