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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votes
1answer
521 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 ...
5
votes
0answers
269 views

Segmentation fault in SAGA GIS

When I try to launch SAGA GIS I get this error: "segmentation fault (core dumped)" How can I solve this problem? I am using Lubuntu 14.04 64-bit.
5
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0answers
1k views

QGIS cannot open output layers

I have problem with QGIS 2.0.1. Everytime I run tool from SAGA or GRASS, I get exactly the same error, for example: Oooops! The following output layers could not be open Channel Network: /tmp/...
4
votes
1answer
366 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 ...
4
votes
0answers
252 views

SAGA Tool in QGIS Error: Load table: Proj.4-WKT Dictionary… failed

I have some problems with running SAGA tools in QGIS. I've downloaded and installed the software via the OSGeo4W Installer. It downloaded QGIS 2.12 and Saga 2.1.2. I wanted to use the Tool "Shapes To ...
4
votes
0answers
214 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 ...
4
votes
0answers
752 views

Problem loading output layer QGIS

Every time I run operations with temporary file output from the graphical modeler, I get the following error message: Oooops! The following output layers could not be open CLIP: C:\Users\Amine\...
3
votes
1answer
124 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 ...
3
votes
0answers
62 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 ...
3
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0answers
305 views

How to calculate the distances to outlet along the flow path ?

I have created these raster files for a river basin: DEM Flow Direction Flow Accumulation I like to genereate a layer how it is shown in the picture below. I need the values for the distances from ...
3
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0answers
461 views

Grid Error – Natural neighbour

I am getting the following Error on using Natural neighbour. There were solutions suggested here & here. But these works fine on Windows but not on Ubuntu. I am using Ubuntu 14.04, QGIS 2.18.4 &...
3
votes
0answers
151 views

Why is 'Line Dissolve' producing different output than 'Dissolve' from Ftools?

I'm curious if anyone can explain the strange effects I'm seeing from the SAGA 'Line Dissolve' tool. I have a ton of line features that had previously been 'exploded' (which is a necessary step), and ...
3
votes
0answers
770 views

Error on running Saga GIS inside QGIS

I have installed QGIS (2.14.3-Essen) along with SAGA GIS (Version: 2.2.7) in Ubuntu (14.04 trusty). I am trying to fill the sinks in a DEM in QGIS processing using SAGA provider. I have used both the ...
3
votes
0answers
346 views

Error with SAGA's Topgraphic Correction: Can't load requested DLL gdal_MrSID.dll

I am using QGIS 2.14.2, trying to perform a supervised classification on a rapideye image with the SCP plugin. To improve my classification im trying to work with the SAGA's topographic correction. I'...
3
votes
0answers
159 views

“Select a tool” error Saga: Accumulated cost (isotropic)

I'm trying to run Saga's accumulated cost operation in QGIS on a DEM and set of raster destination points, but keep receiving an "Error: select a tool" in the log after a failed run. There are no ...
3
votes
0answers
393 views

QGIS: How to create a crosstab using SAGA toolbox cross calssification and tabulation?

I am trying to use Cross classification and tabulation SAGA toolbox. I have a raster DEM file (14 classes) and raster file precipitation (13 classes). I want to do cross-tab - but I don't know how ...
3
votes
0answers
645 views

How to interpolate (ordinary kriging) large files with QGIS processing

I'm using the Saga ordinary kriging tool as apart of different processing models. The biggest issue I have is the very slow performance. My point shape files have mostly more than 200.00 points (some ...
3
votes
0answers
160 views

Raster calculators in SAGA return incorrect results

Here's a sample of my dataset (one cell) with 28 different raster values, representing 28 individual Float32 rasters with identical parameters. 0.0000264434, 0.0049953502, 0.0007529828, 0....
3
votes
0answers
279 views

Improve tree extraction method

I want to extract trees from a given normalized Digital Surface Model (nDSM) in SAGA GIS. My workflow is the following: Applying a Gaussian Filter to the nDSM with search radius with standard ...
3
votes
0answers
271 views

