Hydrodynamic Simulations of Physical Aquatic Habitat Availability for Pallid Sturgeon in the Lower Missour River, at Yankton, South Dakota, Kenslers Bend, Nebraska, Little Sioux, Iowa, and Miami, Missouri, 2006-07

摘要

Models of natural systems generally are classified into two categories: those used to predict and those used to increase understanding of the system. The focus of this report is the use of hydrodynamic models to increase understanding of what is suitable spawning and early-life-stage habitat for the Missouri River sturgeon and to address the sensitivity of habitat to flow variation. The modeling effort is exploratory and intended to elucidate relations between sturgeon and their environment. This work is a component of a suite of collaborative studies being carried out by the U.S. Geological Survey as part of the Comprehensive Sturgeon Research Program (Korschgen, 2007). The work is cooperatively funded through the U.S. Army Corps of Engineers Missouri River Recovery Integrated Science Program and the U.S. Geological Survey. The scope of the study was chosen to encompass a representative range of the hydrologic and geomorphic variability of the LMOR. The Miami reach is characterized by a navigation channel typical of the downstream 735 miles of the Missouri River and a flow regime that has recovered substantial amounts of inter- and intra-annual variability. The next upstream reach at Little Sioux has a typical navigation channel and a substantially altered flow regime. The Little Sioux and Miami reaches have been included in recent low-intensity restoration activities, including dike notching and unrooting dikes from the bank. Restoration activities in these two reaches varied minimally during the period of this study. The reach at Kenslers Bend reach has a simplified, engineered channel geometry and a highly altered flow regime. The most upstream reach at Yankton has a complex channel geometry and highly altered flow regime representative of the unchannelized segment of the LMOR river mile 753-811.