Questions tagged [saga]

SAGA (System for Automated Geoscientific Analyses) is a GIS toolbox with many modules that can be used from the GUI, command line or accessed through R,python or directly using C++.

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24 views

Calculate median for a vector field in SAGA GIS or ArcGIS [on hold]

I would like to find the median of an attribute field of a shapefile. I can use ArcMap or SAGA GIS. In ArcMap the Sum Statistics only provides the mean value, same for the Table Description in SAGA. ...
2
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1answer
198 views

How to close open files after processing.runlag() command (Qgis: Error No 24)

I'm creating a pyqgis script. In this script I use the processing.runalg command several times. The problem is that these processes are within a for loop. After several iterations, the error number 24 ...
2
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1answer
20 views

What unit is the topographic openness (SAGA GIS)?

The SAGA GIS tool "Topographic Openness" calculates the positive and negative topographic openness and is based on Yokoyama et al. (2002) who do not specifically say the unit of the final result. They ...
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1answer
41 views

Clipping converts multiband to single band

I have a multiband raster image. I am trying to extract the AOI by using "Clip raster with polygon" option in SAGA module. The process clips the raster to the exact size of the polygon but the ...
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0answers
32 views

Error using rsaga.fill.sinks

I'm using RStudio to delineate a watershed, and have had some difficulties when using rsaga.fill.sinks. My code up to this point is as follows: #set rsaga working directory and version number myenv &...
9
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1answer
15k views

Calculating Topographic Wetness Index (choosing from different algorithms)

Topographic Wetness Index can be expressed as Ln(a/tanB) based on the idea of Beven and Kirkby (1979) where a is the specific catchment area (a=A/L, catchment area (A)divided by contour length(...
4
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1answer
1k views

Importing raster to QGIS gives CRS undefined error

I make a raster file from LiDAR .las files in SAGA. The CRS of .las is Slovenian National Grid. Then, I export it as GeoTiff (Import/Export - GDAL/OGR - Export GeoTiff). When I import it into QGIS (...
2
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0answers
35 views

Saga GIS Snap Points to Lines tool doesn't produce required results

I have two sets of data that I'm using. Points extracted from a .csv file and a road network from an ESRI .shp file (both of which I've included here: https://send.firefox.com/download/...
3
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1answer
35 views

What is the purpose of these SAGA raster mosaic parameters?

BACKGROUND: Using QGIS 3.8.0 Processing > Toolbox > SAGA > Raster tools > Mosaic raster layers, I do not understand the purpose of the Match and Fit parameters. Here's a screenshot of the Match ...
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1answer
21 views

What are the formulas used in SAGA Ordinary Kriging?

can some one name the formulas avaible in the Ordinary Kriging Modul of SAGA: What ist the exponential, spherical, Gaussian-Model, etc.?
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0answers
24 views

QGIS SAGA Overland flow distance to channel network not working

I am trying to run the QGIS SAGA tool "Overland flow distance to channel network" with a DEM and the channel network raster developed from this same DEM using the SAGA tool "Channel network." However, ...
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1answer
543 views

Determining flow path length in QGIS?

I need help with qgis flow path length. I try to run the program and when I run the program I get a raster with 0 values, as input I'm using filled raster, I don't now if I'm doing something wrong or ...
32
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5answers
54k views

Splitting shapefile into separate files for each feature using QGIS/GDAL/SAGA?

I have a polyline shapefile with about 20 kinds of roads. I would like to know how can I create automatically a vector file for each one. I am aware of how to do it using ArcGIS for Desktop - see ...
2
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0answers
470 views

SAGA not working within sextante when QGIS processing installed in Ubuntu? [closed]

Recently i decided to start working in Ubuntu (version 14.04). My first step was to add the ubuntugis-unestable repository, and then proceed to install SAGA, GRASS, OTB, QGIS and the bindings between ...
7
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1answer
1k views

Is there any way to include “universal” style/symbology in GeoPackage?

I am just playing with the GeoPackage format in QGIS. In QGIS it works nice with the style saved from QGIS but if I load it for example in SAGA the style is not applied. Is there any way to include ...
3
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1answer
57 views

Using SAGA GIS 7.X modules in QGIS

Is it possible (and how) to use the SAGA GIS 7.x modules in QGIS (as well as for GRASS GIS)?
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1answer
51 views

Error creating DEM with Nearest Neighbour tool in QGIS?

