Questions tagged [hydrology]

The study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability.

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3
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1answer
190 views

Apply volumes to points on a raster DEM in QGIS

I am trying to create a flood inundation map in QGIS from known flood volumes at specific points across a raster DEM. I could potentially do this manually for each individual point using contours ...
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1answer
134 views

Identify main inlet of a lake in ArcGIS

I'm trying to figure out an automated way to identify mountainslopes from where a rockfall could hit lakes using the hydrological tools of ArcGIS 10.7. As rockfalls do not behave like runoff water, ...
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86 views

Urban runoff volume calculation

I was wondering if someone could help me out on how to calculate runoff volume within an urban area ? I have already produced different outputs: Filled DEM Catchment area Channel network flow ...
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4answers
352 views

Seeking free software for rain catchment area?

I want to be able to calculate the catchment area that would feed rainwater into proposed swales. I can do this easily enough, and with sufficient accuracy--not much accuracy is really needed, on a ...
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2answers
116 views

Fill a sink with a known volume of water to obtain actual depth and extent of a pond

Using ArcMap 10.7 I have a raster with sinks in a terrain that I developed by processing a DEM dataset. Each sink has been delimited and turned into a polygon too, and its total volume was ...
2
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1answer
162 views

Creating flood inundation map from watermark QGIS

I have a high water elevation for a location and I want to subtract this elevation by the DEM raster to achieve a water depth raster, and I am not sure how to go about this. I am assuming a constant ...
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1answer
82 views

Population in upstream area (looping over FeatureCollection)

I want to calculate the sum of the population living in the upstream area of stations using the hydro package by gena. I think I will have to loop over the stations (using the identifier "GEMS_Stati")....
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1answer
85 views

Changing lakebed symbology to relative depth in ArcGIS 10.5 (TIN or raster file)

I have several TIN files representing empty lakebeds at altitudes ranging from 5000m to 3000m. I have calculated the TINs using ArcGIS hydrology tools and an ASTER v3 DEM projected to ...
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1answer
120 views

Calculating volume of several TINs in ArcGIS Desktop

I am trying to calculate the volume of several TINs using the 3D Analyst of ArcGIS 10.5. My data can be found here: https://drive.google.com/open?id=1ERFdsqDGLH1a_FbxwawE_gPm0Au0Q9vT For a start, I ...
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0answers
50 views

Calculating the volume of multiple lakes with ArcGIS (3D Analyst)

I have the DEM of a glacier bed and want to calculate the volume of bed depressions that could form lakes. Data is available here: https://drive.google.com/open?id=1ERFdsqDGLH1a_FbxwawE_gPm0Au0Q9vT I'...
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0answers
45 views

Using ArcGIS to quantify sink volume in glacier bed ("sink" and "fill" tools)

I am trying to identify sinks/overdeepenings in glacier beds and quantify their volume. If you take a look at my data (https://drive.google.com/drive/folders/1ERFdsqDGLH1a_FbxwawE_gPm0Au0Q9vT?usp=...
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0answers
227 views

Calculating drainage density

How can I calculate drainage density in QGIS if I have length for stream and grid line 1 km2? I need to calculate density per km2.
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0answers
72 views

Create catchments/subbasins for specific nodes

I have an XPSWMM model of a neighborhood storm drainage system. Nearly all of the drainage is above ground through a network of ditches and culverts. I still need to create catchments for the ...
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0answers
314 views

Vector map (rivers) to Raster. [ **ERROR 1: Wrong value for -outsize parameter.**]

I want to transform this vector map: To something like this I only tried to convert the vector map through Raster> Conversion> Rasterize But I get this Error: QGIS version: 3.6.3-Noosa QGIS code ...
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1answer
169 views

Quicker function than dissolve and difference

I'm on QGIS (v. 3.6) trying to create a map of Florida's hydrography using the NHD "Water Areas" shapefile. Methodology is to fix any invalid geometries in the NHD data, dissolve the layer, and then ...
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0answers
167 views

Extract longest flow path in ArcGIS pro

I did calculate Hydrology with Spatial Analysis tools==> Hydrology and now, I have streams and Watershed. In each watershed, I need to extract the longest Flow as a polyline for calculate slope. What ...
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0answers
530 views

