Description: HYDROGRAPHY_BANK_FULL_WIDTH_NHD_IN was prepared to support the Indiana Fluvial Erosion Hazard (FEH) Mitigation Program. The FEH program is focused primarily on erosion that occurs due to the lateral movement of streams. The process of moving across a valley bottom is characteristic of alluvial streams, or streams that build floodplains. As these streams move, or meander across the valley bottom they erode and deposit sediment in a series of alternating cutbanks and pointbars. If a stream is given the room that it needs to make the lateral adjustments that are required by fluctuations in stream flow and sediment supply, most erosion hazards can be avoided. A fundamental concept within the field of fluvial geomorphology states that, as one moves downstream within a watershed, there is a predictable and quantifiable rate of increase in bank full-channel dimensions.The USGS and CEES collected data at 82 study sites to identify bankfull stage, determine the dimensions of bankfull width, mean depth, and cross-sectional area, and document channel geometry characteristics that allow for determinations of channel classification. From these data, regional channel-dimension equations were developed for the three largest physiographic regions of Indiana—the Northern Moraine and Lake region, Central Till Plain region, and Southern Hills and Lowlands region. GIS analyses used these equations to calculate avoidance zones based on bank full width. The tools and details of the FEH program can be found at http://feh.iupui.edu/For Mobile and Non-Mobile streams, a GIS analysis algorithm generated bankfull width values for each stream segment based on drainage area within the physiographic region. The analysis also used these values to create buffer zones of at least 100 feet or 3X bankfull width. For Mobile streams GIS generated an 8X bankfull width buffer which was manually edited and adjusted to reflect the digital elevation model and stream meander evidence.
Service Item Id: 52b3862f4c8449a18fad1f325b17e6bb
Copyright Text: Acknowledgment of the Indiana Silver Jackets would be appreciated in products derived from these data. It is also requested that the Indiana Silver Jackets be cited in any products generated from this data set