topic HEC GeoHMS Terrain Processing - NHD Flowline vs USGS Elevation Data Quality in Water Resources Questions https://community.esri.com/t5/water-resources-questions/hec-geohms-terrain-processing-nhd-flowline-vs-usgs/m-p/513801#M2635 <HTML><HEAD></HEAD><BODY><SPAN>Hi, </SPAN><BR /><BR /><SPAN>I'm trying to decide if I should apply the burn-in process as part of terrain preprocessing per the HEC GeoHMS user manual. I've read that when deciding to apply the burning-in process implies that flowline data are more reiliable than the DEM data. </SPAN><BR /><BR /><SPAN>So my question is, how should I go about determining if my NHD flowline data are 'better' than my USGS elevation data? What would be some key determining factors here? </SPAN><BR /><BR /><SPAN>A second and related question would be: what is an acceptable discrepancy between streams found using elevation data (w/ and w/out burning-in the flowline data) and actual locations? </SPAN><BR /><BR /><SPAN>Thanks in advance for any thoughts on this!</SPAN></BODY></HTML> Sun, 07 Nov 2010 00:24:48 GMT MichaelBrady 2010-11-07T00:24:48Z HEC GeoHMS Terrain Processing - NHD Flowline vs USGS Elevation Data Quality https://community.esri.com/t5/water-resources-questions/hec-geohms-terrain-processing-nhd-flowline-vs-usgs/m-p/513801#M2635 <HTML><HEAD></HEAD><BODY><SPAN>Hi, </SPAN><BR /><BR /><SPAN>I'm trying to decide if I should apply the burn-in process as part of terrain preprocessing per the HEC GeoHMS user manual. I've read that when deciding to apply the burning-in process implies that flowline data are more reiliable than the DEM data. </SPAN><BR /><BR /><SPAN>So my question is, how should I go about determining if my NHD flowline data are 'better' than my USGS elevation data? What would be some key determining factors here? </SPAN><BR /><BR /><SPAN>A second and related question would be: what is an acceptable discrepancy between streams found using elevation data (w/ and w/out burning-in the flowline data) and actual locations? </SPAN><BR /><BR /><SPAN>Thanks in advance for any thoughts on this!</SPAN></BODY></HTML> Sun, 07 Nov 2010 00:24:48 GMT https://community.esri.com/t5/water-resources-questions/hec-geohms-terrain-processing-nhd-flowline-vs-usgs/m-p/513801#M2635 MichaelBrady 2010-11-07T00:24:48Z