I have an issue when I am creating a DEM with the tool natural neighbour on QGIS. When I extract my data directly on Qgis I have no issue creating a DEM. My points are coming from different sources ...
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3answers
109 views

Converting raster pixels to vector cells?

Is there any way to convert raster pixels to vector cells? I mean each pixel to a polygon. I tried the SAGA tool 'Raster values to points' by choosing cells option instead of nodes option. As a ...
1
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0answers
59 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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1answer
18 views

Using Formal Class RasterLayer as RSAGA input and otput

Is there a way to use the data from the R global environment object as input for an rsaga.geoprocessor alghoritm? And if yes, can be the output also saved as a same object? I am writing chain ...
3
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1answer
156 views

Sentinel-1 SAR image is displayed upside down

I am looking at Sentinel-1 SAR image downloaded from ESA Copernicus - dhus location around south of Tokyo, Japan. File format is GeoTIFF. It looks good in QGIS. However, if I use SAGA, or SNAP, or ...
2
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1answer
115 views

SAGA landform classification crashing on MAC, Windows, standalone or with QGIS

I am trying to apply the "TPI-based landform classification" algorithm from SAGA. Originally in QGIS 2.14, on a MAC, then on windows and with SAGA standalone, but it quickly saturates memory/CPU and ...
1
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1answer
59 views

Adding two rasters in modeller

I'm trying to build a process model which uses a series of raster operations - Rasterize, Proximity, Raster Calculator. However, I couldn't seem to add two consecutive raster calculator processes. ...
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1answer
137 views

Large Scale Watershed Delineation

Using QGIS,I attempted Africa's watershed delineation taking the following steps: Downloaded DEM from earthexplorer USGS (GTOPO30) Created a mosaic of the downloaded DEM Reprojected the mosaic ...
2
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0answers
38 views

VRM tool QGIS error generating layer

I am trying to use the VRM tool in QGIS of the SAGA package. Every time I get an error message: layers could not be generated. I tried different input rasters (DEM and DTM) and kept other settings ...
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1answer
168 views

Unable to perform SAGA point snapping to line on Win and Mac

I have been trying to snap points from a shapefile to a line feature from another shapefile. However, each time I do this, I get the following error(s) (depending upon the OS used): (For OSX El ...
2
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1answer
218 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 ...
2
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0answers
51 views

Inaccurate raster values from “SAGA Extract Raster Values to Points”

I am perplexed by the results generated by the SAGA 2.3.1 Extract Values to Points tool in QGIS 2.18. I am working with Vegetation Index raster layers, which means the values are between -1 and 1. ...
4
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1answer
374 views

Writing SAGA_CMD command line formatting

I am trying to use SAGA_cmd to write a script that does the following: The united 1) Reads a series TIFF files I have in the work folder; 2) Runs a segmentation on the TIFF files on each respective ...
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0answers
27 views

No SAGA folder in processing options dialog box

I am using QGIS 2.18. I am facing this error while using EasyAHP: "The error occured during calculation. Please make sure that Processing Toolbox's SAGA provider is installed." But, I guess the ...
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0answers
57 views

Easy AHP returns error because it can not find the SAGA 2.3.2 folder

When I try to complete the AHP in QGIS 2.18.27 using easy_AHP, the plugin responds: although the SAGA tools are working perfectly by the Processing Toolbox. The SAGA configuration options in QGIS ...
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1answer
81 views

Exporting landcover clasiffication from ENVI to SAGA

I have basic knowledge in remote sensing and GIS. I have generated landcover map in ENVI 4.7. How can I transfer or Export/Import this into SAGA so that I perform other functions in SAGA. I want to ...
3
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1answer
69 views

Is there an equivalent to “keep inner boundaries” in QGIS 3?

At QGIS 3.4.7, I have some polygons that are overlapped and I use Polygon dissolver (by attribute) from SAGA to dissolve then and I check the option "keep inner boundaries", but this tool takes too ...
1
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1answer
86 views

Raster Volume Returning Wrong Volume

I have a clipped surface using Washington State Plane North (feet) added to a QGIS project using the same CRS. I am trying to calculate the area under this surface (a dirt pile) using SAGA Raster ...
3
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1answer
49 views

Cheapest path through polygons and lines from point to point

I want to find the cheapest path or the least cost path from one point to another point. The points are part of a vector map and do not lie on a network. All features being part of the map have ...
1
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1answer
83 views

Analytical hierarchy process tool - SAGA. How to configure Pairwise comparisons table?

