Questions tagged [modelling]
A methodology or set of analytical procedures used to derive information about spatial relationships between geographic phenomena.
128
questions
2
votes
1
answer
58
views
Representing polygon features using arrows that represent direction of orientation?
I have a polygon layer that stores results obtained from simulations run on a hydrological modelling software, ICM.
A particular table within the attribute table of this polygon layer has details ...
0
votes
0
answers
118
views
Creating a centerline of polygon by using QGIS built-in algorithims algorithms
In the last few weeks, I have discovered different ways to retrieve the center line of a polygon in QGIS. I am working on an urban Digital Twin. On this project I am focussing on adding more detail ...
0
votes
0
answers
147
views
How to interpret values of elevation standard deviation statistic (and not elevation mean) from DEM
I am trying to interpret the standard deviation of elevation to understand the topographic landform of my study area.
We have 2km*2km grids in the study area for which we extracted certain landscape ...
0
votes
1
answer
62
views
vis.gam spatial interaction output as a raster grid instead of plot object
I am trying to create an object that can be put into tmap or another GIS platform from my model output. I created a model using the gamm4 package that has a spatial interaction term. See an example ...
1
vote
0
answers
33
views
How to model the fastest gain of contiguous area above a certain value? [closed]
Imagine you have a grid of squares with values 1 to 10.
Some squares are "available", and some are "unavailable", and must be "gained".
Each step you can only gain ...
1
vote
0
answers
322
views
Blender GIS convert 3d model to Mesh
The GIS model that shows in Layout (Export_Google_Sat_WM).
Can it be Sculpted?
I can't seem to see it in any other viewport like modeling, or sculpting. It can only be viewed in Layout. I have watched ...
0
votes
1
answer
118
views
R dismo threshold() returns negative values
I model tree species in R using various models (glm, gam, brt). For evaluating their prediction I run following code after my model calibration.
#threshold version 1
##calculating ideal cut-off value ...
2
votes
0
answers
85
views
Is there a "gradual style" available in QGIS to do something like this? [closed]
I need to print my map with something like this. I tested several styles in QGIS to represent this idea, but the closest I got was using the shapeburst fill.
The idea is:
The colors represent ...
1
vote
0
answers
54
views
HEC-GeoHMS Outlet Point Connectivity
The "Check Data" option in HMS tab of HEC-GeoHMS is showing a problem in the VIP relevance points which is as follows:
Checking project points [VIP points]... Checking VIP Point: Outlet1
...
0
votes
1
answer
28
views
Interpolated DEM RMSE
I'm trying to figure out the 'true' error associated with interpolated cells in a DEM, which itself is known to have a RMSE of 0.15m.
DEM has RMSE of 0.15
Interpolation model shown by cross-...
0
votes
2
answers
157
views
R: Automatic selection of covariates in GWR
I am performing geographically weighted regression (GWR) and I have 4 covariates and 1 dependent variable. I want to find the best combination of covariates that yields the lowest AIC score. But ...
1
vote
0
answers
159
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Receiver points appear as circle around building footprints in Openoise plugin for QGIS
I have been trying to get receiver points using Openoise plugin for QGIS 3.18 Zurich but they appear in a circle form around the actual building footprints.This is a Noise Modelling tool that helps to ...
3
votes
1
answer
595
views
Conditional branch algorithm in QGIS modeler link to a certain layer and certain columm
I´ve got a modeler, which has limitation for the input.
I want to build a conditional branch which stops the algorithm when the limit is overstepped.
"example" - colum with numbers from ...
0
votes
1
answer
344
views
Interpreting semivariogram from ArcGIS Pro
Am having an output for semivariogram from ArcGIS Pro as per below. However, the distance looks small.
Is there a way to adjust the distance?
Not only that, how best can I interpret the x and y values ...
0
votes
0
answers
30
views
Plotting polyline trail using slope raster with least change in slope and ArcMap [duplicate]
How do I plot a trail in ArcMap so that it runs from point A to point B?
This is part of a larger model I am working on that takes various variables into account and creates a cost layer that I then ...
1
vote
0
answers
24
views
Choosing geospatial statistical test using building characteristics and distance together
New to geospatial analyses and I am trying to assign a building footprint to be a type of building (e.g., industrial building).
In another dataset, we have determined the average building area, ...
