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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14 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
3k views

Convert a shapefile with northing/easting to ASCII raster with latitude/longitude

Linked below is a polygon shapefile whose projection is NAD83 and whose values are LU/LC codes. Coordinates are meters of northing and easting. I would like to convert it to an ASCII raster with ...
2
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1answer
36 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 ...
3
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1answer
427 views

How to build a confusion matrix for image classification using SAGA or QGIS?

I did a supervised classification of a Landsat image subset using my training data polygons. I used SAGA GIS for that and everything worked out fine. Now I am stuck since I have no clue how to ...
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0answers
24 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
534 views

Calculating longest flow path and avg. slopes for catchments with qgis?

I am a hydrologist and their are 2 important pieces of information I need for modeling. I need to know the longest flow path for each sub catchment in my area of interest and I need to know the ...
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1answer
110 views

(R)SAGA: saga_cmd 2.1.0 error? inconsistency?

frequently I am using (R)SAGA, but after SAGA became >2.1.0 the R package is no longer working. The last update for RSAGA was 07/2013. Thus I downgraded SAGA to 2.1.0 (first try was skipping the ppa ...
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1answer
30 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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16 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 ...
4
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1answer
68 views

What are definitions of watershed segmentation, local maxima, variable window search, regarding LiDAR for vegetation?

I am not familiar about Lidar. I want to measure trees height and number of trees. I guess, watershed = to locate the trees, local maxima = to measure trees height. I used these methods in SAGA GIS. ...
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3answers
39 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). ...
3
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1answer
35 views

How to export data from saga or tas into excel?

I want to derive terrain attributes from DEM with saga and whiteBox GAT (SAT). I have problem in exporting data into excel. would you help me?
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15 views

Calculation of RMS between two grids [duplicate]

I want to calculate the RMSE of two grids based on their z-value: a calculated and a reference grid. I do have the statistics: Cells, Range, Min, Max, Sum, Mean, Variance, St.dev. How could I solve ...
0
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1answer
34 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 ...
7
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4answers
6k views

How to calculate raster statistics for polygons?

how can I calculate sums, averages etc of raster-points (multi-band) per polygon of a vector-layer. I was told that this is called "zonal statistics". I tried that with QGIS first. There is a way to ...
2
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2answers
54 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 ...
4
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1answer
102 views

Why are my calls to SAGA routines in QGIS not working cross platform?

The ability to write and run cross platform scripts for QGIS using python is OUTSTANDING! However, when I try to run the SAGA:MERGESHAPESLAYERS algorithm from a python script it works fine in windows ...
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0answers
41 views

Issues with reclassify for QGIS Saga Reclassify Grid Values tool

I am trying to reclassify a raster using the Saga Reclassify grid values tool in the QGIS Processing Toolbox, but am getting an unexpected entirely black raster. I have verified my original points and ...
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0answers
57 views

QGIS Upslope/Downstream Areas

I am trying to locate areas upstream and downstream of a point of interest in QGIS in order to determine possible areas of origin upstream and areas of impact downstream. I have used a DEM to create ...
4
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4answers
167 views

Create a rectangular buffer from point shapefile using QGIS/GRASS/SAGA GIS/R

I have a points shapefile and I want to create a rectangular buffer (22 x 16 km) around each point. My goal is to create a 16x22 km grid where each of the points is the centroid of the grid. Seed the ...
6
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1answer
722 views

How to configure QGIS and SAGA on Ubuntu (12.04 and others)?

During the past weeks, I have tried QGIS to recognize SAGA via the processing toolbox, both being installed from the ubuntugis-unstable repository. I have tried this on several virtual ubuntu ...
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2answers
2k views

Efficiency of python script using SAGA and arcpy

=== SUMMARY === I have created a process to import a LAS point cloud, clip it, select the ground points and save the output as an XYZ.txt for clients to use. This uses a python based script (will ...
4
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3answers
223 views

LiDAR data density, returns per square meter

How can I compute a raster showing the number of return points per square meter using SAGA GIS or other open source software? My goal is to obtain a mask which would show me the places (cells) ...
2
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2answers
261 views

Exporting 16 bit single-band to 8 bit in SAGA/QGIS

Everytime with every function (e.g convert data storage type or gdal-translat -ot Byte) the output is a completely white map with a black border. only the "save as" export works, but the TIFF also ...
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1answer
62 views

Exporting 16 bit single-band to 8 bit in SAGA

Is there any possibility exporting 16 bit single-bands to 8 bit like in qgis (gdal_translate)? Additionally in SAGA there is no option to save raster with rendering, right?
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150 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: ...
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0answers
56 views

QGIS processing framework SAGA NaturalNeighbor in external Python Script - No Output

I want to build a little script, which generates a NaturalNeighbor grid based on a point Shapefile. The script runs within my PyDev environment without any error messages, but no outputfile is ...
3
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1answer
157 views

Topographic Index - Why is upslope contributing area divided by downslope contour width and not upslope contour width?

