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
526 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
302 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
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 ...
0
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1answer
70 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
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 ...
0
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1answer
355 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 ...
0
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1answer
978 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 ...
0
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1answer
150 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
33 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 ...
0
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1answer
135 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
918 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
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 ...
2
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1answer
111 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
95 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
297 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
98 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
55 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
63 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
194 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 ...
2
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1answer
412 views

Calculating floodplain for river section using DEM only in ArcGIS Desktop?

I'm looking to create areas where water might go when a river floods its banks. I have a pretty good resolution DEM (5ft^2 for each "square"). I'm not looking for anything super accurate or precise ...
8
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3answers
595 views

Locate wet patches using DEM

I'm searching for a way to determine the location of wet patches, after rainfall, in a DEM. By this, I mean puddles. We are investigating the best locations to locate paths for recreational use. ...
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0answers
946 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
39 views

SAGA Maximum Flow Length problems with the Coordinate systems

I'm new to SAGA. I've got a srtm data set from europe and want to charge the maximum flow length especially from the river Elbe. The data is in WGS84 So first I ran the tool "Fill Sinks"(Wang & ...
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2answers
185 views

Interpreting GLDAS 2.1 precipitation data

I am trying to use the GLDAS 2.1 3-hourly precipitation datasets available at: The dataset is documented here: https://hydro1.gesdisc.eosdis.nasa.gov/data/GLDAS/README_GLDAS2.pdf The data is ...
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0answers
365 views

SAGA functions not writing output raster using QGIS 3? [closed]

I'm using QGIS 3.0, using a SRTM 1 Arc Second to perform hydrological analysis using some of SAGA functions (such as Fill Sinks), if I choose temporary output, it works fine; if I choose to save to ...
5
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2answers
267 views

Performing Weighted Flow Accumulation in GRASS?

I would like to calculate a weighted flow accumulation raster with GRASS. I have a DEM and a rainfall raster. I am looking to calculate the rainfall accumulated downstream. Basically, it is similar in ...
5
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1answer
286 views

Calculate Polygon Centerline with a LeastCostPath approach

I'm working on deriving the centerline of a polygon, similar to this question or this one, using a different approach. I'm 90% done with the task, but cannot reach the final step. My approach is to ...
1
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1answer
178 views

Hydrological conditioning using stream vector in GRASS?

I would like to make an hydrological conditioning of a DEM using an available stream network in vector form. I know r.hydrodem but it doesn't allow to use the stream vector. I need something to burn ...
0
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1answer
42 views

Find all polygons upstream of a set of points? [closed]

Given two datasets 1) polygons for global river basins and 2) points for global hydro power dams; how can I determine the upstream basins for each dam? Not sure where to start with this, looking for ...
2
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1answer
377 views

Flow Direction created from depressionless DEM inaccurate in flat areas

I am trying to build a flow direction raster for an area from a 1m DEM created from LiDAR. I need this in order to build a flow accumulation raster, so I can use that to build a stream network. I have ...
0
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0answers
638 views

Preparing SRTM (hgt) for use in SAGA GIS?

I am trying to prepare a raster file which i could use with SAGA processing tools for hydrologic analysis in QGIS. I am using Win 7, 32 bit, QGIS 2.14.20 and SAGA 2.3.2 I downloaded the srtm file in ...
4
votes
1answer
163 views

Limiting flow direction to D4 instead of using D8 in ArcMap?

Is there a way that I can limit flow direction to D4 instead of having it use D8? Preferably looking for a way to do it within ArcMap.
1
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2answers
192 views

Figuring downhill gradient slope to riparian area on ArcGIS 10.5

I am currently working on constructing a countywide riparian area, which normally consists of the integration of water bodies, wetlands, wildlife corridors, flood prone areas and hydric soils. We ...
2
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1answer
359 views

Which algorithm is used for fill sinks in arc hydro tools?

How I can get information regarding the % of voids filled using fill sinks in DEM and the algorithm used to fill the voids using arc hydro tools?
1
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1answer
259 views

Error running TopologicalBreachBurn in Whitebox GAT

I am trying to execute the TopologicalBreachBurn script in Whitebox GAT. This is my first time using this software so am generally unfamiliar with how it operates. I imported a DEM as an ASCII .txt to ...
0
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1answer
178 views

Find the nearest point on a stream network from a given point?

I have a vector layer for stream network created by r.stream.extract and then vectorized stream file using r.to.vect of grass algorithm in qgis. I want to find nearest point for a given point on ...
1
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1answer
113 views

Stream order from flow accumulation raster

I am looking to get Strahler Stream Order vector from a flow accumulation raster of a river network. I only find solutions with an elevation or direction raster. Can I do this with GRASS?
-4
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1answer
555 views

Fill DEM with water [closed]

I want view how a volume of water calculated with Hydrologic Study, accumulates in lower parts of my DEM at 1 meter resolution. My goal it's view the level that water reaches inside the raster. It's ...
6
votes
1answer
706 views

Delineating coastal subbasins using SAGA GIS or GRASS in QGIS?

I'm having some problems trying to delineate watersheds using the SAGA watershed delineation tools in QGIS. I have a SRTM DEM (cell size 30 m) which I set the water cells to NULL values, following ...
1
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2answers
2k views

Longest Flow Path in QGis

From a DEM of a watershed, how is possible to calculate the longest flow path? I know this questions has been asked before but I haven't found a complete solution yet.
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0answers
39 views

Production of DEM on ArcMap from LiDAR data? [duplicate]

I am trying to produce a DEM for my dissertation (i'm relatively new to ArcGIS) so that I can conduct hydrological analyses of catchments. I have downloaded LIDAR (.laz 2x2 km) data and have created a ...
3
votes
2answers
954 views

QGIS: Saga Channel network: how to prepare SRTM data

I am trying to use the Saga toolbox (2.2.3) in QGIS (2.18) to create a channel network from SRTM data using this tutorial 1. It works, but the result I get when using the DEM that comes with the ...
2
votes
1answer
216 views

GRASS r.basin resolution error at strahler stage

I built a composite DEM of Florida using USGS NED 1 30m DEM tiles. I used r.patch to convert the individual tiles into a single raster and then projected it into a new region with the EPSG:26958 ...
4
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2answers
1k views

Generate Height Above the Nearest Drainage (HAND) using QGIS

I have a DEM I want to generate a HAND for and want to do so in QGIS. Does anyone know of any plugins or the processing steps to be able to do this?
3
votes
1answer
242 views

Selecting contour lines with higher elevations on either side

I want to select contour lines that have lower elevation values from neighboring contour lines. I'm using ArcGIS but do not have the hydrology tool set. I can use open source if needed. I thought ...
1
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2answers
49 views

Where water will be on a mudflat as tide comes in/goes out?

My study area is large intertidal mudflat in NE England. I want know where the water will be depending on tide height. The attached shows an aerial of my study area. I've photoshopped in the blue ...
6
votes
1answer
483 views

Lowering density of GRASS r.stream.extract result?

I am fiddling with the GRASS plugin in QGIS to produce watersheds and drainage basins as well as being able to identify all the basins and watersheds leading to one point (depending where i chose to ...
4
votes
1answer
372 views

Obtaining length of river upstream of points up to next point using ArcGIS Desktop?

I am carrying out a study which aim is to come up with a list of priority obstacles to fish migration to be removed based on those where more extra habitat would be created after the modification. I ...
1
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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 ...
1
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1answer
128 views

Delimit Hydrographic Basin, based on a single river

I find myself doing a hydrological study, where I have to delimit the river basin based on a single river (polyline). I have the DEM where the river of my interest is, and I have the river as a ...