1
vote
1
answer
504
views
How to calculate the shortest path of adjacent points, from an origin to destination points? (ArcGIS Pro/ArcMap)
For a project I am trying calculate the shortest path (marked by points, not lines) connecting a point of origin to a destination point (different feature layer) and automate this for several segments/...
1
vote
0
answers
243
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How to compare the results of the random forest algorithm with the other SDMs?
I'm using the random forests algorithm in species distribution context. I have presence-absence as a dependent variable, so I decided to work with classification. At this point, I recovered the ...
8
votes
1
answer
417
views
Opening old QGIS model in current QGIS versions
There is an older answer by @underdark to this post: Finding centrelines from polygons in QGIS?
She links a QGIS model that apparently was created in QGIS 2.12. It has the file extension .model
When I ...
1
vote
0
answers
32
views
What Explained Variance is good to proceed with Predictive Soil Mapping?
I have 1851 soil samples data on pH covering a study area of 7482sq.km in northern Ghana and I am using 52 environmental long-term average variables (Relief, Climate, MODIS Reflectances and derived ...
1
vote
0
answers
59
views
QGIS - graphically depict movement patterns
I want to make a graphical depiction in QGIS of two different datasets showing pedestrian movement patterns in a city center. One data set is observed, and the other is projected.
My data (CSV) ...
2
votes
3
answers
1k
views
Extract by expression - N first
How can I "extract by expression" the N first (10 highest values of one column, for example)
I need it for the graphical modeler.
0
votes
0
answers
67
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Obtaining weight of evidence plugin for ArcMap
I read this article:
An integrated user-friendly ArcMAP tool for bivariate statistical modelling in geoscience applications
but I did not find this tool "bivariate statistical modelling , BSM &...
-1
votes
1
answer
1k
views
How to process environmental data for the input in MaxEnt (or any other modelling platform)
I have downloaded some environmental rasters from Worldclim. Now, I want to generate an environmental layer for MaxEnt by applying conditions on those rasters. These rasters are 32 bit, floating point ...
1
vote
1
answer
43
views
Stack of time-spatial maps is not read by readmap method
I am new in PCRaster, so I made a primitive model to test the functionality. I need to read input from precipitation data maps for each day. My code is:
class Model(DynamicModel):
def __init__(...
1
vote
1
answer
717
views
Calculating Euclidean distance in ArcGIS
I am willing to model the distribution of an amphibian species in relation to climate and land cover in MaxEnt. For this I have downloaded the WorldClim data and the Global Consensus Land Cover (https:...
1
vote
0
answers
195
views
AERSURFACE - How to calculate the inverse distance weighted geometric mean of surface caracteristics
I need to calculate the inverse distance weighted geometric mean of the cell values of different sectors within the 1-km radius from a weather station, using QGIS. I'll try to make it clearly below ...
0
votes
1
answer
2k
views
Error: could not find the function crs [closed]
library(sp)
coordinates(acg) <- ~lon+lat
Error in coordinates<-(*tmp*, value = ~lon + lat) : setting
coordinates cannot be done on Spatial objects, where they have already
been set
...
0
votes
0
answers
73
views
Consequences of projecting in different resolution rasters
I have used 2.5 resolution enviromental rasters to build a model using ENMeval. Which are the consequences of projecting (ENMeval::maxnet.predictRaster function) a choosen model in the same area in a ...
1
vote
0
answers
34
views
Model binary rasters over time against non-spatial variable (e.g., inundation over time vs. gage height)
I have a time series of raster images for a study area that have been processed to a binary classification (inundated/not inundated). Each image in the series is time-stamped and can be associated ...
0
votes
2
answers
3k
views
Parameters of the Muskingum-Cunge Model in HEC-HMS
I'm trying to simulate the flow of a river in HEC-HMS and for the routing model, I have chosen to use Muskingum-Cunge. In preparing the model, I used HEC-GeoHMS.
When I got to check the parameters ...
1
vote
2
answers
1k
views
How to delete multiple columns in the QGIS processing model?
I made the union of two tables I want to erase some columns. How can I do this automatically?
1
vote
1
answer
48
views
How to create multi-scale variables from landcover data
I have calculated raster files with values of 0 and 1 for each landcover attribute I am interested in. I would like to make multiple raster files containing different cell sizes. e.g 100m2, 500m2, ...
2
votes
1
answer
182
views
Why difference in delineation of watershed by two online watershed modeling tools?
