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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NDVI Workflow Problems, Red Channel Seems High Causing Low NDVI value?

I did some searching but nothing came up around this. I'm trying to verify a workflow from images to an NDVI to verify I have a basic workflow correct. Process images example dataset through ...
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2answers
172 views

How to sum values of overlapped pixels in thousands of rasters layers and clip it using a polygon in QGIS?

I have a lot of rasters files (more than 6000), each one represents the presence and absence of a species (1 for presence and NoData for absence). The set of rasters covers the whole Latin America ...
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192 views

SAGA version with QGIS 2.10

I want to know which version of SAGA is used with QGIS 2.10. I developed a standalone application which uses QGIS inside. I have problems using SAGA algorithms. SAGA is well installed but I found that ...
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110 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 ...
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2answers
315 views

Does Processing plugin v2.10.1 not recognise SAGA?

Version 2.9.3 of the Processing plugin works fine, I can run the SAGA tools successfully. Updating the Processing plugin to version 2.10.1 results in SAGA disappearing entirely from the toolbox. The ...
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337 views

SAGA tool 'Relative Heights and Slope Positions' - What do results tell me?

I am currently trying to get in morphometry, using the SRTM 30m DEM. I was recommended to test the SAGA mudule 'Relative Heights and Slope Positions' ...
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79 views

QQIG/SAGA “merge shapes layers” algorithm removes underscores/pluses from layer names

I have a bunch of layers that are named layername_number+number that I want to merge. I need their names as source attribute so I used the "merge shapes layers" algorithm found under SAGA in the ...
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86 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 ...
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2answers
334 views

Why is SAGA from the Processing Plugin not recognised?

Similar to this post: SAGA algorithms don't work in QGIS 2.8 except the fact that SAGA does not appear at all in the Processing Toolbox: As a check, I used the Python Console with the following ...
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45 views

Hydrology Analysis via SAGA - what is the unit? [closed]

I did a couple of analysis via SAGA about an area in Iceland...I've never worked with SAGA before, could anyone tell me what Units the numbers in the legends for "Catchment Area Recursive" and ...
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120 views

From DEM to Topographic Wetness Index in SAGA GIS

I have DEM in GeoTIFF format and I wish to calculate Topographic Wetness Index in SAGA GIS. TWI tool in SAGA GIS expects that user provides two values - 'slope' and 'catchment area'. Since there's ...
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66 views

GRASS and SAGA CentOS Linux release 7.1.1503 (Core)

I have a problem. I am developing a standalone app using QGIS but my script imports GRASS nad SAGA plugins and I have error to create the maps. I have CentOS Linux release 7.1.1503 (Core). SAGA is ...
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82 views

Why does the “local maxima” module in SAGA GIS put so many “maxima” points on lakes and plains?

SAGA GIS puts too many maxima points on plains and lakes. Why does it happen? Is there a way to avoid this? It's not really a big problem (the value is correct) except for the size of the SHP files in ...
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1answer
521 views

SAGA algorithms don't work in QGIS 2.8

when I have installed recently QGIS 2.8 and, since then, SAGA algorithms don't work. Apparently, the algorithm runs well (any error is showed while it is executing the algorithm), however, there is ...
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2answers
355 views

how to add multiple grids in SAGA gis

Here is the "big" problem: my Digital elevation model is divided in a lot of pieces (single files .xyz). In order to build a mosaic of them I need to import them all. With SAGA I can import them ...
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114 views

Why is SAGA kriging slower in QGIS than in SAGA itself?

I'm using QGIS for a while. In my opinion the SAGA kriging tool (processing toolbox) is very slow. Is that an QGIS issue? I tried to interpolate a point layer with 300.000 points (I know it is big) ...
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134 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.
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112 views

Put output of SAGA algorithm of Processing model in R script

I'm trying to combine the Variogram Cloud model of SAGA with an R script inside a Processing model. First, the R script is: ##Vector processing=group ##showplots ##Layer=table ##X=Field Layer ...
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1answer
136 views

View feature space for multi-band files

I am trying to plot a feature space (scatter plot) for some SPOT images in QGIS 2.8.1. I know a histogram is available in the file properties, but I want to plot eg. Band 1 vs Band 2 to see the ...
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24 views

Generating a plot by varying the buffer around each point

I want to create a plot like this: Basically, I have a bunch of points (properties), some of which have (and some of which don't) have Property X (e.g., a fence). I want to find out how the ...
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73 views

Is there a list of Open Source tool alternatives for ArcGIS tools? [duplicate]

Is there any place one can find a list of ArcGIS alternative or near-alternative tools found in (any of) the open source softwares? I am not looking for software but individual tools found in the ...
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1answer
565 views

QGIS SAGA Raster Calculator [closed]

I am using SAGA --> Grid Calculus --> Raster Calculator on QGIS version 2.6. The formula I am using is: ifelse(gt(a,0), (a), b) where a is my layer with values in a greater extent than that of b. ...
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218 views

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

First time caller, long time listener.... 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 ...
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1answer
855 views

Unsupervised classification in QGIS

I was trying to learn unsupervised classification in QGIS 2.6 following the tutorial video: https://www.youtube.com/watch?v=mI80eENtWSE When trying myself, clicked Run during the process it shows the ...
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1answer
179 views

Can't import libraries to rsaga

I get this error when I'm trying to import a raster to RSAGA: > rsaga.import.gdal(paste(rast_name, ".tif", sep=""),"RASTER", env= my_env) Module 'GDAL: Import Raster' not found in SAGA library ...
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67 views

How to load “soil types” in QGis?