What is the configuration and extension (.txt, .csv ...) of the Pairwise comparisons table file requested by the SAGA AHP tool- Analytical Hierarchy Process - in QGIS? Are there examples of ...
3
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0answers
66 views

Extracting GeoTIFF colours and adding to equal geometry shapefile

I have the following map in .png-format that I would like to replicate, but I cannot obtain the original data. The map shows the current water supply vulnerability for local municipalities in South ...
2
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2answers
4k views

How to interpolate a point vector layer inside a boundary (polygon layer) QGIS/GRASS/SAGA?

I have to create a heatmap of water temperatures inside a lake for which I have sample points. The map should look much like the climate maps generated by climate change models. I have the temperature ...
0
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1answer
90 views

QGIS 3.4 Stream delineation problem, lines running too far into ocean

I am using QGIS 3.4.4 Madeira version trying to delineate the stream and catchment areas of a small Bay in Honduras based on the technique of Hanz van der kwast tutorial "Stream and Catchment ...
3
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2answers
144 views

QGIS SAGA functions failing “… following layers not correctly generated. …” [closed]

I've been having an issue with the SAGA functions for a while now, I believe since upgrading to one of the early 3.x versions. No matter which function I use they all fail with the same error (...
1
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1answer
72 views

Getting QGIS Model Processing Raster Calculator Error?

I am using "raster calculator" tool of the saga in my model. The tool correctly executes raster operation like "a * 2" in value formula option but the same expression is not executed pre-calculated ...
2
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1answer
134 views

Re-projecting WGS84 to OSGB in SAGAGIS

I took some points with a GPS, and I'm trying to convert from GCS to OSGB 1936 British National Grid in SAGAGIS. I'm working with a shapefile. To reproject the vector layer to the OSGB projection I ...
1
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1answer
76 views

Relief Segmentation Tools, SAGA

Where can I find documentation on the tool Relief Segmentation of the library Terrain Analysis?
3
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3answers
829 views

Finding coordinates of given raster value? [closed]

I would like to get the coordinates of a raster cell with a given value. I suppose many cells can take the same value, in which case several coordinates should be returned. In my first problem I'm ...
1
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0answers
49 views

Error using SAGA raster creation tools. Input layer error: points?

I have a shapefile containing x,y,z values as a point vector layer. I want to interpolate these points to create a DEM. For that I use SAGA natural neighbour algorithm. However, I am not successful ...
0
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1answer
350 views

QGIS 3.4.4 and 3.6 SAGA Tools all not working with same error

C:\OSGeo4W\bin>exit Execution completed in 12.17 seconds Results: {'SHADE': 'C:/QGIS/output/HS.sdat'} Loading resulting layers The following layers were not correctly generated.C:/QGIS/output/HS....
1
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1answer
122 views

SAGA hydrology toolbox Error: select a library

Hi I am having trouble getting the SAGA hydrology toolbox running. Here when I try to fill sinks in the DEM a series of errors are flagged in the log file. This includes for 'select a library', 'DEM' ...
3
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1answer
3k views

Variogram model - SAGA on QGIS Processing

QGIS 2.14 (Win) comes with SAGA 2.12, which Ordinary Kriging supports 6 variogram model options. However, if I run SAGA Ordinary Kriging from QGIS Processing Toolbox, there is no drop down menu. Only ...
1
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1answer
149 views

LS Factor in SAGA (slope units)

In which units do I have to calculate Slope to use as an input for the LS Factor tool in SAGA (degrees, %, radians)? I couldn't find anything in the documentation.
1
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0answers
93 views

SAGA 2.3.1 makes QGIS 2.18 crash on Ubuntu 18.04 [closed]

On Ubuntu 18.04, using packages provided by universe repos QGIS 2.18.17+dfsg-1 SAGA 2.3.1+dfsg-3build7 When starting any SAGA algorithm, QGIS crashes with a "Segmentation fault" error message. We ...