Tag Info

I did! =) Watershed command are working right now. I regenerate outlet points and I could get the correct pour points. In other hand, I followed another method. Instead using Zonal Statistics, I did iteratively for each outlet point as follows: Generate watershed [watershed]; Select withdrawals within the watershed [select by location]; If the count of ...

ESRI has a good support section on hydrologic analysis. Also, there is a pretty good video tutorial here on how to create drainage networks in ArcMap. The attached image from ESRI shows a stream network created using ArcMap's hydrologic tools and a digital elevation model (DEM) available from USGS Earth Explorer.

The solution to your problem may be to use Infrastructure Network Editing, specifically the Flow Accumulation tool on the Infrastructure Reporting Toolbar. You'll need at least a Standard (Editor) license to build a geometric network. You'll also need to specify a weight. At each point or line, Calculate Accumulation will add up all your upstream weights ...

Assuming that each withdrawal point is related to the closest stream segment, we can do the following: Use the split line at point tool to split the stream line into segments based on outlet points (depending on your data you may already have this). Make sure that each point has an ID, which should relate to stream order (see one method below for an ...

Have you tried to create a mosaic out of the rasters and doing one watershed computation? This link is helpful for raster mosaics in qgis. Trying to make separate basins and putting them together probably won't work due to edge contamination.

You can calculate Flow Length from a Flow Direction raster, but you need your original DEM to do that. Your watersheds are just "areas that drain into a point" and don't retain the necessary flow direction information. Since your stream gauge is in the middle of the larger watershed, calculate the downstream flow length and then use the identify tool (or ...

The default for the watershed tool is to limit the output extent to the same as your input pour points. You can change this in the Output Extent (Environment setting) to the maximum of inputs or same as the original DEM. For more info see The analysis environment of Spatial Analyst. Try the Snap Pour Point tool to see if this helps ensure that your crater ...

You will definitely need an elevation raster (DEM) to do what you want. With the DEM you can use two GRASS modules to get individual drainage areas for points along the river network as follows: First calculate a flow direction grid from the DEM with r.watershed: r.watershed elev=DEM thresh=<your threshold> drain=flow_dir_grid See the r.watershed ...

You will need to define your lakes as sinks (Create sink structures), and then use the ArcHydro function Adjust flow in lakes/streams/sinks. (These functions are only available in ArcHydro for ArcGIS 10.1, I have made a function that, with some modifications, might help you on the way if you are in 10.0.) You can also erase (Extract by mask) the lakes from ...

If by Basin Length, you mean the maximum distance from the watershed boundary to the pour point, you need to use the Hydrology tools from the Spatial Analyst Toolbox. First fill the sinks of your DEM using the Fill Tool. Then calculate the Flow Direction, using the Flow Direction Tool Finally Use the Flow Length Tool. The value of the output at the pour ...

Are you talking about a line or a polygon? You could go to the attribute table and then right-click on top of a column and select 'calculate geometry' (or something similar unfortunately I can't access ArcMap at the moment to check this). In the pop-up you can select length, I believe. Hope this helps.

There are a number of stages required to get the required output, all of the tools are well documented in the arcgis online help and the page on stream ordering is very useful. The first stage in any hydrology processing is to fill any pits in the DEM using the fill tool to ensure that water can flow over the surface without becoming 'stuck' in an erroneous ...

The areas you are looking to create are called "subwatersheds" or subsheds. You can use the "Batch Subwatershed Delineation" tool in ArcHydro under the "Watershed Processing" menu. This will calculate subsheds from a set of points you define. The other input is a flow direction grid. This is a raster where the value of each pixel represents the direction ...