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
379 views

SAGA command line not working

I'm trying to script a reclassification using SAGA Grid_Tools-Reclassify Grid Values tool but I'm having the error: Reclassify Grid Values: could not initialize data objects. I've tried different ...
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1answer
208 views

DEM, points values and elevation to create a map of temeperature

I am using SAGA - Universal Kriging (Global) for this, but I am stucked. I have grid (.tif) for Serbia with elevation values, and .shp file with points that have mean yearly temperature. I want to ...
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0answers
408 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 ...
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1answer
548 views

Delineating coastal subbasins using SAGA GIS or GRASS in QGIS?

I'm having some problems trying to delineate watersheds using the SAGA watershed delineation tools in QGIS. I have a SRTM DEM (cell size 30 m) which I set the water cells to NULL values, following ...
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0answers
195 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 ...
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1answer
480 views

Using Raster calculator SAGA PyQGIS

I'm trying to plus two raster images through the python interface of QGIS, i want to use the saga raster calculator, but i got one error but i don't know why: i'm doing the following calculation (the ...
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1answer
619 views

SAGA tools not working in QGIS 2.18

I've only just started using QGIS (done some things in ArcGIS before) and SAGA tools don't work. The results don't make sense, QGIS stops answering or there is a python error. Could it be that there ...
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2answers
914 views

SAGA GIS, how to generate groundwater contour lines from points?

I'm trying to generate contour lines/isolines from groundwater points (groundwater depth) with SAGA (I tried before with QGIS, contour plugin, but the result was not good looking, too angular lines). ...
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2answers
839 views

QGIS: Saga Channel network: how to prepare SRTM data

I am trying to use the Saga toolbox (2.2.3) in QGIS (2.18) to create a channel network from SRTM data using this tutorial 1. It works, but the result I get when using the DEM that comes with the ...
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1answer
127 views

Slope Aspect Curvature algorithm giving error

I am trying to execute the slope aspect curvature algorithm in QGIS using a stand-alone script. When I run this code, I am getting a 'problem executing algorithm' error, which occurs when trying to ...
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1answer
419 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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1answer
1k views

Add raster value to features AttributeError: 'module' object has no attribute 'TYPE_RASTER'?

When I try to run the "add raster value to features" (available into SAGA Tools), I get this error: Traceback (most recent call last): File "/usr/share/qgis/python/plugins/processing/gui/...
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2answers
599 views

Error in raster Analysis in QGIS

I'm trying to conduct raster analysis in QGIS on a digital elevation model with a grid resolution of 5 cm. The disk size for the data set is 151 MB. When using default GDAL raster calculator it throws ...
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1answer
475 views

Method of multiple values - Rasterize SAGA

I'm converting a thematic shapefile (polygons) into a raster file using the Rasterize-SAGA algorithm. What criteria should I use to decide for [0] last, [1] first, [2] minimum, [3] maximum, [4] mean ...
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1answer
562 views

Which SAGA versions does QGIS 2.18.10 support?

Beginning with QGIS 2.18.10 the SagaAlgorithmProvider do not longer have a dictionary called supportedVersions. Previously, it looked like this: supportedVersions = {"2.1.2": ("2.1.2", ...
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2answers
619 views

Get values of terrain elevation of roads in QGIS?

I have one DEM raster layer with elevation values and one vector layer of the roads; same size, extension and CRS. I want to do what this guy did here: http://youarealegend.blogspot.de/2012/07/...
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1answer
446 views

How to add a WMS in SAGA GIS

This question seems simple but I couldn't get it done for most of the layers I tested: This is the adress that is predefined. It works with a small subset ogc.bgs.ac.uk/cgi-bin/...
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85 views

Copying coordinate system and extent from a TIFF to a polygon shapefile in SAGA GIS

I used R to batch process object based image segmentation on some geoTIFF files using rgdal to communicate with SAGA GIS. I got the resulting shapefiles, all with the following properties: Projection ...
2
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1answer
395 views

How to make ordinary krigging with a spherical variogram in SAGA GIS?

I have a very special map to make: it's a sea bird density map. To do this, I interpolate the observation points with ordinary kriging with a variogram. As I've read, the variogram must be of "...
3
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1answer
1k views

SAGA grid tools not found on QGis 2.14.15

I am missing all grid tools from SAGA in QGis 2.14.15. I know it's a question that has been asked before (there : SAGA grid tools missing in QGIS ) but unfortuately the answer given in this post did ...
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1answer
225 views

Using SAGA reclassification with tabled categories in QGIS script

I am using QGIS, and I would like to write a script to help processing the data. To do so, I have to reclassify heights values from a raster. I have written the following code, where retab is the ...
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0answers
211 views

“Unknown option 'CAREA'” in SAGA Catchment area algorithm for QGIS

18.7 version ans I try to use SAGA algorithm Catchment area and I take Unexpected error because that algorithm look easy. I test with the different raster layer and the some error. Maybe I have ...
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1answer
234 views

How to extract planting lines from a raster image?

I have a high quality drone image and I want to remove the soil and leave only the planting line.So far already able to classify the images leaving 1 for the plantations and 0 for the soil, it is a ...
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0answers
140 views

Calling SAGA modules through GRASS run_command in a script PYTHON

Does someone have an experience|example of calling modules of SAGA with the grass.run_command method in a script written in PYTHON?
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116 views

Saga GIS at command line in OSGeo4W - 'shapes to grid' tool - sqlite input

I have been using the Saga 'Rasterize' plugin in QGIS to rasterize spatial data from sqlite format (road networks, and intersections) to tiff. I find this tool more flexible than the gdal_rasterize ...
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1answer
597 views

Replacing 0 values of a raster with values from another raster in QGIS?

