| snippet:
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NMFS West Coast Region leverages the National Hydrography Dataset (NHD) as a base dataset for managing marine and anadromous species. This NHD version was downloaded from the United States Geological Survey site in July 2012, merged across the Pacific Northwest and California, joined with the Value Added Attributes (VAAs), and queried by stream order. |
| summary:
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NMFS West Coast Region leverages the National Hydrography Dataset (NHD) as a base dataset for managing marine and anadromous species. This NHD version was downloaded from the United States Geological Survey site in July 2012, merged across the Pacific Northwest and California, joined with the Value Added Attributes (VAAs), and queried by stream order. |
| extent:
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[[-124.724439372571,32.5101731335523],[-109.770569888396,49.0393772609199]] |
| accessInformation:
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United States Geological Survey (USGS) |
| thumbnail:
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thumbnail/thumbnail.png |
| maxScale:
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1.7976931348623157E308 |
| typeKeywords:
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["Data","Service","Map Service","ArcGIS Server"] |
| description:
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<DIV STYLE="text-align:Left;font-size:12pt"><DIV><DIV><P><SPAN>NMFS West Coast Region leverages the National Hydrography Dataset (NHD) as a base dataset for managing marine and anadromous species. The symbology within this map service is broken down by stream order. Stream order (calculated in the NHD using Strahler Stream Order (Strahler, A.N., 1952; Horton, R.E., 1945)) in hydrography deals with the hierarchy of streams from the source (or headwaters) downstream. The headwaters are the first order and downstream segments are defined at confluences (two streams running into each other). At a confluence, if the two streams are not the same order then the highest numbered order is maintained on the downstream segment. At a confluence of two streams with the same order, the downstream segment gets the next highest numbered order. Divergences such as braided streams actually maintain the same order all the way through the braid, just like it was a single stream; however, divergences that are not braided streams keep the upstream order number and follow the normal hierarchy further downstream. </SPAN></P><P><SPAN>Horton, R. E. (1945), "Erosional development of streams and their drainage basins: hydro-physical approach to quantitative morphology", Geological Society of America Bulletin 56 (3): 275–370. </SPAN></P><P><SPAN>Strahler, A. N. (1952), "Hypsometric (area-altitude) analysis of erosional topology", Geological Society of America Bulletin 63 (11): 1117–1142. </SPAN></P><P><SPAN>More info on Strahler stream order: https://usgs-mrs.cr.usgs.gov/NHDHelp/WebHelp/NHD_Help/Introduction_to_the_NHD/Feature_Attribution/Stream_Order.htm</SPAN></P></DIV></DIV></DIV> |
| licenseInfo:
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>Refer to the United States Geological Survey for source data.</SPAN></P></DIV></DIV></DIV> |
| catalogPath:
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|
| title:
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National Hydrography Dataset |
| type:
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Map Service |
| url:
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|
| tags:
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["National Hydrography Dataset","NHD","rivers","streams","creeks","flowline","waterbody","stream order","Strahler"] |
| culture:
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en-US |
| name:
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National_Hydrography_Dataset |
| guid:
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49720D30-0175-4C88-8600-2621DB3DC4C3 |
| minScale:
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0 |
| spatialReference:
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WGS_1984_Web_Mercator_Auxiliary_Sphere |