In the Topographic Index calculation, a is the upslope contributing area per unit contour length. Is the "unit contour length" calculated from examining the contour widths of the downslope cells that ...
2
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1answer
150 views

Negative Topographic Index Values

I am getting negative topographic index wetness values in SAGA GIS - anyone else every get this? Not all negative values, but the minimum of the TWI range is negative for some steep watersheds we are ...
3
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1answer
72 views

Underwater terrain modeling

My task is to model the surface of a lake bed, calculate volume of it and visualize it as 3D a surface. I have acquired depth measurements in a small lake using echosounder. The precision should be ...
3
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3answers
181 views

Fast and robust open source portable script or tool for interpolation - triangulation or similar

I am looking for some fast and robust open source interpolation library/script/tool. The goal is to re-interpolate relatively big (1M+ points) unstructured (xyz) grids into high resolution cartesian ...
0
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1answer
213 views

QGIS Processing error with SAGA, “output layer could not be open”

QGIS 2.4.0 SAGA GIS 2.0.8 DESCRIPTION ERROR when processing with SAGA. I used the "Shapes to Grid" function. The error given: "Oooops! The following output layers could not be open". This error ...
5
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1answer
203 views

Interactively determining upslope and downslope areas on DEM?

I know SAGA GIS can be used to interactively generate maps of upslope and downslope areas for a cell within a DEM, but the output is pretty ugly. An upslope area is defined as all cells (for a ...
1
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1answer
236 views

catchment area using SAGA and Arcgis 10.2

I would like to calculate catchment area. I used D8 algorithm and running in both arcgis 10.2 and SAGA GIS 2.1.2. However, the results from two software are different. The lowest value of catchment ...
0
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1answer
51 views

removing spurious lines in raster before or after vector conversion?

I'm looking for a feature/function in either python opencv/ndimage/gdal/etc. or qgis/saga/grass that will help clean up a skeletonized image that I'd like to vectorize into a shapefile of ...
2
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0answers
418 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: ...
1
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1answer
47 views

Rasterizing vectors in SAGA via saga_cmd - how to set the exact cellsize, extent (basicly grid system) based on other grid?

I'm doing some batch analysis using SAGA's saga_cmd. Basicaly I have a lot of grids and shapes (mainly generated in SAGA by vectorization of raster classifiaction results). Now I'm trying to make ...
3
votes
1answer
133 views

How to convert LAS file to ASCII for DSM in SAGA GIS? [duplicate]

I want to count trees in SAGA GIS and when I try to follow the steps in dominoc925.blogspot.com, there was no problem with asci file (i have converted las file (dem)) but there was a problem with dsm ...
2
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0answers
24 views

Can't run SAGA or GRASS commands from QGIS processing toolbox [duplicate]

I can't run anything from this toolbox. I tried running SAGA dissolve polygons and got the following error : Oooops! The following output layers could not be open Dissolved Polygons: ...
2
votes
2answers
1k views

QGIS 2.0.1 Dufour on Windows 8 64-bit: Processing toolbox always produces error saying output layers could not be opened

I have tried to use the Processing Toolbox in QGIS 2.0.1 a couple of times now (using SAGA and OTB) and in both cases the processing tools always return an error along these lines: "Problem loading ...
3
votes
1answer
189 views

SAGA raster calculator, ifelse command syntax problem?

I am trying to get the saga raster calculator in QGIS to spit out all values of a raster that are inferior to 10, and make all other values zero. I think the syntax is correct but I keep getting the ...
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1answer
59 views

Problem with batch mode Saga Raster Calculator

I have to do a couple of raster multiplications for which the batch mode would save me a lot of time. But the only thing I get are rasters that contain nothing but nan values. If I multiply the ...
3
votes
1answer
114 views

Is it possible to highlight water steam sources on Landsat 7 image?

I am trying whether it is possible to view hot steam sources like power plant cooling towers and resulting cloud using satellite images. I was advised to try Landsat (needed free data for initial ...
6
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2answers
3k views

How to install SAGA 2.1 with QGIS dufour on Windows?

I need that someone tell me how i can install saga in qgis 2.0 correctly in windows, because if I install QGIS 2.0 and when I try to use SAGA I get this Missing dependency.This algorithm cannot be ...
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0answers
22 views

Exporting landcover clasiffication from ENVI to SAGA

I have basic knowledge in remote sensing and GIS. I have generated landcover map in ENVI 4.7. How can I transfer or Export/Import this into SAGA so that I perform other functions in SAGA. I want to ...
1
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1answer
121 views

What is the best way to display point data (with standard deviation) using QGIS/SAGA/Manifold? [closed]

I would like to display point data values (indicating biomass at a point) but also to show the standard deviation value for each point. What would be the best method to do this in QGIS (I'm a basic ...
2
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2answers
112 views

What is the source of horizontal and vertical striping in USGS DEMs?

When processing 30m and 10m DEM data downloaded through the National Map Viewer from the National Elevation Dataset, we noticed horizontal and vertical striping not only in the produced results, but ...
5
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1answer
2k views

Installing SAGA GIS 2.1

I am using QGIS 1.9 master with Ubuntu 13.04. I tried to use the SAGA hydrology tools in sextante today and it said they did not appeared to be installed. I checked and sure enough SAGA was indeed ...
3
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2answers
585 views

How do you read GeoTiff-file in SAGA GIS Program?

I'm very new with all GIS-stuff and I got advice that SAGA GIS would be a good program to start with. I would like to read a GeoTiff-file in SAGA, but I can't find an "import file"-function x) Any ...
0
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1answer
923 views

Topographic Wetness Index

Is there any option to SAGA to calculate the Topographic Wetness Index ? I have a big area and I tried many times with SAGA, the last time I thought the results was ok (before SAGA would crash or give ...