I am using two online watershed delineation tools- eRAMs and Model My Watershed (MMW)- to auto delineate watersheds using water quality monitoring sondes as my outlet points. I have three pieces of ...
1
vote
2
answers
415
views
Plotting/Exporting the Spatial Random Effects in BYM model - CARBayes - in R
I am working with visceral leishmaniasis disease cases in a small city with 100 polygons (census tract).
I have run a Bayesian Spatial Modeling - Conditional Autoregressive model (CAR) Poisson (BYM ...
1
vote
0
answers
362
views
Automatic Roof Modelling on QGIS
I have an area that I am modelling using QGIS, I have each building outline, and I extrude it via qgis2threejs. I wish to add another level of detail and model the roof of each house, which doesn't ...
3
votes
1
answer
190
views
Why TauDEM specialized tools (e.g. D-Infinity Distance Down) are only available with D-Infinity flow model?
I would like to know why most TauDEM specialized tools have been developed just for the D-Infinity flow model.
Is it because the D8 would not make sense for these algorithms, or they just have not ...
6
votes
0
answers
91
views
Avoiding border effect in traffic modeling?
I'm creating a traffic model (using the Four-Step Travel Demand procedure).
I have a road network (grey lines and grey node) and traffic injector/attractor (orange lines and orange nodes) as it can ...
1
vote
0
answers
49
views
Can I determine hydraulic load on river bank with hec-ras? [closed]
I want to calculate the force exerted by wave action on river bank.
If I know the discharge, flow rate and water level, can I calculate the hydraulic load acting on river bank with hec-ras?
If not,...
1
vote
2
answers
663
views
Testing species distribution model residuals for spatial autocorrelation?
I build a species distribution model with data from location A and tested it on location B. The picture shows a rastermap of location B and what I guess should be the model residuals.
Green - are ...
1
vote
0
answers
493
views
Modelling fiber optic network using free solution in GIS? [closed]
I am a beginner to GIS software and currently I have been given a task to model a telecom network. Most of the solutions that I came across are proprietary.
I want to know which open source software ...
0
votes
1
answer
385
views
GWR with dependent and explanatory variables in different files
I have a point shapefile (let's say A) with pollution measures (let's say Y). My hypothesis is that pollution at theses locations is primarily driven by nearby industrial units and not by activities ...
0
votes
1
answer
593
views
Getting Negative values in Regression based Biomass model!
I am using Multi Linear Regression (stepwise method) to estimate above ground biomass. Different spectral indices and other variables mostly derived from Landsat 8 OLI are used to check potential ...
1
vote
0
answers
966
views
GRASS r.sun (in QGIS) computes higher radiation in winter
I am using a 1m DEM layer (Poland CS92, ETRS:2180). From this DEM I've computed Aspect and Slope in QGIS through grass plugins. I did a test run for 15th day of the year and 165th day of the year. The ...
2
votes
2
answers
10k
views
How geotiff converted to 3d model? [closed]
I have image .tiff (format geotiff). How I can convert the image to 3d model (terrain)? Blender or world machine can do it?
1
vote
2
answers
246
views
Open Source GIS tools for using LiDAR to estimate storage behind dams/culvert [closed]
Can you recommend an open source GIS tools for modeling the water impounded on the upstream side of a dam using LiDAR data?
2
votes
0
answers
792
views
Removing spatial autocorrelation (SAC) using Moran's Eigenvectors and predict distribution?
I successfully managed to incorporate moran's eigenvectors as predictor to my species distribution model using GLM (logit). I followed Dormann et al. (2007) and the appendix. I think I got corrected ...
1
vote
0
answers
213
views
Generalize raster data dependent on DEM?
I'm working on a generalization process of probabilistic calculated raster data (rockfall extend, data shows probability of being hit by a rock in %; I used binary data, 1 for "one hit or more", 0 for ...
4
votes
2
answers
2k
views
How to create a sound map using ArcGIS?
I have locations of the points which produce sound. I want to create a sound map based of those points, topography, and the distance at which a sound can travel. On this picture you can see the red ...
-1
votes
1
answer
460
views
Cumulative delay function for rainfall-runoff modeling using TOPMODEL [closed]
I am trying to model rainfall-runoff using TOPMODEL in R. The TOPMODEL needs an input called "cumulative delay function". The R documentation says "Flow is routed through a delay function which ...