What I want to do is pretty straight forward: I have two raster with the same crs, resolution and extent. Both rasters show the number of days an area is flooded so they just have two values. Raster a ...
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1answer
530 views

Methods in Slope, Aspect SAGA calculations

Using this algorithm in QGIS I can choose between 7 methods, the default one being by Zevenbergen & Thorne 1987. What's the difference between them and can I just use the default one without ...
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1answer
140 views

Making DEM raster file using centroid point shapefile in QGIS? [closed]

I had a DEM file at first. Then I converted it to centroid points vector to add some data to it. So, I ended up with a vector with millions of points. Now I added my data and I want to use "elevation" ...
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0answers
250 views

Analytical Hierarchy Process (AHP) tool: Input layers do not have same grid extent [duplicate]

I am using this tool to create a suitability map for landfill site selection. However, when I gave the input raster layers, the .csv file for comparison table and run the tool, an error message saying-...
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2answers
268 views

Determining best neighbourhood search radius for Topographic Position Index (TPI) for predictive soil mapping?

I'm not sure how to determine the best input values for a search radius to create a TPI for the purpose of predictive soil mapping. Would this depend on the spatial extent of the area I wish to map?...
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2answers
235 views

Reclassify Slope using SAGA Raster Calculator

I am looking for the right formula for reclassifying a slope raster. I need to switch the values 1 = bad, 10 = good to 1 = good, 10 = bad. This Formula worked fine using the normal raster calculator: ...
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1answer
209 views

How to fix unusual initial DEM input values and derivative raster output values in SAGA GIS without rescaling?

I am trying to run elevation derivative tools on a provincial DEM provided by the Ontario Government website (Ministry of Natural Resources and Forestry) and I am getting strange values when bringing ...
2
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1answer
239 views

How would I determine my search radius when conducting a Topographic Position Index in SAGA GIS?

When running the TPI tool in SAGA, I get this parameter-entry window: Under the section highlighted in the red box, what do these parameters mean? Do the search/neighbourhood grouping parameters mean ...
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1answer
420 views

Creating Topographic Position Index in SAGA GIS?

I am trying to create a TPI from a DEM tiff file in SAGA but keep getting the following result: I'm just not sure what I'm doing wrong.
2
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1answer
871 views

SAGA Gaussian filter lower value than 1?

I'm smoothing a 2 meter DEM using the Gaussian filter in SAGA through QGIS/Processing and the smallest amount for the smoothing of the Standard Deviation value of 1 which for me is too much, it all ...
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0answers
103 views

Problems with weighted overlay on QGIS for Mac

I am a beginner on GIS seeking to finish a suitability analysis. For this I was planning to use 'vector to raster' tools as well as a 'weighted overlay analysis' to find the most suitable areas. I ...
2
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1answer
230 views

Importing raster in the same resolution/extent in SAGA

I'm using the Imcorr-Feature tracking in SAGA GIS for comparing displacements on orthoimages and DSM. Every raster has to have exactly the same number of cells and map extent. This is where i'm ...
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1answer
278 views

QGIS/SAGA Cross-tabulation error

I'm new to QGIS after using ESRI/ENVI/ERDAS products for years. I am trying calculate a cross-tabulated change image for post-classification change detection. After figuring out how to fix a ...
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1answer
678 views

How to add attributes from polygon layer to point layer when layers have different projections

I have two layers in different coordinate systems: polygon layer with catchment areas and names of the catchments (EPSG 21781) point layer with coordinates and flood flows (EPSG 2056) They of ...
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0answers
359 views

How to show and access SAGA not shown in Processing Panel in QGIS 2.18.4? [closed]

How to get SAGA modules to show and be usable within QGIS, i.e. from within the Processing Panel? I have tried reinstalling SAGA (now = Version: 2.1.2 64 bit) through the OSGEO4w installer and tried ...
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0answers
482 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 &...
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1answer
193 views

Rename outputs from QGIS processing saga algorithms

I have a processing script which chains together several saga processing tools like this: outputs_SAGARASTERCALCULATOR_3=processing.runalg('saga:rastercalculator', inputvx,[inputvy],'(atan2(a,b)) * (...
6
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2answers
1k views

Estimation of volume from DTM

I'm using QGIS for quite a while now but I'm having some problems in measuring the volume of a depression zoned North of a waste dump I'm studying. For the analysis I'm using a recent 1mx1m DTM of ...
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2answers
612 views

Add Polygon Attributes to Points error QGIS

I am trying to run the Add Polygon Attributes to Points algorithm from the Processing Toolbox in QGIS but I run into an error. All my points are either inside the polygon or exactly on the border. I ...
4
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1answer
798 views

Which interpolation method is used in the close gaps module of Saga GIS?

I like to close gaps in a raster layer using the Module Close Gaps of Saga. I can not find which interpolation method is used by the module. Which method is used by the module and/or where can I find ...
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2answers
245 views

SAGA error (Segmentation fault) with running QGIS

--Running with configuration is Mac OS X 10.11.6 (El Capitan), QGIS 2.14.7-Essen, SAGA 2.2.3-- I'm hoping that someone knows what the fix is for the failure I'm encountering in the SAGA tool. I'm ...
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0answers
241 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 ...
3
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2answers
877 views

QGIS Sample Points From Raster

I know that QGIS can add values from a raster to a set of points on top of the raster through the SAGA "Add raster values to points" tool. However, I would like to generate the points themselves based ...
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 ...
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5answers
3k views

Problem getting SAGA activated in Ubuntu QGIS 2.18.2

By some reason SAGA does not appear into Processing Toolbox list although I have checked it to be active. See screen capture. What could be the problem? QGIS vesion is 2.18.2 and OS is Ubuntu 16.04 (...