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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1answer
55 views

Getting an error when using Natural neighbour (QGIS 3.16 Hannover)

I am having trouble with the following: For a project I need a topographic map with contour lines of a specific area. I've googled around and the only suitable option (without buying expensive ...
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0answers
20 views

QGIS 3.18 and 3.16 LTR install. GRASS and SAGA not working. MacOS OSX

I have tried to update QGIS on Mac to either version 3.18 or 3.16 using the installers on the QGIS page. I have been having issues getting the GRASS and SAGA providers running. Error message below. ...
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1answer
286 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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1answer
30 views

Error while running SAGA algorithms in QGIS 3.10.14-A Coruña

I've been trying to run several hydrological algorithms (Strahler, Fill Sinks etc) from SAGA in QGIS ltr and I keep running into the same error: The following layers were not correctly generated.C:\...
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1answer
125 views

Installing SAGA in QGIS 3.12 on Ubuntu 18.04.04

I have installed QGIS 3.12 through the Ubuntu Store and installed SAGA 7.3.0 through: sudo apt-get install saga I tried to install QGIS through apt-get, as instructed in the documentation of QGIS ...
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8answers
42k views

How to set all pixels with value <= 0 to “nodata” in DEM raster?

I have a DEM raster with pixel values between about 3000 and -0.0003. I need to set all pixel with a value of 0 and smaler (<=0) to "nodata" (for later raster calculations and to reduce the ...
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1answer
26 views

Merging two landsat images

I have several Landsat 5 Images to merge together. As far as I saw from tutorials and previous questions there are two main methods (and none seem to be working for me): 1 - raster » miscelaneous » ...
2
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1answer
380 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 ...
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0answers
20 views

Using SAGA to create covariates

I am creating a soil property map. I am using SAGA to create my covariates. For now, I am using SAGA wetness index for my 50 acre research area. Couple of questions: I was able to use the basic ...
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1answer
211 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 ...
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1answer
92 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
120 views

Rasterise a vector layer but relevant column is not numeric in QGIS

The software I'm using is QGis 3.16.0. In order for a study project, I need to rasterise a vector layer (polygons) in order to classify certain classes of a certain attribute column with the process &...
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0answers
24 views

Calculating Saga Wetness Index from LiDAR-derived .ASC files in RSAGA

I am trying to run SAGA Wetness Index on a large number of .asc files that were derived from 1-m LiDAR. Due to the large size/amount of data (each .asc file is ~1000 MB and I have ~685 files), I would ...
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1answer
74 views

Geostatistics in SAGA: Strange variogram output

I'm verry new to geostatistic. I'm using variogram to visualize a data (available in .shp here). Then I got the data like this or from this link (updated zip files contains shp, shx, prj, mshp, dbf, ...
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0answers
29 views

Error message while running Strahler order for river delineation

I wanted to make river network using Strahler order in SAGA with filled DEM as the input, but there is an error message keep appearing: QGIS version: 3.14.0-Pi QGIS code revision: 9f7028fd23 Qt ...
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3answers
89 views

Decreasing resolution of binary raster layer, but retain specific data using QGIS

In QGIS 3.16.2, I have a binary raster layer in which I would like to decrease map resolution without losing any value = 1 pixels (white in the example). I have tried exporting and changing the pixel ...
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5answers
22k views

Enabling SAGA in QGIS?

A similiar question has been asked recently as How to make GRASS and SAGA tools capable to use in QGIS? However I have some specific queries and process I have tried which are probably better in a ...
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2answers
1k views

Errno 13 “Permission Denied” when running tools and plugins on QGIS

I am having an issue with multiple tools when using QGIS where I am constantly getting PermissionError: [Errno 13] Permission denied type errors. A lot of it seems to be associated with tools that use ...
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2answers
867 views

Missing Dependency in SAGA. Orfeo Toolbox does not work

I am trying to perform segmentation from Orfeo Toolbox (QGIS last version 2.2), whenever I try to use the toolbox, I get the following message: Oooops! The following output layers could not be open ...
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1answer
265 views

Qgis SAGA Upslope Area for several points automation

In the Upslope Area tool from SAGA it used to be possible to import the point file with multiple points and it would create several catchment/basins areas for those points. Now, it is only possible to ...
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1answer
97 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 ...
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2answers
106 views

Find nearest point with the same attribute

I have a points data set of toponyms with several thousand elements. There are a lot of duplicate names that fall in two categories: legit ones, i.e. different places with the same name at several km ...
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1answer
31 views

SAGA Point Statistics for Polygons

I am running QGIS 3.10 on a MAC using Catalina (and I also tried on QGIS 3.4) and tried to run SAGA Point Statistics for Polygons. Every time I run it I get an error with it trying to create the layer....
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1answer
127 views

Integrating SAGA 7.8.1 into QGIS 3.16 (OS Windows 10)

I want to calculate the PV potential of roofing using QGIS, similar to this post: How to calculate total PV potential of a roof using QGIS?. However, my SAGA version in QGIS does not show me the ...
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2answers
507 views

Do SAGA tools work on QGIS 3.10.7?

