Generovat toky z DEM

Question

<\/HEAD>Zde je nějaké pozadí. Snažím se vytvořit toky z DEM. Data DEM jsou produkt LiDAR, s rozlišením 1 metr. Exportoval jsem malou oblast provincie. Počet rastrových buněk = 1200 milionů. Provedl jsem hydrokondicionování DEM, Fill a Flow Direction. Vše bylo úspěšně dokončeno v rozumném čase. Ale Flow Accumulation trvalo 40 hodin, než se dokončilo.<\/SPAN><\/P> <\/SPAN><\/P>Sledoval jsem online video o ArcHydro. Prezentující řekl, že nástroje lze spustit na jakoukoli velikost dat od povodí až po celý stát nebo dokonce zemi. Chci vědět, jak byste spustili nástroj Flow Accumulation pro stát, v mém případě provincii. <\/SPAN><\/P><\/BODY><\/HTML>

ArthurCrawford01 · Answer

Another option would be the tools from the Center for Research in Water Resources.   I have used their Optimized Pit Removal to quickly process data to then get streams for large areas.    I used this tool to extract streams for the continent of Africa from SRTM data and was recommended to me by one of our hydrology experts.

Link: tools.crwr

Optimized Pit Removal

Contains ArcGIS (version 10.1) geoprocessing script tools for removing pits (or sinks) from Digital Elevation Models using a combination of cut and fill. This alternative to the standard Fill tool provides more realistic flow paths with less required manual adjustment. Ideal for high-resolution datasets such as LiDAR.

Arthur Crawford - Esri

DanPatterson_Retired · Answer

You had better reduce the extent to what you actually need,  or reduce the cell size.  A doubling of the cell size will reduce the raster to 1/4 of its original size.  Do you really need 1 m resolution for a flow accumulation?  Is the input data that accurate? I would suggest that you would see better results if you to a reasonable cell size.  Report the number of rows and columns that you have so further advice can be provided.

ClarkLangridge · Answer

Yes, same cell size as the 1 metre.