Error when using SAGA's “topographic correction” algorithm in QGIS

I'm trying to do topographic correction of Landsat images using SAGA's "topographic correction" algorithm from QGIS' processing toolbox. I was able to do it using Minnaert Correction with slope and ...
3
votes
0answers
943 views

how to orthogonalize building outlines

I'm looking for a way to orthogonalize building outlines which I've extracted from a high-res DEM. I'm using the FOSS GIS stack (QGIS, GRASS, SAGA, PostgrSQL, PostGIS) and can code in Python (or Java)....
3
votes
0answers
656 views

SAGA Raster Calculator, ifelse doesn't return specified value exactly

I am using the SAGA Raster Calculator in QGIS 2.6 to change NaN values to zero and that part is working great, however the specified 'if' value is being altered slightly. I have developed a work ...
3
votes
0answers
139 views

QGIS algorithms do not work on copies of shapefiles?

I'm using QGIS 2.6.0. I'm trying to run various algorithms such as "SAGA/Shapes-points/remove duplicates" & "SAGA/Shapes-Grid/Add grid values to points" through the sextant toolbox. When I run ...
3
votes
0answers
415 views

Extra row and column in a raster after GDAL grid import

I'm exporting an ESRI grid to TIFF format and after that I'm reading this exported raster file into SAGA GIS. However when Saga reads this file in there appears to be an additional row and column in ...
3
votes
0answers
278 views

MSHP file from SAGA tough to delete

After running a SAGA line dissolve process in QGIS, an MSHP file is created (amongst other things). Fine by me, though I'm not sure what it's used for (metadata in XML format?). Problem is that it can'...
3
votes
0answers
815 views

SAGA/GDAL fails to open grid in QGIS 2.0.1 on OSX 10.6.8

I want to try different grid/raster spline interpolation methods using SAGA in QGIS. I'm using the kyngchaos build 2.0.1-7 for Snow Leopard. Every SAGA algorithm I try gives the following in a popup: ...
3
votes
0answers
771 views

Watershed Segmentation SAGA-GIS

I'm trying to segment a topographic map to vectorize it. I'm using the watershed algorithm of SAGA-GIS. It's working fine with polygons, but with roads or contour lines is not working properly. Here ...
3
votes
0answers
809 views

Saga Reclassify grid problem

I am using Qgis 2.1 ver. 5f5cd4c (64 bit version on win7 64) OSGeo installed. I was trying to reclassify a DEM in EPSG:32614. I used the SAGA's Reclassify algorithm in the processing toolbox. I ...
2
votes
0answers
37 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 ...
2
votes
0answers
46 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. ...
2
votes
0answers
176 views

Empirical variogram plot in QGIS

I am trying to do kriging on mortality rates using QGIS (I have version 3.0 but I downloaded the 2.18.20 to be able to follow the web documentation and most of the answers here). From what I have ...
2
votes
0answers
206 views

Saga Catchment Area not giving expected (useful) output

I am identifying a catchment network from a DEM in QGIS3 (v3.0.3) (on a mac v10.13.4), however the step to identify the Catchment Area is not working. I have an input DEM, with layer CRS set to ...
2
votes
0answers
123 views

Saga clip raster with polygon missing cells entirely within the polygon

I am using SAGA's Clip Raster with polygon tool in QGIS 2.18.4. It is missing an entire row of cells which are entirely contained within the clipping polygon (see image, original DEM in colours, ...
2
votes
0answers
132 views

Add polygon attributes to points fails to create layer

I'm trying to add polygon attributes to a point file with a lot (~370,000) of points in QGIS v3.0.0. I first tried using the point sampling tool, which I've used with success pulling the values from ...
2
votes
0answers
93 views

While learning SAGA in QGIS, I get error. What is the reason?

