Geology topics
Research about Missouri
Source-linked reports with geographic coverage including Missouri.
Historical land-use changes and potential effects on stream disturbance in the Ozark Plateaus, Missouri
Land-use changes have been blamed for creating disturbance in the morphology of streams in the Ozark Plateaus, Missouri (hereafter referred to as the Ozarks). Historical evidence and stratigraphic observations document that streams have been aggraded by substantial quantities of gravel beginning sometime at or near the time of European settlement of the Ozarks. Before European settlement, streams were depositing a mixed sediment load of gravel bedload and silty over-bank sediment. Observations of early explorers conspicuously lack descriptions of extensive gravel bars; observations of geologists working during the middle to late 1800's before significant land-use disturbance, however, include descriptions of large quantities of gravel in stream banks and beds. The first change in land cover as settlement progressed from the early 1800's to approximately 1880 was replacement of valley-bottom forest with cultivated fields and pastures. At the same time, suppression of wildfires in the uplands caused an increase of woodland with woody understory at the expense of grassland and oak savannah. Valley-bottom clearing probably initiated some direct disturbance of stream channels, but fire suppression would have decreased runoff and sediment yield from uplands. Beginning sometime during 1870 to 1880 and continuing until 1920, commercial timber companies began large operations in the Ozarks harvesting shortleaf pine for sawlogs and oak for railroad ties. Selective cutting of large timber, use of livestock for skidding logs from the forest, and avoidance of the steeper slopes minimized the effect of this phase of logging on runoff and sediment supply of uplands and valley-side slopes. Continued decreases in the erosional resistance of valley bottoms through clearing and road building, and the incidence of extreme regional floods from 1895 to 1915, probably caused initiation of moderate stream disturbance. This hypothesis is supported by historical and oral-historical observations that stream instability began before the peak of upland destabilization from 1920 to 1960. The post-Timber-boom period (1920 to 1960) included the institution of annual burning of uplands and cut-over valley-side slopes, increased grazing on open range, and increased use of marginal land for cultivated crops. Models for land-use controls on annual runoff, storm runoff, and soil erosion indicate this period should have been the most effective in creating stream disturbance. Written historical sources and oral-historical accounts indicate that erosion was notable mainly on lands in row-crop cultivation. Oral-history respondents consistently recall that smaller streams had more discharge for longer periods during 1920 to 1960 than during 1960 to 1993; many additionally observed that floods are "flashier" under present-day (1993) conditions. Changes in the timing of hydrographs probably relate to changes in upland and riparian zone vegetation that decreased storage and flow resistance. Probably the most destabilizing effect on Ozarks stream channels during this period was caused by livestock on the open range that concentrated in valley bottoms and destroyed riparian vegetation in the channels and on banks. Destruction of riparian vegetation in small valleys may have encouraged headward migration of channels, resulting in extension of the drainage network and accelerated release of gravel from storage in the small valleys. This hypothesis is supported by lack of other sources for the large quantity of gravel in Ozarks streams and oral-historical observations that gravel came out of the runs, rather than from slopes. From 1960 to 1993, cultivated fields and total improved land in farms decreased, but cattle populations continued to increase. This increase in grazing density has the potential to maintain runoff and sediment delivery to streams at rates higher than natural background rates. Whereas some riparian zones have been allowed to grow up into bottom-land forest, this stabilizing effect occurs on only a small part of valley-bottom land. Recovery processes aided by riparian vegetation are limited by channel instability and frequent, large floods.
Geology of the Coffman 7 1/2' quadrangle, Ste. Genevieve County, Missouri
No abstract available.
Geologic map of the Minnith 7.5 min. quadrangle, Ste. Genevieve and Perry Counties, Missouri
No abstract available.
Water resources data, Missouri, water year 1994
The U.S. Geological Survey, Water Resources Division, in cooperation with local, State, and Federal agencies and organizations, obtains a large quantity of data pertaining to the water resources of Missouri each water year (October 1 to September 30). These data, accumulated during the water years, constitute a valuable data base for developing an improved understanding of the water resources of Missouri. Water-resources data for the 1994 water year for Missouri consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and ground-water levels. This volume contains discharge records for 102 gaging stations; stage at 12 lakes and reservoirs; water quality at 54 sampling stations (including 2 lakes and reservoirs); and water-level records for 8 ground-water monitoring wells.
Simulation of rainfall-runoff for basins in the Rolla, Missouri, area
Important rainfall-runoff characteristics for basins in the Rolla, Missouri, area were determined to be overland flow, interception storage, interception losses, evaporation, and infiltration. Using these characteristics, the U.S. Environmental Protection Agency's Stormwater Management Model (SWMM) was configured for basins in the study area. The data network for the model calibration consisted of four continuous rainfall gages and three continuous streamflow gages. The model was calibrated, using observed data from three runoff events, by minimizing objective functions representing peak discharge, volume of runoff, and time to peak discharge from the beginning of simulation. The absolute mean percentage difference between the simulated and observed data for peak discharge, volume of runoff, and time to peak discharge are 9.47, 10.8, and 19.6 percent. A sensitivity analysis of SWMM parameters was performed on a simplified drainage basin. The output of runoff (volume, peak, and timing) in SWMM was determined to be most sensitive to subarea width, percentage impervious area, saturated hydraulic conductivity, and initial moisture deficit. The volume of runoff was affected by percentage impervious area, saturated hydraulic conductivity, and initial moisture deficit. The peak flow rate was affected by subcatchment width and percentage impervious area, whereas the time to peak was affected by subcatchment width. The model also was determined to be sensitive to the time step in the streamflow routing part.
Investigation of bridge scour at selected sites on Missouri streams
Scour around bridge piers is a major concern in the design of a new bridge or the evaluation of the structural stability of an existing bridge. An adequate estimation of potential scour at bridge piers is essential to effective design, construction, and maintenance of hydraulic structures. Reasonably accurate estimates of scour depth are needed for safe, cost-effective bridge design. Although many equations have been developed on the basis of laboratory work that can be used to estimate local scour at piers, site-specific data have not previously been collected to verify the accuracy of these equations or applicability to Missouri streams. Scour data were collected during floods at 10 sites on streams in Missouri. The recurrence intervals of the floods ranged from less than 2 to more than 50 years. Local-scour holes near bridge piers ranged from 0.5 to 7.1 feet deep. Seven local-pier-scour equations were evaluated as to their usefulness in estimating the measured scour at the sites studied. Scour depths estimated using the Froehlich equatin without a safety factor had an interquartile range nearest in magnitude to the interquartile range of the measured scour depths. None of the medians of scour depths estimated using the seven equations were statistically equal to the median of the measured scour depths at a 0.05 level of significance. However, the Froehlich equation without a safety factor provided the "best fit" estimates of the equations considered. Contraction scour exceeded local scour by several times in some cases. Total scour of approximately 19 feet, largely becasue of contraction scour, was measured at the Chariton River near Prairie Hill during the flood of July 8, 1993. This large scour was, in part, the result of an accumulation of woody debris de- creasing the bridge-opening area. A bridge on State Highway 32 near Lebanon over North Cobb Creek (drainage area 52.5 square miles) was destroyed during the flood of May 26, 1990. Bridge scour attributable to contraction of the flood flow caused this loss.
Surface-water and sediment quality in the Old Lead Belt, southeastern Missouri– 1988-89
No abstract available.
Discharge rating for tainter gates at lock and dam no 24 on the Mississippi River at Clarksville, Missouri
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Discharge ratings for tainter and roller gates at lock and dam No. 25 on the Mississippi River near Winfield, Missouri
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