SAGA: could not initialize data objects (QGIS 3.6, Mac 10.14)

I was trying to generate a catchment area from a DEM and got the error message: The following layers were not correctly generated.<ul><li>/var/folders/ft/rbsnpzy96r76t8rkj5fdtzc40000gn/T/...
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0answers
51 views

Flow Distance Not Calculating for Entire Raster

I am trying to calculate the height above the nearest stream for an area. The problem is, it only does so for a portion ( the colored area below) of my area of interest. In the pic below, the black ...
2
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1answer
52 views

Creating symbols between connecting lines to represent line boundaries

I am trying to figure out a way to create markers as seen from the attached image where an angled line (in dark red) is created between the lines to represent a connecting stream. With the data I am ...
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0answers
15 views

Calculating SCS curve numbers using DSM instead of DTM

Are the curve numbers (calculated by SCS Curve number method) through DSM (Digital Surface Model) valid? Most of the SCS curve number studies focus on calculating curve numbers through a DTM (Digital ...
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1answer
111 views

Finding glider reachable area / catchment area with custom slope?

I'd like to produce maps for gliders in mountains. I'm looking to display the reachable area by a glider taking off from a given point (obviously with the corresponding DEM). For a first approach I'...
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0answers
169 views

Howerive vector stream network from a DEM using D-Infinity Flow Direction algorithm?

I have been working with a 1m LiDAR derived DEM to create a vector stream network. Using the D8 flow direction, D8 flow accumulation, and a specified threshold, I was able to create a vector stream ...
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1answer
72 views

Using GageWatershed Function in TauDEM?

I have a D8 flow direction raster made from with TauDEM's D8FlowDir method and a point vector with an attribute 'id' for each. For some reason when I use these two as input in the GageWatershed ...
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1answer
144 views

How can I find the elevation a set distance upstream and downstream from a layer of crossing locations

I have a channel network which I've intersected with a proposed road network to produce crossing locations. I need to find the channel slope averaged over a 20m stream length. I also have a raster ...
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1answer
48 views

Watershed layers that drain to ocean?

I have been searching for a watershed layer for California or for the entire US that encompasses all upstream area from ocean outlets (e.g. the entire catchment draining into each ocean output). I ...
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0answers
44 views

Is there a way to produce a line on a raster, which direction is based on cell values?

I am looking at a raster layer where each cell has one of 8 values, indicating where flow from the cell is directed. Is there a way to select any given cell, and have a line drawn which will follow ...
2
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0answers
57 views

Channel network from high resolution DEM for flat areas

I'm working on channel network extraction from a LiDAR DEM (square grid max resolution 0,25 cm), and my area of study is vary flat with some part below the sea level. I applied the classical valley ...
2
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2answers
474 views

Fill sinks until a known value

I have a DEM and I want to fill every sink with a Value of 2 meter. If a sink is less than 2 meter, it is filled full and if it is bigger, it is filled until it reach 2 meter. The problem is that ...
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1answer
321 views

GRASS Error: WARNING: segment zero_fill(): Unable to write (No space left on device)

I was trying to define the drainage patterns and to delineate some catchments based on a 30m DEM using r.watershed --overwrite elev=DEM accumulation=Accum drainage=Drainage -m but grass would ...
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1answer
516 views

Shifting entire river channel in HEC-RAS?

This question is specific to the HEC-RAS software. I'm trying to use the software to shift a river channel. I've used the Geometric Data Editor for the Cross Sections to edit the positions of the ...
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1answer
113 views

How can I reduce the size of shapefile (.prj, .shx, .shp) up to 8 MB? [closed]

It is sub basin photo which I want to upload to CHRS so that I can to download satellite precipitation data (https://i.stack.imgur.com/EQt3v.jpg)
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1answer
1k views

Choosing parameters for SAGA Wetness Index?

