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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4
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1answer
115 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 ...
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226 views

SAGA hydrological analysis in QGIS 2.8 on Mac

I am running QGIS 2.8 on a Mac machine and I want to calculate the catchment area using SAGA - Catchment Area. It starts running but after a while when QGIS wants to open the generated files there is ...
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169 views

Extract representative slope profiles from hillslope polygons

With the help of the Whitebox Geospatial Analysis Tools I was able to easily extract hill slopes from a river network in combination with a flow direction map. Now I would like to extract ...
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0answers
615 views

Creating water surface from vector line in QGIS

I want to create a raster surface representing the flood level in a creek based on output from a 1D hydraulic model. I receive a 3D profile of the water surface in a creek line as a 3D Polyline (...
3
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0answers
156 views

Which geostatistical tools to use to determine surface changes over 40 years?

I have a data from the Weather station with SWEmax (snow water equivalent) collected over 40 years. I need to interpolate the data over my river's watershed and then, somehow, determine the ...
2
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0answers
9 views

TauDEM: How to extract the longest flow path from an outlet to the basin divide as a shapefile

Using TauDEM I've created a number of derived raster products from an initial 30m SRTM DEM with a statewide (South Carolina) extent. Using the D8 modelling methods, I've created both the D8 Flow ...
2
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0answers
41 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
130 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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0answers
41 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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0answers
106 views

Choosing diffusion coefficient and other parameters for r.sim.water in GRASS7?

I'm trying to run r.sim.water in GRASS7 to simulate overland flow during a heavy rain event. My DEM has a resolution of 1m. I prepared it by adding values for buildings and included ditches and ...
2
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1answer
58 views

Optimizing pixel extraction from GeoTiff using Python

I am creating IDF Curves for work using python and 30-minute rainfall rate rasters. There are 24 rasters per day and about two decades worth of data. I basically input lat/lon coordinates and my ...
2
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1answer
150 views

Connectivity of Streams

I have a line vector layer containing streams (see image below). What is the easiest approach to determine the connectivity of each stream segment (eg. sum of upstream nodes)?
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1answer
12 views

TauDEM fails to create stream network shapefile (-net option) when running StreamNet method on Ubuntu

When I try running TauDEM's "StreamNet" method including the optional -net flag to create the stream links / channel network as a shapefile, it fails with a lot of errors like: ERROR 10: ...
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30 views

How to interpret the Maximum flow path length raster, from the SAGA Maximum flow path length tool

Does anyone know how to interpret the Maximum flow path length raster, after running the SAGA Maximum flow path length tool? I have used this tool and received a raster but I'm not sure how I can get ...
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0answers
46 views

Get catchment area of a lake polygon in R

I have several DEMs as geotiff files which I load into R using raster::raster. Additionally, I have lake outlines (located within the DEMs) in the form of shapefiles which I load into R using raster::...
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0answers
40 views

Why am I getting a straight flow path (stream) in obviously varying terrain -QGIS

Does anyone have suggestions on why the streams are sometimes represented as longer straight lines, even though the hillshade and contours generated from the same DTM (filled) clearly indicate that ...
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0answers
66 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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0answers
32 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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88 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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98 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
274 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
14 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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0answers
32 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 ...
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0answers
934 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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40 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 ...
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0answers
960 views

Qswat in newer version of QGIS

How can I setup QSWAT in newer versions of QGIS ? The link here says QSWAT requires QGIS 2.6. I tried installing QSWAT in new versions and it couldnot be done. Is there a way to install QSWAT in new ...
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0answers
107 views

Adding curb/gutter and subsurface storm drain networks to watershed analysis in QGIS

I need to do a neighborhood scale drainage analysis. The analysis needs to accurately show the drainage area to each storm drain inlet. Using GRASS on QGIS 2.12.1 on OS X, I have been able to ...
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0answers
156 views

calculate flow accumulation in a river with two outlet points

I'm trying to calculate flow accumulation layer (with arcGIS) in a basin with 2 outlet points. I have used "dem reconditioning" tool to modify my dem according to a vector layer, which contains my ...
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0answers
68 views

Deriving Stream-Velocity out of a DEM

I'm using Arc GIS Toolbox Hydrology...everything works fine. Moreover, it is possible to derive the potential stream velocity just out of the DEM? Informations about rainfall, infiltration, hydraulic ...
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0answers
141 views

Getting distance from nearest stream and elevation to nearest stream?

I need to know if there are simple commands for this 2 points: the distance from the nearest stream, D [m], defined as the length of the path that hydrologically connects the location under exam to ...
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0answers
460 views

Why does the flow direction tool in ArcGIS desktop give wrong output (unique values from 1-255)?

