Questions tagged [watershed]

Use this tag when asking a question about a watershed related to GIS environment.

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128 views

Discrete waterpoints with GRASS [closed]

I've been working with GRASS GIS for about two months. I have to develop a method for the identification of target regions of small hydropower plants. Boundary conditions are a predetermined minimum ...
4
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1answer
1k views

Get drainage basin of a polygon (with QGIS, GRASS or other FOSS)

Using a polygon shapefile and a raster DEM, I'd like to find a way to get the drainage basin of a polygon area — that is, the area of all cells which drain into or through the cells contained in the ...
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1answer
202 views

Generate subcatchment starting from a DTM [duplicate]

I would like to know if there is a plug-in in Quantum GIS, which can help me to generate subcatchments starting from a DTM.
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0answers
108 views

How to create a boundary vector of objects after using watershed_segmentation python

I used watershed segmentation in opencv-python to separate object. However, after segmentation I don't know how to create boundary polygons of objects (red rounded in the image attached).
3
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4answers
19k views

How to calculate for every basin/sub-basin, drainage area at every elevation contour along stream?

With DEM as a source, I created all necessary files like flow direction, accumulation, slope, streams, watersheds, pour point etc... In my watershed (basin), I have many sub-watersheds (sub-basin) ...
2
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1answer
179 views

r.watershed basins at coast / ocean lines

I am using r.watershed to create watershed basins using a 25*25m dem. The problem I have is that basins are not always created at coast lines. I am experimenting with the parameter "minimum size of ...
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1answer
1k views

Arcgis 10.1 Archydro tools, converting RasterToPolygon How can I solve: ERROR 000732: Input Table:

I´m using arcgis 10.1 and Archydro tools. During the Catchment Polygon Processing, one of the steps used to define the watershed limits, I get the folowing error: Executing: CatchmentPolyProcessing ...
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1answer
475 views

What is the 'water retention capacity' tool and how is it used?

In the latest version of QGIS, I found a geoalgorithim in the processing toolbox that will generate 'water retention capacity.' I am familiar with DEM-based hydrologic modeling tools in QGIS, but I ...
3
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2answers
4k views

Python code to compare two fields in different feature layers?

I have two shapefiles which encompass 3897 features each. Corresponding shapefiles (village and watershed that flows into it) have the same ID (ws_id in one, OBJECTID in the other). Many watersheds ...
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2answers
231 views

Grass tools for watershed determination are not working well in QGIS

We have been using r.watershed QGIS-Grass tools for several months now without any problem, even with different QGIS versions. However, recently the tools are getting us results with a bigger pixel ...
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1answer
6k 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 get ...
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1answer
411 views

Calculating mean altitude of watershed for each cell of DEM?

I have a DEM of river basin, and I need to create a raster where the cell value will be the mean elevation of watershed of this cell. I have calculated watershed area (flow accumulation x cell area). ...
3
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1answer
950 views

How to interpolate raster data using computer vision (OpenCV)?

Background A raster file collected via LIDAR records the topography of a watershed. To properly model the watershed, the river must appear continuous without any breaks or interruptions. The roads in ...
2
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1answer
43 views

How do I know topo layer contains DEM-altitude? ArcMap 10.3

How do I know if a topographic layer contains DEM-altitude? ArcMap 10.3
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1answer
423 views

Automatically calculate average slope of a street segment

I'd like to be able to automatically calculate the average slope of a street segment in ArcMap (start elev - end elev / length). My map looks something like this, with street centerlines in black and ...
2
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2answers
847 views

What are the meaning of Grass drainage direction values from r.watershed

In Grass r.watershed the D8 drainage directions generated from r.watershed are -8. -6.-4.-2, 2, 4, 6, 8 (-1 No Data) What actual directions are these? For example in ArcGIS I know 128 is up and so ...
2
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0answers
79 views

Comparing areas of two raster files [closed]

I need to compare the areas of two rasters for calculating the percentage parts from another. For example, I have one raster file which shows separated agriculture fields. The value of each field is 1 ...
2
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2answers
766 views

Storm Water flooding [closed]

Is there a method in Arc Gis for mapping storm water runoff in an urban environment assuming that the sewers are at full capacity. I just want to map roughly where the water will flow over the land ...
1
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1answer
308 views

How to define pour points from a stream network at a barrier for watershed calculations?

I'm looking for a way to check if cells from one raster file have contact or get close to cells from a second raster file. For example the blue raster is a barrier and the coloured is the flow ...
0
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1answer
143 views

How to calculate stream order in GRASS 7.0.2?

I would like to calculate Strahler's and other stream hierarchy from my input raster but I am not sure how. This manual suggests tat I should use r.stream.order command, however in version 7.0.2 "...
1
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1answer
591 views

How to design a flood with water elevation on a specific point?

