1890's Land Cover/Use - Mississippi River Commission Surveys, Pool 2

In the late 1880's and early 1900's the Mississippi River Commission (MRC) conducted an extensive high-resolution survey of the Mississippi River from Cairo, Illinois to Minneapolis, Minnesota. These data were published as a series of 89 survey maps and index. In the 1990's, the Upper Midwest Environmental Sciences Center (UMESC) in conjunction with the US Army Corps of Engineers Upper Mississippi River Restoration- Environmental Management Program -- Long Term Resource Monitoring Program element (LTRMP) for the Upper Mississippi River automated the maps' land cover/use symbology to create a turn of the century/pre-impoundment land cover/use data set. Other data on the maps that were not automated include; elevation contours, water depth soundings, proposed water control structures (e.g., wing dams), levees, benchmarks, railroads, and city streets.

19世纪80年代末至20世纪初，密西西比河委员会（Mississippi River Commission, MRC）对从伊利诺伊州开罗市至明尼苏达州明尼阿波利斯市的密西西比河段开展了大规模高分辨率勘测。该勘测数据以89幅勘测地图及配套索引的形式正式发布。20世纪90年代，上中西部环境科学中心（Upper Midwest Environmental Sciences Center, UMESC）联合美国陆军工程兵团密西西比河上游修复-环境管理项目下属的密西西比河上游长期资源监测项目（Long Term Resource Monitoring Program, LTRMP），对上述地图的土地覆盖/利用符号体系进行自动化处理，构建出世纪之交、筑坝蓄水前的土地覆盖/利用数据集。地图中未被自动化处理的其他数据包括：高程等高线、水深测深数据、拟建水利控导设施（如翼型坝）、堤防、水准点、铁路及城市街道。