Questions tagged [hydrography]
Not to be confused with hydrology, hydrography describes the spatiotemporal distribution of water bodies and their features.
8 questions
27
votes
1
answer
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Calculating Flow Direction and Delineating Basins from Projected vs. Unprojected DEM Data [closed]
This is somewhat of a theoretical question stemming from some discussions with colleagues on the topic of implications with delineating basins with projected (e.g., Albers Equal Area) vs. unprojected (...
- 1,127
10
votes
3
answers
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Workflow for determining stream gradient?
As far as data goes, I'm working with NHD .shp files, 10m DEMs, and some LIDAR data.
My goal is to determine gradient for 100m segments of a network of streams.
I'm already able to do this, but I ...
- 930
15
votes
6
answers
26k
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Burning stream network into DEM layer using ArcGIS Desktop?
I am working on a DEM that in an area where there is little relief.
I would like to 'burn' the river network into the DEM so I can calculate flow accumulation and flow length accurately.
I am ...
- 151
7
votes
2
answers
10k
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Correctly merging DEM rasters and eliminating edge effects
I'm using 10m DEM rasters from the NRCS Data Gateway for a large portion of California. The problem is some strange tiling that appears after merging, but isn't present in the original data (before ...
- 143
7
votes
1
answer
1k
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Is there a way to get the percentage of different landuse types upstream of a given point?
I'm a fairly novice GIS user and know just enough to get in trouble in a lot of cases. I am trying to look at the connection between several measured parameters at a few hundred stations along ...
- 171
4
votes
1
answer
4k
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Stream Gradient - two types - using NHD high resolution data
I need to calculate slope, or stream gradient, two different ways:
Main channel slope from the pour point to the head/source point along the vector stream network
a local slope consisting of 100 ...
- 1,127
4
votes
1
answer
2k
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Processing time using ArcGIS Hydrology toolbox tools in standalone Python script vs ArcCatalog?
My question is: what might cause the ArcGIS 9.3 Hydrology Toolbox Snap Pour Point and Watershed tools to run significantly slower in a
Python script versus manually running the tools in ArcCatalog (...
- 1,127
1
vote
1
answer
818
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Removing disconnected cells in a stream network raster using ArcGIS
I've got a predicted stream network raster with cells values 0 (not a stream) and 1 (is a stream). My end goal is to create a network of connected polylines, but unfortunately there are some areas ...
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