I ran the flow direction in ArcGIS, and received unique values ranging from 1-255. I know that these values are wrong, and should be along the lines of 1, 2, 4, 8, 16, etc multiples. The DEM is ...
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0answers
325 views

Measuring river width every mile in Google Earth?

Given an area, can Google Earth tabulate the width of a particular river? This problem I think requires using an API to programmatically: define an area of interest identify a terrain feature like ...
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0answers
46 views

How to join hydrological data from a big area with a small area with better pixel resolution?

I use TAUDEM to make hydrologic analysis. I have a hidro 1K dem file from South America (big area) pixel resolution=1000x1000 meters. I have a specific dem file located in Brazil (small area) pixel ...
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0answers
795 views

How can we extract the stream order branch?

Actually I am new to GIS, so I don't know much about technical terminology. I have extracted a river network but now have a problem in distinguishing the branch order of stream (from order 1 to 2, 2 ...
1
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1answer
2k views

Automatically generating pour points along stream network?

The following screenshot shows the results of a water flow analysis where I identified stream order via the Strahler method in ArcGIS. Now I need to generate watersheds for 2nd order streams and ...
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0answers
608 views

Problem in running r.sim.water

I am trying to run the r.sim.water in GRASS. I have calculated the partial derivatives dx and dy rater map using r.slope.aspect. I am using this elevation map [1] to get the time-series depth map. But ...
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0answers
169 views

Open-source tools for run-off depth calculation

I am working on modeling surface run-off (in ArcGIS 10.2) due to a rain event (e.g., 5 year rain for a duration of 30 mins.) over an approx. area of 30 km2 for which I have a DEM and necessary soil as ...
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0answers
143 views

Hydropower Calculation

I have assigned the elevation and the volume flow to each point at a river (with v.to.db and v.what.rast). Now I want to calculate the Elevation difference between each pair of points and then ...
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0answers
205 views

create a weight raster for a hydrology analysis

I determine affecting parameters of flood flow ( evaporation,vegetation,soil type, rainfall etc.). Then, I start to analysis using Arc Hydro. How do I relate among of affecting parameters? How can ...
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0answers
12 views

How do I determine the correct ratio to peak value for the Recession baseflow in HEC-HMS?

I am wondering if there is a way to estimate the ratio to peak value without calibration? What would be the most suitable value if I don't have a measured hydrograph to compare? Thanks for any ...
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0answers
12 views

How to aggregate properly 8-days MODIS ET to a monthly ET?

I am looking for a robust method to aggregate the 8-day MOD16A2 (or MOD16A2GF) ET_500m values to monthly ET. Since ET_500m and PET_500m, are the summation of 8-day total water loss (0.1 kg/m2/8day). I ...
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0answers
27 views

Catchment area raster values

In order to calculate TWI, I had to generate a catchment area raster, but I don't understand what the values of pixel represent. Any clarification? The DEM is projeted in EPSG : 2154, so the unit is ...
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0answers
16 views

Water direction and intensity of superficial flow

I'm working on maps that the goal is: to display the direction and intensity of surface water flow. I have the DEM for the watershed and generated the direction of flow, but I don't know how to ...
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0answers
56 views

Watershed delineation using hydrological Python library

We would like to delineate watershed polygon for a given pour point using hydrological Python library. Until now, we have tried these libraries: pyshed Grass (r.watershed) Whitetoolbox We have ...
0
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1answer
43 views

Cascading order of basins (next downstream basin) in QGIS, R, or Whiteboxtools

I am conducting a hydrologic analysis of DEMs. Suppose that I have the following basins in an area as shown below:. I need to get the cascading order of each of the basins. In other words, I need to ...
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0answers
22 views

Monthly albedo data for VIC

I am trying to download Albedo data for my research area. On NASA's Earthdata website I used the MODIS product MCD43A3,. First reason why I haven't downloaded the data is because my research period is ...
0
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0answers
151 views

Get catchment delineation with multiple outlets in QGIS 3.4 or 3.8

I'm starting with a DEM, then I generate a drainage direction layer (ldd). Then I'm trying to get all the watershed basins for multiple outlet points in a QGIS plugin I'm developing. I can get them ...
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0answers
36 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
84 views

QGIS Grass 7 r.fill.dir

The following layers were not correctly generated.C:/Users/JIM/AppData/Local/Temp/processing_e2688a45d8934d16a2269a7ef6af8cbd/7eefcc8d13144f598fa7ab5bb5d657b8/output.tifYou can check the 'Log Messages ...
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0answers
31 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 ...