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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22 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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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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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 » ...
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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
121 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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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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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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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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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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57 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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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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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 ...
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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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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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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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316 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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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
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 ...
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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() == ...
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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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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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1answer
73 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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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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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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1answer
28 views

Renaming field of shapefile in SAGA

I want to rename a field of a shapefile in SAGA. I tried: saga_cmd table_tools 23 -TABLE %dgm_snap_berg% -FIELD ID_1 -NAME Berg_ID %dgm_snap_berg% - path to the shapefile ID_1 - field supposed to be ...
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1answer
50 views

Getting closest point-feature of another point-feature

I have two point-shapefiles. For each point-feature in one of those two files I want to identify the closest point-feature from the other file and save the "ID" of this point as attribute. ...
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1answer
37 views

Extract areas up to 90% of mountain height

I have a DGM of an area in which I need to Extract the valleys Extract the ridges Identify the areas which go from a valley up to 90% of the ridge height (e.g. a valley has an elevation of 0m, the ...
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36 views

Short streams and tiny basins | QGIS-SAGA

After watching a lot of tutorials and trying all approaches I still somehow manage to get streams that are too short over my DEM, resulting in very small basins. I do it the standard way: Get a DEM ...
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24 views

Can the SAGA algorithm “Local Minima and Maxima” not find any minima and maxima if the spatial resolution is too high?

I work with a 5cm high resolution CHM to determine tree tops. However, the algorithm does not work. If I resample my data set to 25cm, I also get a result.
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62 views

SAGA GIS getting 90 degree slope in the whole terrain

I´m studying a jungle area in Peru, and when I try to calculate the slope with the "Slope, Aspect, Curvature" tool from SAGA v7.7.0, I get that the whole terrain has a 90-degree slope. In ...
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185 views

Convert cityGML to SHP?

I want to convert cityGML files into shapefiles which show the 3D-objects from above in 2D. It would be also nice to keep the height of the objects in the attribute table or as z-value. I want to use ...
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41 views

Update from QGIS 3.10 to 3.14 on Ubuntu with ubuntugis-unstable

I just formatted my laptop and wanted to make a fresh install of all the spatial stuff. I thought I'd use the ubuntugis-unstable ppa. But apparently this still comes with QGIS 3.10. So I wondered what ...
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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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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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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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2answers
59 views

Measure Points to Coastal lines?

I would like to measure the shortest distance from multiple points to a any part in a coast line of three different costs. How do I do this with QGIS or with SAGA GIS?
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160 views

How is Topographic Position Index calculated?

My understanding of how topographic position index is calculated is: TPI = cell value - (mean of cell values within defined neighborhood) But, I see that Weiss' original poster (http://www.jennessent....
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94 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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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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1answer
68 views

How to configure Saga Tools on Qgis script

I'm trying to use the process saga:paramemeltonruggednessnumber as following : melton_saga = processing.run("saga:parememeltonruggednessnumber", {'DEM' : path_filled, '...
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1answer
147 views

QGIS (3.10.7) SAGA tools resulting in “The following layers were not correctly generated.”

I am using QGIS 3.10.7 and want to use SAGA tools. I am using an ASCII file (.asc) with a projected coordinate system - EPSG:26919 - NAD83 / UTM zone 19N - Projected. When attempting to use the tools, ...
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1answer
705 views

Ubuntu 20.04 with QGIS 3.14 (pi) SAGA is missing

After updating to QGIS 3.14 in Ubuntu 20.04, SAGA is not available. The Log Panel (View->Panels->Log Messages) said SAGA didn't load. In the Processing Toolbox, the SAGA category is missing.
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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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69 views

Calculate stream locations and Strahler order from DEM in QGIS

I am trying to locate streams and determine their order in QGIS. I have tried using several of the procedures described in answers to similar questions, but none of them seem to work. I have filled ...
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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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24 views

SAGA Aggregate tool in QGIS yields empty result

Using QGIS 3.10.1-A Coruña, the SAGA Raster Tool Aggregate appears to yield no output, despite finishing normally. No new layer apears in the Layers window, nor do I see an output file specified in ...
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22 views

Identify false outlets on a river network

I have a river network that is very poorly defined (lots of gaps). I need to identify all the false outlets. The picture below provides an example of one of these false outlets. The image shows ...
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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
128 views

How do I get average temperatures and precipitation data into QGIS or SAGA GIS?

I need average temperatures and precipitation data (if possible as grid) for Germany and I found this source: https://opendata.dwd.de/climate_environment/CDC/ But I have no idea on how to load it ...

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