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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28 views

Use of QGIS/GRASS/SAGA procedures on Geometry Generator

Im new at QGIS, started 2 weeks ago. I'm trying to automatize the display of a map and get rid of some "duplicated" layers and all the extra work. I need to know if SAGA's dissolve can be used in the ...
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48 views

Classification result from SAGA GIS shifted by 5 meters if used in ArcMap?

I use a band composite of 10 Sentinel-2 bands for my classifications. If I use the same composite in SAGA to make a classification this classification result is shifted by 5 meters to the left and to ...
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33 views

Least Cost Path in QGIS: Plugin or SAGA or GRASS?

I downloaded a SRTM file and followed this tutorial and now I have a hillshade layer and a color layer. It looks like this. I want to calculate the least cost path between p1 and p2. But I'm not ...
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1answer
26 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
47 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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40 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/...
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1answer
39 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
32 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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33 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
73 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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78 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 ...
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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
57 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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57 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. ...
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1answer
202 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 ...
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31 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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1answer
73 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 ...
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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 ...
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1answer
97 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 ...
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3answers
116 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 ...
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68 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
90 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 ...
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62 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
99 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 ...
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1answer
80 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 ...
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1answer
78 views

Relief Segmentation Tools, SAGA

Where can I find documentation on the tool Relief Segmentation of the library Terrain Analysis?
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2answers
156 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 (...
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0answers
50 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 ...
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1answer
396 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....
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106 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 ...
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1answer
171 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.
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1answer
49 views

Piping one SAGA Raster Calculator output into another chaining algorithms in QGIS processing script?

I am using QGIS 2.18.15. I want to streamline multiple SAGA raster calculator calculations using the output of one calculation (not loading it into the table of contents) as input raster for the ...
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1answer
119 views

SAGA Raster Calculator in QGIS Algorithm script produces 'NoneType' object has no attribute 'crs'

I would like to produce a new temporary raster after a calculation with the SAGA raster calculator using a custom python algorithm script. This is my code so far: ##MaechtigkeitunterhalbeinerHoehe=...
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1answer
336 views

Layers not correctly generated using saga algorithms within QGIS 3.4.4-Madeira

I am trying to use a few algorithms that may be useful for my work, that are part of the processing tools packaged with the latest LTR 64-bit version of QGIS in Windows 10 64 bit.. However, all of the ...
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1answer
29 views

SAGA Raster Calculator processing script give error “name 'Rasterout' is not defined”

I am trying to build a custom script using things I have learned from this post: Number inputs as raster calculator variables in QGIS Modeler This is my script so far: ##Maechtigkeit unterhalb einer ...
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71 views

How to write raster in saga format with python

I try to write a raster file in SAGA GIS format (sgrd). My script is work but some information is missing in the final file (i.e output.sgrd). Here is script : from osgeo import gdal, ogr, osr import ...
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43 views

Radiometric correction of Aster Level 1T

We have to mosaic 70+ ASTER Level 1T imageries. I've splitted hdf data into 14 different tif's (3 VNIR, 6 SWIR, 5 TIR). As shown in the image imageries are of different time period. Question is, is ...
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24 views

Making QGIS model that iteratively creates several constant grids at once?

I'm looking to calculate the volume of a virtual reservoir from a DEM. I would use a constant grid (SAGA) to represent the ceiling, and I want to see the change in volume for each 1 metre interval. So ...
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64 views

Calculating maximum extent of debris flow from point with mean slope value

At a very large scale I perform a spatial analysis for which I have to apply mean slope criteria. These criteria allow me to calculate the maximum extent of an event (debris flow). I know that below a ...
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1answer
137 views

Using SAGA GIS for TPI classification?

I processed one country with TPI, and I got a certain Landforms classification of terrain. (Topographic Position Index (TPI) calculation as proposed by Guisan et al. (1999)). When I processed only one ...
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1answer
135 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' ...
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1answer
182 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
51 views

How to connect polygons to make a circle?

I created polygons from a raster on which I ran an edge detection filter. I turned the edges into a polygon layer (multipart splitted into single parts). The intention was to have circular polygons at ...
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54 views

SAGA_cmd crashes (using RSAGA)

I'm using SAGA-GIS to compute some terrain attributes with a DEM of file size 3.52 GB. I use Rsaga to operate on a 64 Bit operating system with an Intel(R) Core(TM) i5-2400 CPU @ 3.10 GHz Processor, ...
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1answer
39 views

How to add multiple layers to SAGA map view at the same time?

I need to visually interpret more than 50 grids, so I want to add them all to a SAGA map at the same time. If I right-click on a single layer, I can "Add to Map", but with multiple, this option is not ...
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125 views

Problems with SAGA on QGIS

I'm trying to perform an interpolation on SAGA in QGIS but every time I ran the tool (or any other SAGA tool for that matter) I got the following message: "The following layers were not correctly ...
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0answers
208 views

Error when running SAGA interpolation

I am running the nearest neighbour algorithm in QGIS 3.4.3. I have tried various parameters but the problem persists. I have also tried other algorithms (simple Kriging) and had the same problem. ...
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1answer
100 views

RSAGA error using rsaga.pisr2

I just downloaded SAGA and the RSAGA package for R. I would like to use the rsaga.pisr2 function to compute solar radiation for my region of interest. I am currently getting errors related to proj4 (...
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1answer
62 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. ...