I want to show soil transmissivity per pixel. Thus, I determine water holding capacity of each pixel (ignored other effective parameters). Respectively, I wonder, What is the soil data format and How ...
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3answers
1k views

SAGA installation in QGIS 2.8 on debian linux

I install QGIS 2.8 in debian (linux) through nightly jessie (qgis testing) and I see that SAGA is not in processing toolbox, so I install saga gis software but still it doesn't appear in processing. ...
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1answer
368 views

How to calculate “water accumulated in each cell” using QGis?

I create channel network and catchment area from a DEM with SAGA GIS. I know that flow is starting from a cell to an other cell. Firstly, a cell is filled with water and then it is starting to flow ...
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2answers
71 views

Representation of precipitation data

I have an excel sheet of precipitation data of each month of some districts. I have also the shapefiles of these districts. How can I represent this data in these shapefiles.
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1answer
340 views

setting SAGA folder for QGIS with OS X macports install

I am trying to get the toolbox to work in QGIS 2.6, but I keep getting an error message that SAGA is not properly configured. After much digging, I finally found I can set the SAGA folder in ...
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112 views

SAGA GIS - raster image from Civil 3D

I am a new user of SAGA GIS software. I need to interface the Civil 3D 2015 and Hec Ras software in order to create a flooding map. In order to put in communication the two softwares, I have to use ...
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56 views

What is the background processing of rainfall thresholding?

I want to create a flood map using Quantum GIS. First of all I create catchment area (flow accumulation). Then, I delineate a Channel Network by applying a threshold to flow accumulation. So I want to ...
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145 views

QGIS 2.6 SAGA Processing Algorithm, “Add grid values to shapes”, produces NULL Values

I'm using QGIS 2.6 Brighton on Windows with SAGA 2.0.8 installed using OSGeo4W. I have the same versions installed on OSX as well which is not having this problem. On Windows, I'm trying to extract ...
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151 views

How to calculate the Vertical Distance to Channel Network in ArcGis?

In Saga there is the tool "Vertical Distance to Channel Network". Is there a way to produce the same data in ArcGIs? With con("flowacc" > xx, 1) I was able to create the Channel Network. I am ...
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1answer
97 views

How to read .asc format DEMs that have headers with #comments

I have around twenty 2 GB DEMs (xyz) in .asc format. The header has 13 lines of metadata, and then the basic data in three columns # # The DTM grid had lower left (southwest) corner coords: # X ...
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1answer
272 views

saga_gui.exe identified as malware by antivirus when downloaded from OSGeo4W [closed]

I downloaded QGIS 2.6.1-2 (Brighton) yesterday from OSGeo4W-setup-x86.exe using the advanced installation option on a machine running on windows 7 professional. The download worked Ok except for saga ...
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1answer
101 views

Saga:processing resample extent in python editor QGIS

I would like to resample many geotiff layers to another geotiff layer's extent and pixel size. For this I would like to use the QGIS python console (editor). When I run my script it raises the ...
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1answer
142 views

Fill polygons via data-defined pie charts

I am trying to summarize my polygons by each's distribution of some variable. To couch the discussion, let's say we wanted to summarize the demographics of each county (of a small state) by it's ...
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99 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
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1answer
162 views

How to remove spikes from grid in SAGA GIS? [duplicate]

I tried to get a grid by interpolating LAS file using Ordinary Kriging. But the product grid has many pixels which values strongly stands out from average surface - I mean one pixel sinks nad spikes. ...
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129 views

Problems using the SAGA in processing framework with qgis 2.6.1 (ubuntu) [closed]

I've got problems using saga in the processing framework within qgis 2.6.1 and SAGA 2.1.4 To solve this problem I was obliged to correct the line 352 of the python file ...
3
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0answers
304 views

SAGA is not working within sextante (QGIS processing installed in Ubuntu)

Recently i decided to start working in Ubuntu (version 14.04). My first step was to add the ubuntugis-unestable repository, and then proceed to install SAGA, GRASS, OTB, QGIS and the bindings between ...
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0answers
120 views

Batch raster calculation of slope and aspect in SAGA

I am relatively new to the SAGA software, I have only used it for small amouns of data, and for basic calculations. My data is obtained by mapping certain areas in GoogleEarth, then, overlaying the ...
3
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1answer
787 views

Orfeo tool box (OTB) in Ubuntu 14.04 and SAGA incompatibility (gdal versions)

I need to test segmentation of a 12000 x 12000 pixels scene. I successfully compiled OTB in Ubuntu 14.04 and ran the process. But when I tried to start SAGA, I got a startup error. I found that gdal ...
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546 views

QGIS SAGA Channel network error: Input layers do not have the same grid extent

I am trying to follow along with this exercise using my own DEM. I have done the first step, creating the catchment area, with no trouble. When I try to run the Channel network algorithm, however, I ...
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1answer
102 views

best algorithm to trace stream network in flat areas

i want to ask you what method do you suggest me for to trace stream network in flat areas and please explain me how to deal with the previous preapration of the DEM regards many thanks
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47 views

saga:slopeaspect curvature

I'm using windows 7 on 64 bit and using Qgis 2.6.0.I'm trying to process some Tifs from the console using the processing toolbox and saga:slopeaspectcurvature. This is pretty much how my code looks ...
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3answers
184 views

How to narrow raster features to single cell width?

Are there any tools or existing workflow which convert raster features (such as roads, rivers, electric lines etc.) which are (or can be) multiple cells wide to a single cell widht (i.e, center line). ...
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1answer
190 views

SAGA Cluster Analysis for grids projection issue

I am having an issue with the SAGA cluster analysis for grids tool within QGIS 2.4. I am actually taking this as an online class through Del Mar and we are going over supervised and unsupervised ...
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3answers
189 views

Find coordinates of given raster value

I would like to get the coordinates of a raster cell with a given value. I suppose many cells can take the same value, in which case several coordinates should be returned. In my first problem I'm ...