Method and apparatus for deriving stream network vectors from digital elevation map data

摘要

A processor-based apparatus for computing stream vectors for an area of interest divides the area of interest into a number of hydrologic unit code (HUC) areas. The processor calculates stream vectors from lower resolution digital elevation map (DEM) data. For those HUC areas where higher resolution DEM data is available, the processor merges the lower resolution and higher resolution DEM data. Stream vectors are calculated from the merged DEM data and used to replace those stream vectors calculated from the lower resolution DEM data. Attributes of stream vectors that receive upstream flow from an adjacent HUC area are corrected.

主权项

1. A processor-based system for calculating stream vectors in an area of interest, comprising:
a memory for storing program instructions; processor electronics configured to execute the program instructions in order to:
receive digital elevation map (DEM) data for a number of hydrologic unit code (HUC) areas having lower resolution digital elevation map (DEM) data and for which at least one HUC area has both lower resolution and higher resolution DEM data available;compute a number of stream vectors for the HUC areas that define the area of interest from the lower resolution DEM data;where higher resolution DEM data in a HUC are available:
merge the lower and higher resolution DEM data for the HUC;compute a number of stream vectors from the merged DEM data;replace the stream vectors for the HUC area that were computed from the lower resolution DEM data with the stream vectors computed from the merged DEM data;mark pour points where flow enters the HUC area from one or more surrounding HUC areas outside of the HUC area that is covered by the merged DEM data;correct attributes of the stream vectors computed from the merged DEM data that are downstream of the pour points by
modifying the lower resolution DEM data to include corrected locations of the stream vectors computed from the merged DEM data;recalculating stream vectors and their attributes for the HUC area and those surrounding HUC areas that supply inflow to the HUC area using the modified lower resolution DEM data; andreplacing attributes that were incorrectly determined from the merged DEM data with the attributes determined from the modified lower resolution DEM data.