2004 UC Proceedings Abstract
Estimating Drainage Areas Using Thiessen Catchments for the NHD Track: Water Resources Author(s): Alan Rea The National Hydrography Dataset (NHD) does not currently contain information relating to the landscape through which the stream network flows. The effort described in this presentation is an initial step to develop catchment areas and other characteristics for each NHD network segment. A catchment is defined here as the area that contributes overland flow to a stream segment. Thiessen catchments are defined based on distance to the nearest NHD stream and do not take terrain elevation information into consideration. Thus they provide only an approximation of the true catchment areas. Because this technique is computationally efficient, we can use Thiessen catchments with regression equations to quickly compute rough estimates of mean annual stream flows for millions of NHD drainage network segments nationwide. Alan Rea U.S. Geological Survey Idaho District 230 Collins Road Boise , ID 83702 US Phone: 208-387-1323 E-mail: ahrea@usgs.gov |
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