Citation

Luo M, Criss RE. Nat. Hazards 2017; 88(1): 559-574.

Copyright

(Copyright © 2017, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s11069-017-2880-9

PMID

unavailable

Abstract

A novel stage projection method is used to estimate present-day flood levels at 12 sites on the Missouri River, using present-day rating curves and historical discharge estimates. These results are compared to several other flood estimates, including methods based only on historical stage data, and official "100-year" flood (base flood) levels determined from the statistics of discharge. Differences among these estimates vary with location, and their utility depends on river management style. At sites in the upper basin, channel configuration has changed little, but peak discharges have decreased slightly, due to tributary reservoirs and withdrawals. Little difference is seen between the various estimates of flood levels, and historical changes appear to be minimal. In contrast, flow behavior and channel character have been drastically modified along the middle Missouri River by a system of dams and huge reservoirs that were constructed and filled between 1933 and 1964; estimates of flood levels depend on location relative to these facilities. Further downstream, the lower Missouri River is lined with levees and has been transformed into a narrow navigational channel.

RESULTS are complex at and above Kansas City, because the channel at many sites has become incised due to decreased sediment loads. Below Kansas City, the water levels of significant floods are now higher than historical values, and official base flood levels are underestimated. Profound changes to the Missouri River have destabilized it in many complex ways, causing it to be less predictable, and many decades or centuries will be required for a new state of equilibrium to develop.

Language: en