Description: This GIS layer was prepared to support the Indiana Fluvial ErosionHazard (FEH)Mitigation Program.The FEH program is focusedprimarily on erosion that occurs due to the lateral movement of streams.The process of moving across a valley bottomis 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 alternatingcut banks and point bars.If astream is given the room that it needs to make the lateral adjustments that are required by fluctuations in stream flowand sediment supply, most erosionhazards can be avoided. A fundamental concept within the field of fluvial geomorphology states that, as one moves downstream within a watershed, there is apredictable and quantifiable rateof increasein bank full-channel dimensions.The USGS andCEES collected data at 82 study sites to identify bank full stage, determine the dimensions of bank full 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 developedfor the three largest physiographic regions of Indiana — the Northern Moraine and Lake region, Central TillPlainregion, and Southern Hills andLowlands region. GIS analyses used these equations to calculate avoidance zones based onbankfull width.The tools and details of the FEH program can be found at http://feh.iupui.edu/For Actively Migrating and Relatively Stationary 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 Relatively Stationary Stream and for Actively Migrating streams GIS generated an 8X bankfull width buffer. If the resulting boundary was manually edited and adjusted to reflect the digital elevation model and stream meander evidence it would receive the attribute RCW, which stands for Refined Corridor Width. The mapped FEH zones can be identified by the folloiwng attributesFEH_Type - FEH_Zone - DescriptionACTIVELY MIGRATING - RCW_8X - This indicates that the 8 times buffer of BFW was used and manually modified.ACTIVELY MIGRATING - 8X - This indicates that only the 8 times buffer of BFW was used.RELATIVELY STATIONARY - 3X_100 - This indicates that either the 3 times BFW or 100 foot buffer was used.RELATIVELY STATIONARY - RCW_3X_100 - This indicates that either the 3 times BFW or 100 foot buffer was used and manually modified.POTENTIAL INSTABILITY - <NULL> - This boundary was created based on surface geology, land forms, and hydrologic features to identify areas of potential erosion.
Service Item Id: 8467c864e5be4f53ab861319e1302276
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