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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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
552 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
421 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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542 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
530 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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389 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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82 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
369 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 "...
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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
215 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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200 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
213 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
122 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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112 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
550 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
471 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
134 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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227 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
260 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
228 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
180 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 ...
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1answer
222 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
390 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.
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1answer
743 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
102 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 ...
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1answer
198 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
254 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
631 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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313 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
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 &...
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1answer
182 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)) * (...
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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 ...
5
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2answers
564 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
706 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
235 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 ...
2
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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 ...
3
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2answers
835 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 (...
3
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1answer
319 views

DEM classified using SAGA GIS and conversion to point shape

I have converted DEM to terrain specific points i.e. peaks, pits, saddle points etc. with SAGA GIS using surface specific points tools. The output is showing values as 1, 7, 9 -1 etc; with different ...
5
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1answer
6k views

Saga-GIS Mosaic raster layers error: 'NoneType' object has no attribute 'crs'

Trying to merge multiple raster layers (TIFF's) with the same extent with Saga-GIS Mosaic raster layers. The only reason I'm using this Mosiac-thing is because it lets me merge multiple layers (...
5
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2answers
2k views

How to configure QGIS (SAGA, GRASS algorithms) in Ubuntu

I have installed GRASS GIS following this install manual. I have installed SAGA GIS following this install manual. and finally I have installed QGIS 2.18.1 following the official details for ...
4
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1answer
897 views

SAGA grid tools missing in QGIS

Grid options are missing in SAGA toolbox. If I go to options in processing the following message is being displayed. How should I change the path?
5
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1answer
78 views

Why “saga:gridssum” takes 7 input grids instead of 3?

I want to sum the cell values from 3 grids. I have a list of file paths (temp layers) generated in a "for" loop, looking like the following one. I cannot understand why the function makes some ...
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93 views

How to do regression analysis in SAGA for topographic correction

Currently I am trying to do the topographic correction using C-Correction. I would like to know if there is a way to do the regression analysis between L (uncorrected reflectance of each band from ...
6
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1answer
761 views

Flow Path length

I'm a student and pretty much new to QGIS, GRASS and SAGA tools. I'm trying to calculate the longest flow path length using SAGA "flow path length" module in Qgis. Using the default parameters: I'...
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1answer
79 views

How to sum values of a grid moving upstream along flow paths in GIS/R?

I would like to sum the values of a grid, moving upstream along flow paths. In other words, I have a grid A with a value for each cell. I need to build a new grid, B, in which the value of each cell ...
4
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1answer
742 views

Color palette SAGA GIS

Does anyone knows if it is possible to manually modify SAGA GIS colour palettes, for example using ColorBrewer references?
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82 views

QGIS mac: Problem running several algorithms from toolbox

I want to use the SAGA algorithm "add coordinates to points", but I get an error message: Algorithmus Add coordinates to points startet... shapes_points "Add Coordinates to points" -INPUT "/var/...
3
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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 ...