Actually I have to know the flooding area caused by a rise of the water level due to the implementation of a dam. So I would like to know if there is an extension or any tool in QGIS or GRASS which ...
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0answers
70 views

Ideal minimal area for watershed automatic delineation using DEM SRTM

I need to do a bunch of analysis on a city using for that, watersheds . As smaller the watersheds are, better are quality of my work. Due to the vertical accuracy of SRTM DEM, I know there are some ...
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0answers
1k views

Stream Order: Strahler vs Shreve

I am writing a research paper on watershed delineation and I am looking for experiences/opinions/authoritative answers on: What guides a hydrologist when it comes to choosing between Strahler's (1952)...
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1answer
480 views

Expression into the raster calculator to invert DEM

I've made a DEM from first pass LiDAR data which I want to invert and run watershed segmentation and basin delineation over in order to hopefully extract tree canopy outlines and heights - I'm newish ...
2
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0answers
322 views

Using “snap pour point” to find a watershed of specific area starting from a point [closed]

I am trying to find everything downhill of a certain point in order to create a watershed of a specific area. For example, say I have a point at (x,y), and I'm interested in creating a watershed ...
4
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0answers
698 views

Error when using r.watershed in QGIS 2.10.1 with Grass

I am running r.watershed within QGIS processing the I get the error below. I draw your attention to: GRASS_INFO_WARNING(2205,1): Subprocess failed with exit code 256 GRASS_INFO_END(2205,1) Does ...
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1answer
803 views

Calculating watershed using snap pour points?

I am trying to calculate a watershed layer and have followed instructions from this previous question: General steps to create watershed boundary in ArcGIS Spatial Analyst? I have combined all these ...
2
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0answers
101 views

GIS or Remote Sensing technique to map sub-surface features?

I am trying to delineate agriculture tile drainage in Midwest. Does anyone know of any GIS and/or sub-surface remote sensing techniques to detect tiles/objects buried in shallow depth of soil? Does ...
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0answers
241 views

Riparian corridor delineation in QGIS

I am trying to delineate the riparian corridors using GRASS in R. But I am having some issues. So is there a plugin in QGIS using which I can extract riparian corridors using the already available ...
3
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2answers
2k views

ArcPy script stops running randomly with no error returned

I am doing a batch watershed and analysis process on 135 points. This script worked great the first time I ran it. Ever since the first time, however, I have had the script stop at random moments. ...
4
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0answers
346 views

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 ...
4
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1answer
360 views

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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2answers
2k views

Understanding flow accumulation

I used this youtube video: https://www.youtube.com/watch?v=FSblORbDyhc&list=PLWJ2X2wvq78QRGzl8Un5ADF0_4m5t99iD&index=11 to learn how to run flow accumulation and was successful. I realize it ...
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0answers
49 views

grass r.watershed to larger rivers parallel lines to same stretch

I'm trying create stream channels with r.watershed grass64. However, it shows two or three parallel lines for the same stretch of river. The river is large in some parts, but is just one river. Does ...
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0answers
596 views

Combining Raster and Vector data

I've created a Watershed raster data set (using the Watershed Tool) for a certain area. Within that watershed raster, there are 8 basins that appear I'm trying add the total population to each of ...
2
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2answers
1k views

How to create a reservoir for a dam site?

I have created the watershed for a proposed dam site point using SRTM 90m DEM. Now my task is to create a reservoir or pondage where water would be collected from the watershed. Above a watershed can ...
10
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4answers
4k views

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 ...
0
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2answers
648 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 ...
3
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0answers
238 views

Preventing flow accumulation in one watershed from traveling up tributaries into adjacent watersheds?

I am using TauDEM in ArcMap 10.3.1 to try and calculate flow accumulation and generate stream networks for HUC10 watersheds. I am using 3m DEMs acquired from the National Map. The HUC10 I am working ...
2
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0answers
655 views

Delineate watershed using manual points in RSAGA

I'm currently trying for an automated solution to delineate watersheds within a large basin. I have a collection of locations (X,Y coords) for various tributaries reaching a larger river, and the end-...
8
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1answer
8k views

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 ...
4
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1answer
153 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 ...
4
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1answer
6k views

Water Flow Analysis in ArcGIS Desktop?

If I know that 10,000+ gallons of water were going to be dropped at a single point how could I model where it would flow. I would prefer something that worked in ArcGIS and could create a layer.
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2answers
1k views

How to find the watershed for each outlet point and sum values within it?

I have the following files to work with: Stream network of a basin; Outlet points for each segment* of the network and Points which represent water withdrawals along of the stream, which are not ...
2
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1answer
45 views

Is there a way to automatically find errors made by the Watershed tool?

I've delineated the watershed of near 7000 reservoirs with the Watershed tool in ArcGIS 10.1 and converted them in polygons. As you can see in the image bellow, some mistakes were made because the ...
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1answer
1k views

Is there a method to create watershed on google earth?

I want to create a watershed boundary for a lake only using google earth without using other source of data like srtm etc. Since we get the height of the location can we use it somehow and create a ...
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0answers
400 views

Simulate water runoff to get water height over each pixel of DEM

Here is my problem that I am trying to deal with. I have given a height map of around 512X512 resolution(It is Geo-referenced and I have the meta-data for this). And I have given that this area ...
2
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1answer
851 views

Hydrology tool dataset in ArcGIS 10.1 for calculating slope?

I am quite new to the hydrology toolset in ArcGIS and thought it may be useful for extracting slope data from a raster. I was wondering if anyone had experience trying to extract slope data upslope ...
5
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1answer
521 views

Does this ArcGIS flow accumulation example have an error?

The lower right corner of the flow accumulation example in ArcGIS Desktop's documentation has a flow accumulation value of 2. However, I only see one cell flowing into the lower right corner (the ...
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2answers
6k views

How to determine drainage area upstream from point?

I do not know how to come up with the drainage area (km squared) upstream of Lat 77.84, Long -30.96. I have converted my contour shapefile to a raster, identified and filled the sinks and then created ...