Questions tagged [modelling]

A methodology or set of analytical procedures used to derive information about spatial relationships between geographic phenomena.

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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 ...
Bernard Stokes's user avatar
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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 ...
Yosri Sem's user avatar
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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 ...
RashmiSRana's user avatar
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 ...
megsruppUNBC's user avatar
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 ...
nittyjee's user avatar
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1 vote
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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 ...
Tallosx66's user avatar
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 ...
Annegret's user avatar
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 ...
foliveira2's user avatar
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 ...
HarshUp's user avatar
  • 11
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-...
Beeman's user avatar
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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 ...
Dolby's user avatar
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1 vote
0 answers
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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 ...
Wombura Kimacha's user avatar
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 ...
Rayk Henning's user avatar
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 ...
Jabulani Nyengere's user avatar
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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 ...
TreeGIS's user avatar
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1 vote
0 answers
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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, ...
LeslieKish's user avatar
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/...
PGerrits's user avatar
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1 vote
0 answers
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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 ...
user2300's user avatar
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 ...
Babel's user avatar
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1 vote
0 answers
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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 ...
Isaac Newton's user avatar
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) ...
Klaus_Asbjorn's user avatar
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.
Adrian Alonso-Frontela's user avatar
0 votes
0 answers
67 views

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 &...
bita's user avatar
  • 1
-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 ...
coder_001's user avatar
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__(...
Nikolay Yasinskiy's user avatar
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:...
psammodromus's user avatar
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 ...
Mateus Amorim's user avatar
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 ...
Balaji Krishna's user avatar
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 ...
João Vieira's user avatar
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 ...
adamdsmith's user avatar
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 ...
Orca's user avatar
  • 31
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?
Endi Soares's user avatar
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, ...
Tom's user avatar
  • 13
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 ...
jbrengel's user avatar
  • 235
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 ...
Patricia Matsumoto's user avatar
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 ...
R Kumar's user avatar
  • 211
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 ...
francesco lc's user avatar
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 ...
obchardon's user avatar
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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,...
Shahidul Islam's user avatar
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 ...
Konstantin_o's user avatar
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 ...
Aaqib Khan's user avatar
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 ...
DotPi's user avatar
  • 779
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 ...
Rex's user avatar
  • 1,198
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 ...
ApoG's user avatar
  • 61
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?
Art's user avatar
  • 41
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?
traggatmot's user avatar
  • 2,050
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 ...
parallax's user avatar
  • 1,482
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 ...
Kevin's user avatar
  • 347
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 ...
Liza's user avatar
  • 287
-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 ...
Shishir Rao's user avatar