Questions tagged [flow-accumulation]
In hydrological modelling, flow accumulation shows water collection based on flow direction. Flow accumulation is used to generate a drainage network
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Which library to use for calculating flow accumulation from DEM raster?
I have acquired the DEM raster for a watershed area. I want to first calculate the flow accumulation using D8(Deterministic 8-Node) algorithm. Earlier in our lab people have used GRASS in Python to ...
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WhiteBoxTools drainage lines will not terminate at coast
I want to generate drainage lines for a country (Mexico in this case) and have a DEM and country border. I masked the DEM at the border (set raster cells to nodata outside the Mexico region) and ran ...
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Visualising accumulation of point source pollution pressures downstream
I am trying to visualise accumulation of point-source pollution risk in a river network. I have a vector layer river network, and a separate network which has flow pathways, direction, and basins ...
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Accumulate upstream attributes on a stream for a limited number of upstream segments or limited distance from the sample point
I have over 10,000 points on stream line segments in a network, where each point corresponds to one line segment. I'd like to average an attribute (shade) for the four upstream points from each point, ...
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Delineating watersheds for thousands of polygons
I have a data layer that shows a few thousand polygons that represent areas for potential wetland restoration based on a variety of criteria (soil type, on certain types of land cover, etc).
For each ...
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R terra Flow Accumulation resulting raster with DN = 1
I encountered problems in calculating flow accumulation using terra::flowAccumulation() from lidar-based DEM. I've inspected the visual and general properties of the DEM and flow direction rasters, ...
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Which algorithm is executed by FlowAccumulationFullWorkflow in Whitebox Tools?
Whitebox Toolset for Hyrdological Analysis offers many different flow accumulation algorithms, like D8, DInf, MdInf, Qin, Quinn, and Rho8. It also has the FlowAccumulationFullWorkflow tool, which ...
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QGIS: Flow Accumulation Tool not progressing past 100%
I'm trying to do run the flow accumulation tool on a map where I am trying to extract drainage from a DEM however it has been stuck at 100% for several hours. I have put details of the files I am ...
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Calculating flow path length in R
I am currently trying to calculate the flow path length in a DEM towards a streamnetwork. My desired outcome would be a raster with values of how long the flowpath to the nearest streamcell would be ...
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Looking for an automated method for headwater watershed delineation at county scale
I am hoping to delineate watersheds, which are extremely small, across a large area.
My objective is to create a workflow that will delineate all head water catchments through an automated process. I ...
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Python library for hydrology calculations for multiple points
I have a DEM (TIFF) with multiple points, which mark wells (right term?) of an underground pipe network:
I was wondering if there is a Python library which uses the elevation of the DEM to generate a ...
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Issues with vectorisation of thinned flow accumulation through r.to.vect on QGIS
I'm trying to produce a shapefile river network from a flow accumulation raster using the r.to.vect function and I've overcome some difficulties regarding bit depth and thinned raster.
n.b. I don't ...
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Problem with r.fill.dir on merged raster layer
I am going to use r.fill.dir on an area. The downloaded data comes as a set of tiles that puzzle together.
In order to delineate watershed across tiles I need to merge them to a complete raster.
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Weighting the flow accumulation raster by the slope raster in QGIS
I am trying to represent de equation of Mahoney et al. (2018)
https://www.sciencedirect.com/science/article/abs/pii/S0022169418302877
Where Si is the slope in the cell i, ΣSup is is the sum of the ...
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QGIS Flow accumulation tool frozen at 100%
My goal is to apply a topographic wetness index to a DEM using QGIS Version 3.20.2-Odense, running on a macOS laptop. I have clipped my DEM layer for the appropriate study area, and calculated slope ...
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