Model Archive of the flood-inundation maps for North Fork Salt Creek at Nashville, Indiana

Digital flood-inundation maps for a 3.4-mile reach of North Fork Salt Creek at Nashville, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage 03371650, North Fork Salt Creek at Nashville, Ind. Real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/nwis or the National Weather Service (NWS) Advanced Hydrologic Prediction Service at http:/water.weather.gov/ahps/ (NWS site NFSI3). Flood profiles were computed for the stream reach by means of a one-dimensional, step-backwater hydraulic modeling software developed by the U.S. Army Corps of Engineers. The hydraulic model was calibrated using the current stage-discharge rating at the USGS streamgage 03371650, North Fork Salt Creek at Nashville, Ind. The hydraulic model was then used to compute 12 water-surface profiles for flood stages at 1-foot (ft) intervals, except for the highest profile of 22.9 ft, referenced to the streamgage datum ranging from 12.0 ft (the NWS “action stage”) to 22.9 ft, which is the highest stage of the current USGS stage-discharge rating curve and 1.9 ft higher than the NWS “major flood stage.” The simulated water-surface profiles were then combined with a Geographic Information System digital elevation model (derived from light detection and ranging [lidar] data having a 0.98-foot vertical accuracy and 4.9-foot horizontal resolution) to delineate the area flooded at each stage. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage, will provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts. The associated data files in this data record are the input and output files for the U.S. Army Corps of Engineers HEC-RAS model used to create the flood-inundation maps for the documented report. Dataset is a model archive containing all relevant files to document and re-run the models that are discussed in the cited U.S. Geological Survey Scientific Investigations Report.

美国地质调查局（U.S. Geological Survey, USGS）与印第安纳州交通运输部合作，针对印第安纳州纳什维尔境内北叉盐溪3.4英里河段制作了数字洪水淹没图。该洪水淹没图可通过美国地质调查局洪水淹没制图科学网站（http://water.usgs.gov/osw/flood_inundation/）获取，其展示了对应印第安纳州纳什维尔北叉盐溪USGS水文测站（streamgage）03371650选定水位的洪水范围与水深估算结果。该水文测站的实时水位数据可从美国地质调查局国家水信息系统（http://waterdata.usgs.gov/nwis）或国家气象局（National Weather Service, NWS）水文预报高级服务（Advanced Hydrologic Prediction Service, AHPS）网站（NWS站点NFSI3，网址http://water.weather.gov/ahps/）获取。研究人员采用美国陆军工程兵团开发的一维回水演算水力学模型软件，对该河段的洪水演进过程进行了模拟计算。本次水力学模型采用印第安纳州纳什维尔北叉盐溪USGS水文测站03371650的最新水位流量关系曲线（stage-discharge rating）进行了率定。基于该率定后的模型，研究人员针对以测站基准面为参照的洪水水位值，按1英尺（ft）间隔计算了11条水面线，另补充最高水位线22.9英尺，整体水位区间从12.0英尺（对应国家气象局“警戒水位”）至22.9英尺。其中22.9英尺为当前美国地质调查局水位流量关系曲线的最高水位值，较国家气象局“重大洪水水位”高出1.9英尺。随后研究人员将模拟得到的水面线与地理信息系统（Geographic Information System, GIS）数字高程模型（基于垂直精度0.98英尺、水平分辨率4.9英尺的激光雷达（light detection and ranging, lidar）数据生成）相结合，以此划定各对应水位下的淹没区域。此类地图的可获取性，搭配美国地质调查局水文测站发布的实时水位网络信息，可为应急管理人员与当地居民提供关键信息，用于洪水应对工作（如疏散与道路封闭）以及灾后恢复工作。本次数据集记录中的关联数据文件，为用于制作该研究报告中洪水淹没图的美国陆军工程兵团HEC-RAS模型的输入与输出文件。本数据集为模型归档文件，包含了所引用的美国地质调查局科学调查报告中提及的所有用于记录并复现模型的相关文件。