Is anyone successfully using SAGA tools in QGIS 3.10.7? I have downloaded QGIS 3.10.7 on multiple PCs and a Mac. All of them have resulted in the same problem when I try to run SAGA tools. A message ...
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0answers
17 views

SAGA error message

I want to run the QGIS integrated SAGA tool Sky View Factor. This is the error Code I receive and need help to solve: QGIS code revision: b381a90dca Qt version: 5.11.2 GDAL version: 3.1.4 GEOS version:...
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0answers
32 views

Cannot run SAGA commands due to PATH problems

I have tried to upgrade SAGA on MacOS 10.15.7 to use a version more recent than 7.3 in QGIS 3.16 since it has been unable to correctly export files using the Ordinary Kriging and Semivariogram Surface ...
14
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2answers
5k views

How to smooth large vector polygons from Raster

I have a landuse classification raster file (6 classes) of a large area. But I need it in vector polygons so I vectorised it. No problem so far, but the result is - of course - that every pixel is ...
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0answers
17 views

Accuracy assessment (confusion matrix) of image classification from Landsat imagery in SAGA GIS

I have classified Landsat images in two different classes, namely pervious and impervious, in SAGA GIS, using training sample in polygon shapes. This training sample has only one column of attribute ...
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1answer
67 views

Unexpected error while RSAGA raster calculations

I want to use RSAGA package in R to calculate the topographical wetness index. However, while applying the rsaga.wetness.index() function, R gives me an error message (see below). My question is, ...
2
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1answer
338 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 ...
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1answer
90 views

QGIS export DEM to SAGA grid - no coordinate system

I have created a DEM using survey points from a GNSS system. Works like a charm so far. I can extract elevation lines etc. However, when I export it as a SAGA grid it looses the coordinate system. I ...
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0answers
32 views

Calculate PV rooftop potentials in Berlin QGIS 3.16. (OS Windows 10)

I want to analyse PV potentials of roofing in QGIS (v. 3.16). I am experienced in vector data analysis but have barely worked with raster data sets. I therefore have no experience and am asking for ...
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2answers
157 views

Issue with CRS in R's writeRaster and SAGA's raster-format

I have a normal RasterLayer in R and I would like to write it to a file and visualize it in QGIS. When I look at in in R it says: class : RasterLayer dimensions : 3035, 1469, 4458415 (nrow, ...
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1answer
249 views

Python fmask from command line or in Python script

I'd like to mask some clouds in Sentinel-2-Images with the python-fmask-library. As I'm not too experienced with Python and remote sensing, I have some questions. When I installed the library I ...
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0answers
114 views

How to avoid error in “SAGA Strahler order”-process when running it on a merged terrain model file

I am trying to create a catchment in QGIS 3.8 following this tutorial: https://www.youtube.com/watch?v=2fvy9xtAHc4 However, my terrain model is originally divided into 4 overlapping tif-files. I can ...
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2answers
315 views

SAGA problem issue in QGIS

While running SAGA 7.30 version in QGIS 3.16, they show an error about that version is not supporting and checking about a new version for up-gradation that might solve the issue but 7.30 version is ...
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0answers
46 views

Line along points with no continous ID and creation date/time

I have a huge points file. The points are along a route network. I would like to build lines by going from point to point - but there is no chronology given! The "ID"s seams to be chaotic ...
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2answers
2k views

Seeking open source alternative to ArcGIS Desktop's Integrate tool?

I need to snap about 1000 lines in one layer to the lines in another layer (there are about 5000 lines in the second layer). The lines to be snapped are about 15 map units away from the base layer ...
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2answers
54 views

Counting pixel values of NDVI

I'm trying to calculate the amount of pixels with the value of 0.3 to 0.7 between two different rasters (each raster of a different year) to calculate the loss of green spaces trough time. Is it ...
0
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1answer
90 views

Algorithm “Merge Layers” from SAGA not showing in QGIS Modeler

I'm trying to merge multiple vector-layers via the modeler in QGIS 3.14.1 as a part of a bigger model. As a matter of fact the QGIS-native "merge layers" algorithm doesn't work here, for the ...
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0answers
29 views

Syntax for SAGA resampling

How can I link the GUI to my processing code as shown in the image below so that it uses any number selected (between 20 and 100) in the spinSize value space? # Perform task if layer.type() == ...
2
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1answer
72 views

Convex hull that follows irregular points distribution

Based on an irregular distribution of points (longitude,latitude), I obtained the convex hull below (I use saga_cmd with polygon convexity in 1). Would you have a way to create a convex hull that ...
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1answer
37 views

SAGA RESAMPLING SYNTAX

How can I solve the problem shown below: I am trying to build a plugin that allows me to resample the raster data to any desired resolution of my choice with 20 being the minimum input value, as ...
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0answers
44 views

SAGA GIS memory allocation failed

I am trying to run mosaicking using the script below: saga_cmd grid_tools "Mosaicking" -TARGET_DEFINITION 0 -GRIDS "/media/geodev/Data2/test_data2/2019-06/2019-06-19/Flight_Plan_B_2/...
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1answer
53 views

How to convert grid to vector in SAGA?

I need to convert raster to vector, I have data from a field in two layers. In the first i have DSM (digital surface model) and DTM (digital terain model) in the second layer. Based on difference in ...
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2answers
978 views

QGIS- extract raster information into a point return nulls

I have a 1) raster layer and a 2) point layer. I want to extract the pixel value to each point, but it is not working when using this tools (QGIS): plug-in "Point sampling tool" (the new shapefile ...
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2answers
1k views

point thinning/point selection based on distance threshold in QGIS/GRASS

I need to thin a point vector later based on the distances amongst points. So I have a threshold and wish to omit all records but one that is below a distance D representing a distance between points. ...
40
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5answers
68k views

Splitting shapefile into separate files for each feature using QGIS or SAGA [closed]

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 Desktop - see ...
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0answers
25 views

Update mshp-file with SAGA GIS?

I want to update the mshp-file of a shapefile with SAGA. My issue is: I renamed some columns of a shapefile with SAGA (saga_cmd table_tools 23). For renaming I had to give SAGA the dbf-file, because ...

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