Supplementary material to “New Databases Reveal 200 Years of Change on the Mississippi River System”
Jonathan Remo, Environmental Resource and Policy Program and Department of Geology, Southern Illinois University at Carbondale
Nicholas Pinter, Department of Geology, Southern Illinois University at Carbondale
Brian Ickes, USGS Upper Midwest Environmental Science Center, La Crosse, Wisconsin
Rueben Heine, Department of Geography, Augustana College, Rock Island, Illinois
Citation:
Remo, J. et al. (2008), New Databases Reveal 200 Years of Change on the Mississippi River System, Eos Trans. AGU, 89(14), 134–135.
[Full Article (pdf)]
New Databases Reveal 200 Years of Change on the Mississippi River System
Over the past two centuries, the Mississippi River system (MRS) has been dramatically altered to facilitate commercial navigation and provide flood control. Because of its long history of modification, rigorous measurements including maps, charts, surveys, and other data concerning the MRS are available from the past 200 years or longer. Comparison between historical reference conditions and modern conditions can document changes related to natural processes, human impacts, and river management practices and policies.
To show these changes, we have assembled a hydrologic database of approximately seven million measurements and a geospatial database consisting of 4878 map sheets dating back to 1765. The databases include nearly all available data sources for the navigable Mississippi River, the lower Missouri River, and the Illinois River (>4500 kilometers of waterways; see Figure 1). We have digitized all 81 map sets and georeferenced 48 of those map sets, meaning that the maps have been referenced in physical space for use in a geographic information system. The purpose for constructing these databases is to centralize and standardize these data sources and to make them broadly available for research and management. In this article we describe the data, the databases, and their dissemination.
Hydrologic Data
Stage measurements (water surface elevation) on the MRS date to 1796 at Natchez, Miss., although system-wide stage collection began only in 1871, when the U.S. secretary of the Army was directed to establish a flood warning system. Over time, five different agencies have monitored these stations: the National Weather Service (NWS), the Mississippi River Commission (MRC), the U.S. Army Signal Corps, the U.S. Army Corps of Engineers (USACE), and the U.S. Geological Survey (USGS). Today, the USACE maintains the stage network on the MRS.
Discharges (the amount of water per unit of time) were measured on the MRS by the USACE as early as 1838. Early discharges were compiled primarily to construct rating curves, which graphically relate stage to discharge. Additional discharge measurements were made between 1891 and the 1930s to update or extend these early rating curves. Around 1930, the USGS began collecting measured discharges on the upper Mississippi River (UMR), Illinois River (ILR), lower Missouri River (LOM), and middle Mississippi River (MMR), while discharges on the lower Mississippi River (LMR) were measured by the USACE. Today, the USGS and the USACE continue to collect discharge measurements at selected stage-measurement stations to update rating curves.
Hydrologic Database
We compiled nearly six million stage measurements for 253 stations along the MRS (see Figure 1). The majority of stages were obtained digitally either via data queries using a Web-based USACE utility (http://www.rivergages.com) or through site visits to USACE district offices. Nondigital stage data also were gathered during site visits and from other archival sources. In addition, we have identified at least 16 additional stations for which nondigital stage data are available.
This article also shows compiled daily discharge data for gaging stations along the MRS. Most discharge data from the UMR, ILR, LOM, and MMR were acquired from the USGS's National Water Information System (http://nwis.waterdata.usgs.gov/nwis/sw). Some additional early (pre-1930) discharges were added from the USACE and from nondigital archival sources. All discharge data from the LMR were obtained from the USACE or nondigital archival sources (see Table 1).
For each of the measurement stations, gage attribute parameters were compiled, including location, quality assurance, and data summary attributes. Data were screened for quality, and codes designating data quality were assigned to each observation.
Geospatial Data
The first descriptions of the Mississippi River, from which the earliest maps of the river were based, include observations from Hernando de Soto's North American expedition (1539–1541). Maps from the sixteenth century through the mid-eighteenth century generally consisted of crude traces of the river banks (called "planforms"), pictorial topographic information, and political information (e.g., location names, Indian nations, territory boundaries). Late eighteenth to mid-nineteenth century maps were generally compiled from measurements, observations, and sketches made during survey missions such as the Lewis and Clark expedition (1803–1806). These survey maps typically included improved planforms, general land cover information, political boundaries, and man-made structures. A few map sets possessed limited bathymetric observations.
During the late nineteenth century, the Mississippi River Commission (MRC; 1879) and the Missouri River Commission (1884) were established by Congress to facilitate river navigation and mitigate flooding on their respective waterways. Surveys were carried out by the USACE for the two commissions between 1876 and about 1900 from headwaters at Lake Itasca, Minn., to the mouth of the Mississippi River, and on the Missouri River from Three Forks, Mont., to the confluence with the Mississippi River. The products of these surveys were detailed maps that show channel planform, land cover, river engineering structures (e.g., levees, wing dikes, and revetments), and political data. In addition, the Mississippi River maps included detailed bathymetric, topographical, and bed material (sediment) data. The MRC directed another high-resolution survey of the LMR between 1911 and 1918 that included the same information.