I've been working with SAGA GIS to calculate the Topographic Wetness Index of an alpine catchment. I am using the tool Terrain analysis > Hydrology > SAGA Wetness Index because, compared to ...
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2answers
541 views

Define catchment boundaries with GIS using R

Using a DEM, I want to define catchment boundaries for a given location on a river. Basically, what area drains into this point. In ArcMap, I can do that with flowacc and other tools; but I'd like to ...
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0answers
36 views

Split single polyline network at a point feature to make unique fields with unique distances

I am working with a large river network polyline shapefile. I am trying to calculate a dendritic connectivity index using a point shapefile representing locations. The river network shapefile has a ...
0
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1answer
89 views

arcpy fails to get spatial reference in hydro script

I have an ArcPy script that extracts a stream network from any chunk of terrain. It takes the terrain and if it's in a GCS, it projects it to the correct UTM zone prior to further processing. Though ...
4
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1answer
123 views

Selecting or highlighting upstream elements

I would like to use the information from the Swedish SMHI related with their hydrological model elements (catchment areas) that have a Containment hierarchy structure, each element has the information ...
1
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1answer
655 views

tauDEM flow accumulation (D8 or D-infinity) results is NA-values for some major rivers

I am having some trouble with tauDEM that I am hoping someone can give me some advice on. I'm running tauDEM via command line through R-studio. I am working with some 30m resolution SRTM DEM data in ...
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1answer
2k views

Watersheds in SAGA Fill Sinks Wang & Liu tool

I'm delineating some coastal subbasins using open source software. I have asked a similar question before (Delineating coastal subbasins using SAGA GIS or GRASS in QGIS?). I found that using SAGA Fill ...
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1answer
207 views

How to Create SCS (now NRCS) Curve Number Grid using GIS with European map (ESDAC dataset)?

After finishing the watershed delineation, and after creating the HMS schematic in Arcmap, i was trying to include the land use map and soil map in the process, by using the CNgrid preparation by ...
0
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1answer
36 views

Choose between two points with same name but different attributes in ArcGIS

I have a dataset of thousands of points, made by the intersection of flowlines with waterbody polygons. Each polygon has two (or sometimes more, if the waterbody has multiple tributaries) points made ...
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1answer
206 views

Find minimum downstream flow distance from each polygon to any polygon in other feature class

The Problem: I have two polygons feature classes, let's call them "SourceAreas" and "DangerAreas". For each SourceArea, I need to know if water could flow to any DangerArea and if so, what is the ...
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0answers
1k views

Displaying flow direction using arrow in ArcGIS Desktop?

I created a flow direction raster out of a DEM using ArcGIS Spatial Analyst Tools/ Hydrology, so the directions are coded in raster values as displayed below. [http://desktop.arcgis.com/de/arcmap/10....
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0answers
41 views

Automatically locating endpoints (river sources) in a stream network

I have a stream network in ArcGIS 10.2.2 and I would like to know if it is possible to automatically add endpoints based on the stream network. The network is pretty big and doing this manually ...
2
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1answer
166 views

Assigning land cover type (in shapefile) to hydrologic soil shapefile in QGIS?

I have a land cover and a hydrologic soil group shapefiles which cover my watershed. They have different polygons. For example, a forest type land cover (one polygon in land cover shapefile) may ...
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1answer
146 views

TauDEM Model Availability

I'm trying to find the TauDEM Model Builder Models toolbox. I'm teaching myself how to use TauDEM to delineate watersheds. After running through some examples I started putting the modules together ...
2
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1answer
425 views

Flow accumulation algorithm open source code in C++ on Windows

I'm looking for flow accumulation open source implementation ( C++ or C# would do, Python no), on Windows, preferably the source code comes with Visual Studio project files so that I can just build ...
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0answers
141 views

Seeking open source alternative to RivEX (add-in for ArcGIS designed to process vector river networks) [closed]

I wish to process a river network - for the assessment of hydrological potential. RivEX is one addin (not free) which could be used with ArcGIS. Is there any alternative to this?
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2answers
61 views

Acquire direction between points along route

How can I generate a directionality attribute between two points along a route/line? Currently I am using Network Analyst to determine closest facilities, but I need a direction (upstream/downstream) ...
2
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1answer
100 views

Cumulative distance along a raster stream network

I am looking to calculate the cells along a stream network from starting points to a maximum distance and stopping points. I need something like r.cost in GRASS (https://grass.osgeo.org/grass75/...
3
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2answers
281 views

How can the flow accumulation in a hydrological model/stream network be maintained across tiles of a large area of interest?

My study area is too large to be processed in its entireity by any hydrological modelling software I have found yet. I will have to break it up in to smaller areas, but there will be flow across these ...

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