A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place.

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Calculate line distances inside of polygons using ArcGIS for Desktop?

I'm working with two data sets: NHD polyline stream layer for my entire state HUC Watershed boundary Polygons for the entire state I am looking for a way to calculate the total length of streams ...
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How to assign correct flow direction to stream network polylines?

I would like to create a map showing the results of watershed analysis as well as the resulting stream network with flow direction. I have a stream network which has been created from the flow ...
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3k views

How to use GRASS module to delineate watershed area?

Update#1:I changed to work under qgis 1.8, I only input the DEM file and run the r.watershed module, and I got this: I have a DEM file of one specified region, and I take the following steps to ...
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What Algorithm is used by ArcGIS Watershed tool?

Does anyone know what type of algorithm is used in the ArcGIS Watershed tool (in the Spatial Analyst package)? Very little information given on Esri's website ... but I suspect it may be some kind of ...
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Different watersheds for same area because of “burned streams”

Im trying to analyse where water is flowing which rains down to my project area. This is the DEM I have (my project area is bordered blue, the red marks are my pour points): I learned from another ...
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How to indicate flow of a watershed feature?

While tracing and digitizing rivers, streams, rivulets, etc., is it possible to indicate the direction/flow in the shapefile on QGIS? I'd like to avoid using map labels. Ideally, when done tracing, I ...
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227 views

Watershed layers with names for each one for Europe or Sweden?

I am working on freshwater species and I would like, make a list of each watersheds used for each species. So I am looking for a watershed maps which contain name of the watershed. I found some good ...
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General steps to create watershed boundary

I am a very beginner of ArcGIS. I got this CD of GIS files of a city and intend to work on watershed management. There are different file names in different formats on CD. Like .shp, .shx, .dbf, ...
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How to find the watershed area for each point in the river network using DEM?

Update#1: Thanks, Micha, I have followed your instruction and successfully use the modules in GRASS. I use r.watershed to get the basin raster and the drainage line: and I use r.water.outlet to get ...
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142 views

How to separate shared watersheds?

I put a pourpoint at the end of a headwater stream, then another further downstream that is fed by that headwater stream plus two others. Obviously the pourpoint further downstream is going to share ...
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660 views

When computing flow direction, the D8 algorithm is used - are there major differences if others are used?

I am a student working with Hydrological models. Within these models we can route water across a DEM (within a delineated watershed or just within an un-delineated DEM) using many different flow ...
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750 views

Watershed extraction using different DEM tiles

I would like to extract the watersheds for a particular area using QGIS. However, I only have Aster 30m DEMs to work with, each tile covering one degree square. The problem is that I need to use ...
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Could bridges prevent ArcMap from creating correct watersheds?

I have a very detailed DEM of a region in Northern Germany. For hours I tried creating correct watersheds but my results all look illogical. Is it possible that bridges disturb the ArcMap Tools? I ...
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What are definitions of watershed segmentation, local maxima, variable window search, regarding LiDAR for vegetation?

I am not familiar about Lidar. I want to measure trees height and number of trees. I guess, watershed = to locate the trees, local maxima = to measure trees height. I used these methods in SAGA GIS. ...
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1answer
55 views

Watershed Tool Straight Edge Problem

I'm trying to accurately delineate a watershed into sub-basins using dams as pour points. I'm using the hydrology toolset, but I can't seem to get rid of straight edges that are along some of the ...
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How to do the loop when using GRASS module r.water.outlet?

I have seen this post:Watershed Analysis with GRASS, and I have a .txt file which contains coordinates of many points, and I want to use r.water.outlet to get basin area of each point. I type the ...
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868 views

Calculating watershed runoff with landuse and rainfall data?

What is the method for computing rasters of total rainfall of a given month, flow accumulation, and land use (runoff coefficient) or soil K factor? I am using ArcMap 10.
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Python code to select streamlines within selected watershed

I'm trying to calculate total stream length for multiple, overlapping watersheds (i.e., each watershed contains the watersheds upstream of it). I have a flowline layer that I've run through the ...