Six major hydrographic surveys–one on the UMR, one on the ILR, and four on the LOM–were undertaken by the USACE between 1910 and 1930. The products of these surveys were detailed maps that showed channel planform, bathymetric data, land cover, engineering structures, and political data. The UMR and ILR maps also included floodplain topography. Since 1930, hydrographic surveys have been performed by the USACE on a district-by-district basis. Hydrographic surveys were performed nearly every decade from roughly 1940 through about 1990 along the LMR but less frequently along other reaches of the MRS. Recent (post-1996) bathymetric data have been collected by all of the USACE districts [USACE, 2002; Harmar, 2004]. However, these recent data sets were not compiled for this project.
Geospatial Database
The geospatial database compiled here consists of archival maps in digital format. Eighty-one map sets and other reach-scale geospatial data sources (see Table 2) were compiled. Maps acquired in paper form were scanned at 300–400 dpi, digitally adjusted (e.g., cropped, rotated, adjusted for brightness and contrast) as necessary, and saved in JPEG format or TIFF. Forty-eight map sets were rigorously rectified, by which image coordinates were converted into real-world coordinates. The horizontal positional accuracy of each map sheet was calculated as the root-mean-square error. If the horizontal root-mean-square error exceeded 10 meters for a map sheet, the reference points were redigitized until a value less than 10 meters was attained, a standard that was met for all but a few of our maps. Detailed metadata, including root-mean-square error for each map sheet, will be disseminated as part of the geospatial database.
In general, we view the earliest maps of the MRS (pre-1880s) as valuable for qualitative assessment rather than for most quantitative applications. This is because these maps sometimes lacked accurate scales and often did not possess reliable coordinate grids. The first maps we found fully suitable for rigorous quantitative analysis were the Mississippi and Missouri river commissions survey maps from the late 1800s. The primary challenge when working with maps from 1880 to roughly 1930 are their vertical data, but Pearson and Mick [2007] have developed corrections for converting elevation data on these maps into a modern datum.
Dissemination
Our research group at Southern Illinois University at Carbondale (SIUC) has partnered with the USGS's Upper Midwest Environmental Sciences Center (UMESC) to disseminate the hydrologic and geospatial databases described in this article. Transfer of the archival maps and the hydrologic database between SIUC and UMESC is now complete, and the geospatial lab at UMESC will serve these data via a Web-based interface. Data will become available in phases over the next 2 years as the map sets are prepared for distribution and metadata are finalized. Potential database users should check the UMESC Web site (http://www.umesc.usgs.gov/) for current status of the interface and data requests. With large-scale river restoration projects on the MRS now in advanced planning, as well as a broad range of ongoing research, we invite and encourage other workers to take advantage of these rich historical data sources.
Acknowledgments
This research was supported by the U.S. National Science Foundation under grants EAR-0229578 and BCS-0552364 and by the USACE through the USGS's Upper Midwest Environmental Sciences Center for the Long Term Resource Monitoring Program (grant 07ERSA0263). We would also like to acknowledge Linda Leake, John C. Nelson, and Tim Fox of the Geospatial Sciences and Decision Support Laboratory at UMESC for their assistance with this project.
References
Harmar, O. P. (2004), Morphological and process dynamic of the lower Mississippi River, Ph.D. thesis, Univ. of Nottingham, Nottingham, U.K.
Pearson, C., and D. Mick (2007), Legacy height datums used on the Mississippi, Illinois, and Ohio river systems, paper presented at the American Congress on Surveying and Mapping Conference, Washington, D. C., 9 March. (Available at http://www.acsm.net/sessions07/pearson3111.pdf)
U.S. Army Corps of Engineers (2002), Interim report for the upper Mississippi River– Illinois Waterway System Navigation Study: Inventory of hydrographic survey and cross-section data available on the upper Mississippi River and Illinois waterway at the U.S. Army Engineer Districts, St. Paul, Rock Island, and St. Louis, Vicksburg, Miss.
Jonathan Remo, Environmental Resource and Policy Program and Department of Geology, Southern Illinois University at Carbondale; E-mail: diamict@siu.edu; Nicholas Pinter, Department of Geology, Southern Illinois University; Brian Ickes, USGS Upper Midwest Environmental Science Center, La Crosse, Wisc.; and Rueben Heine, Department of Geography, Augustana College, Rock Island, Ill.
Fig. 1. Map showing the river reaches for which geospatial data were compiled, and locations of the measurement and rated stations in the hydrologic database.
