1890's Land Cover/Use - Mississippi River Commission Surveys, Pool 11

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）针对密西西比河从伊利诺伊州开罗至明尼苏达州明尼阿波利斯的河段开展了大规模高分辨率测绘勘测。相关数据以89幅测绘地图及配套索引的形式正式公开发布。20世纪90年代，中西部上游环境科学中心（Upper Midwest Environmental Sciences Center, UMESC）联合美国陆军工程兵团负责密西西比河上游事务的密西西比河上游修复-环境管理计划下属的长期资源监测计划组成单元（Long Term Resource Monitoring Program, LTRMP），对地图中的土地覆盖/土地利用符号体系进行数字化处理，以此构建出世纪之交、筑坝前的土地覆盖与土地利用数据集。地图中未进行数字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（例如翼坝）、堤防、水准基点、铁路及城市街道。