I use QGIS3.0 in linux(ubuntu 16.06 LST). And whenever I try to use saga toolbox, I get some error like image. I select "save to temporary file". What is the reason? please help me.
2
votes
0answers
629 views

Multiple Linear Regression Analysis in QGIS (with SAGA Toolbox)

I'm attempting to run a multiple linear regression analysis using QGIS, through the SAGA toolbox. However, the QGIS UI does not allow me to choose predictors -- it seems entirely absent from the UI. ...
2
votes
0answers
288 views

Using SAGA and GRASS on macOS Sierra?

I am trying to run QGIS 2.18.13 on Mac OS Sierra (10.12.4), but I'm having problems with SAGA and GRASS, at least from processing. Here's what I did: Installed QGIS from brew, but ended up having ...
2
votes
0answers
368 views

SAGA Raster Mosaic Issue with output (projection/not showing)

I am trying to create a mosaic from a couple of georeferenced raster images (old aerial photos) using the SAGA mosaic raster layers function from the QGIS toolbox. Project and layers are all on the ...
2
votes
0answers
186 views

Use SAGA from within QGIS on mac osx

I am trying to use SAGA from within QGIS. I can run SAGA standalone, but not from within QGIS - nothing appears in the Processing Toolbox. I tried following Why is SAGA from the Processing Plugin ...
2
votes
0answers
225 views

SAGA Merge Vector Layers 'Add Source Information' not returning correctly

Running "Processing -> Toolbox -> Saga -> Merge vector layers" in QGIS with 'Add source information' checked returns a merged file with an additional attribute "Source" but the values are a series of ...
2
votes
0answers
217 views

How is ray tracing different from ambient occlusion when hillshading with SAGA?

SAGA offers both raytracing and ambient occlusion in its Analytical Hillshading module, but doesn't explain how these modes differ. Is one significantly more expensive in computation, and is the ...
2
votes
0answers
156 views

QGIS SAGA Raster Calculator returns incorrect results

The SAGA Raster Calculator within QGIS produces wrong results probably due to interpolation but works corretly withion SAGA itself. The problem has been discussed here before but sofar I have not ...
2
votes
0answers
51 views

Warning from SAGA when doing Topographic Corrections?

I am trying to use SAGA for topographic corrections for the first time, however I am getting a warning that says: data not in the same grid Can any one suggest ways of formatting the data (DEM and ...
2
votes
0answers
488 views

SAGA GIS work with python API error

I want to work with python API and SAGA GIS. I am very new with this work. The first step I find one module for example Slope, Aspect, Curvature and I take with right click one python script. python ...
2
votes
0answers
305 views

Dissolving polygons using SAGA leaves gaps?

I am new in using GIS and I'm having some problems in properly dissolving some polygons. In particular, I have a single layer with about 3,000 polygons (protected areas), some of which overlap (the ...
2
votes
0answers
694 views

SAGA Merge raster layers error

I have 198 tiles of a DEM from which I want to extract contour lines, but doing the operation 198 times is ungainly. I tried SAGA's Merge raster layers, but it stops into this error: Oooops! The ...
2
votes
0answers
287 views

SAGA GIS Channel network crash

So, i had this very weird bug while treating my dem data lately. I used SAGA to create flows channel networks on a dem i acquired a little while ago. Preprocessed it using sink route detection and ...
2
votes
0answers
153 views

Mosaic overlapping, irregular raster layers produces grid of NaN

I am trying to use the SAGA - Mosaic operator in QGIS 2.14.0 to mosaic two viewshed raster outputs I have. The viewsheds are irregularly shaped and overlap considerably, thus the need for the Mosaic ...
2
votes
0answers
73 views

Does SAGA in QGIS processing can support no ascii name?

From Qgis, I am calling through Processing the Saga algs "clipgridwithpolygon" raster_inside_poly = processing.runalg("saga:clipgridwithpolygon", my_raster_temp, ...
2
votes
0answers
603 views

Delineate watershed using manual points in RSAGA

I'm currently trying for an automated solution to delineate watersheds within a large basin. I have a collection of locations (X,Y coords) for various tributaries reaching a larger river, and the end-...