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11 votes
Accepted

Opening old QGIS model in current QGIS versions

Processing in QGIS 3 was refactored a lot and many algorithms were changed. So it is not possible to covert old models into new format. You need to recreate it. says Alexander Bruy, QGIS contributor, ...
Kadir Şahbaz's user avatar
6 votes
Accepted

Why TauDEM specialized tools (e.g. D-Infinity Distance Down) are only available with D-Infinity flow model?

Mostly this is a matter of implementation. They have not been implemented. Typically, each tool was historically developed in for a specific project or purpose and this development process has not ...
David Tarboton's user avatar
5 votes
Accepted

Testing species distribution model residuals for spatial autocorrelation?

Given an inevitable nonparametric model structure, a residual in the traditional sense is not possible. You could approximate the response, Pearson's or deviance (likelihood ratio chi-squared) ...
Jeffrey Evans's user avatar
4 votes

How to create a sound map using ArcGIS?

Well, I don't know if there are any standard out of the box ArcGIS tools set up for sound modelling, and I know sound-waves do have different properties than light waves that may affect your modelling ...
John's user avatar
  • 3,863
4 votes
Accepted

How to calculate the impact and extent of damage of a potential tailings dam breach with ArcGIS?

There are quite a number of steps and additional data that you'd require before you can answer this question with a level of detail that is appropriate for such an important question. This is not just ...
Phophos's user avatar
  • 56
4 votes

3D subsurface modelling

Geomodelr might be what you are looking for. Geomodelr allows you to create cross sections from boreholes, or use geophysical data in the form of images. For geophysicists it's particularly cool ...
Ricardo Serrano's user avatar
4 votes
Accepted

Getting Negative values in Regression based Biomass model!

The crux is most likely in the fact that you are using a MLR, as this method can indeed result in values below 0, while a negative biomass obviously does not exist in real life. As for the ...
LMB's user avatar
  • 1,166
4 votes

Error: could not find the function crs

First message error: setting coordinates cannot be done on Spatial objects, where they have already been set You can't set coordinates again if they are already set. Second message error: ...
aldo_tapia's user avatar
  • 13.7k
3 votes
Accepted

How to calculate the shortest path of adjacent points, from an origin to destination points? (ArcGIS Pro/ArcMap)

The correct way to perform shortest path is to use Travelling Salesman algorithm, ( as per FelixIP comment) - which has been implemented in ArcGIS in the Network Analyst extension. https://desktop....
nr_aus's user avatar
  • 3,566
3 votes

Spatial resolution for Bioclim datasets

The finest resolution of Bioclim is 30 arc-seconds, which translates to approximately 1 kilometer (1000m). You can certainly resample the data to 30 meters but this would be quite invalid because ...
Jeffrey Evans's user avatar
3 votes
Accepted

Open Source GIS tools for using LiDAR to estimate storage behind dams/culvert

You could also consider using GRASS-GIS to import and process your LiDAR data. There is detailed information provided on the GRASS Wiki and an example of a DEM created and visualised included below. ...
dmci's user avatar
  • 4,892
2 votes

Open Source GIS tools for using LiDAR to estimate storage behind dams/culvert

You have a LiDAR derived surface model and you want to calculate the volume of water that would be behind a theoretical dam? If so, have a look at this link http://www.bc-consult.com/tut/QGIS-volumes....
GBG's user avatar
  • 9,959
2 votes

How geotiff converted to 3d model?

A quick search on the internet, I found that there are many tutorials available to show how to import raster DEM in Blender: How to Download and Import a Real World Terrain in blender (Youtube) ...
ahmadhanb's user avatar
  • 41k
2 votes

How to delete multiple columns in the QGIS processing model?

In QGIS 3, there is the Drop field(s) tool which can be added to your model and allows you to select which fields you want to keep or drop.
Joseph's user avatar
  • 75.9k
2 votes

How to delete multiple columns in the QGIS processing model?

