UMRS Floodplain Inundation Attributes

Floodplain inundation is believed to be the dominant physical driver of an array of ecosystem patterns and processes in the Upper Mississippi River System (UMRS). Here, we present the results of a geospatial surface-water connectivity model in support of ecological investigations fully described in the USGS Open File Report entitled Indicators of Ecosystem Structure and Function for the Upper Mississippi River System (De Jager et al., in review). Briefly, we identified likely instances of floodplain submergence by comparing a daily time series of gage-derived water surface elevations to topo-bathymetric data modified to account for slopes and hydrologic routing. The resulting raster attribute table contains columns for unique characterizations of surface water inundation dynamics (including measures of event frequency, duration, depth, and timing), yearly sums of the number of days a surface was inundated, and a classification of floodplain areas based on average annual duration values. All calculations summarize patterns occurring during 1 April through 30 September from 1972 to 2011. We excluded areas permanently wetted (aquatic areas), surfaces in agricultural production, roads, and developed areas. The data are intended for use in geospatial analyses of UMRS floodplain ecosystem patterns and processes.

密西西比河上游系统（Upper Mississippi River System, UMRS）中，漫滩淹水被认为是驱动一系列生态系统格局与过程的核心物理驱动因子。
本研究展示了一套地表水体连通性地理空间模型的分析结果，相关生态调查的完整细节已刊载于美国地质调查局（United States Geological Survey, USGS）公开文件报告《密西西比河上游系统生态系统结构与功能指标》（Indicators of Ecosystem Structure and Function for the Upper Mississippi River System）（De Jager等，待刊）。
简言之，本研究通过将水文站点监测得到的每日水面高程时间序列，与经坡度和水文汇流修正的地形-水深数据进行比对，识别出漫滩淹没的潜在区域。
最终生成的栅格属性表包含以下字段：地表水体淹水动态的唯一特征值（涵盖淹水事件的频次、持续时长、水深及发生时间等指标）、地表每年累计淹水天数，以及基于年均淹水时长划分的漫滩区域分类结果。
所有计算结果均汇总了1972年至2011年间每年4月1日至9月30日的淹水格局。
本研究排除了永久湿润区域（水生区域）、农业生产用地、道路及建成区。
本数据集可用于密西西比河上游系统漫滩生态系统格局与过程的地理空间分析。