You can use Refactor Fields, as part of your model.
GSienko's user avatar
  • 1,091
2 votes

Extract by expression - N first

Use this expression: array_foreach ( -- iterate over all entries for each value of the series created in the next line generate_series ( 0 , 9 , 1) , -- generates a series from 0 to 9 with ...
Babel's user avatar
  • 71.9k
2 votes

Conditional branch algorithm in QGIS modeler link to a certain layer and certain columm

According to https://github.com/qgis/QGIS/issues/39119#issuecomment-768642727 this is currently not possible as those variables do not update in the scope of the model.
bugmenot123's user avatar
  • 10.9k
1 vote
Accepted

R: Automatic selection of covariates in GWR

You can construct and manipulate formulae as character objects and convert them to formulae. Here's something: covars = names(block.data)[-1] L = unlist(sapply(1:4, function(n)combn(covars, n, ...
Spacedman's user avatar
  • 64.6k
1 vote

Extract by expression - N first

You can try the QGIS processing algorithm Execute SQL (documentation) with : SELECT * FROM input1 ORDER BY YOUR_FIELD desc LIMIT 10 SELECT * : select all data from your layer FROM input1 : according ...
J. Monticolo's user avatar
  • 15.7k
1 vote

Parameters of the Muskingum-Cunge Model in HEC-HMS

In the HEC-HMS 4.3 Users Manual I found the following text: "The index flow should represent the expected maximum flow in the reach". So could you put in some arbitrary flow for the index flow, ...
Mark Boucher's user avatar
1 vote

Parameters of the Muskingum-Cunge Model in HEC-HMS

In hec-geohms you can do parameters>TR55 flow path segments parameters>TR55 flow path parameters parameters>TR55 export to excel Check this info, make any changes, then in excel go to addons there ...
Jake 's user avatar
  • 21
1 vote

Plotting/Exporting the Spatial Random Effects in BYM model - CARBayes - in R

I always forget which of the greek letters in CARBayes refers to what, but can usually work it out from the dimensions of the things returned in the samples. Using the toy example from ?S.CARbym, I ...
Spacedman's user avatar
  • 64.6k
1 vote

Testing species distribution model residuals for spatial autocorrelation?

Yes. You already have point data, it's just presented in the form of a raster matrix, and not the vector-based points that your available Morans I algorithm expects. Morans I works fine on raster data ...
Senshi's user avatar
  • 1,767
1 vote

GWR with dependent and explanatory variables in different files

Geographic Weighted Regression is used to look at how a process may vary across space, shown by the varying regression coefficients. So you can use this to potentially look at how your dependent ...
Liam G's user avatar
  • 2,156
1 vote

How geotiff converted to 3d model?

You can try QGIS 3j's plugin. See: https://plugins.qgis.org/plugins/Qgis2threejs/
LMB's user avatar
  • 1,166
1 vote

Open-source GIS implementation of the Huff model

Definitely take a look at this: https://rpubs.com/MichalisPavlis/huff_model and the R library hufftools, which also shows exactly how to download and use a street network for an entire country. The ...
George D Girton's user avatar
1 vote

Cumulative delay function for rainfall-runoff modeling using TOPMODEL

Found help here https://idea.isnew.info/how-to-calculate-the-longest-flow-path-in-grass-gis.html https://idea.isnew.info/r.topmodel.html Find the longest flow path (LFP) using r.stream.distance ...
Shishir Rao's user avatar
1 vote

Use of the Peclet number in FEFlow as a mesh-quality metric

From the FEFlow forums - (Bjorn Kaiser) The finer the mesh the lower the Péclet number. As a very rough rule of thumb the literature often said that the grid Péclet number should not exceed a value ...
Coastal's user avatar
  • 46
1 vote

Temperature and Moisture indices in Geomorphometry and Gradient metrices toolbox

First, the HLI is derived using slope and aspect so, there is no focal window used in the function, just the standard polynomial used to fit the slope direction and angle. Please, keep in mind that ...
Jeffrey Evans's user avatar
1 vote
Accepted

Fixing error in if (any(model$range < 0)) statement when fitting variogram in R?

From the documentation: fit.variogram.reml package:gstat R Documentation REML Fit Direct Variogram Partial Sills to Data Description: Fit Variogram Sills to Data, using ...
Spacedman's user avatar
  • 64.6k

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