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Questions tagged [modelling]

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

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1answer
39 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 counties (census tract). I have run a Bayesian Spatial Modeling - Conditional Autorregressive model (CAR) Poisson (BYM ...
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0answers
39 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 ...
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0answers
16 views

Polynomial Models for Variogram

I have a set of semivariograms that are not well described by the standard models (and I've tried many of them) due to a dip halfway in the data. To me, to properly model the variogram I would need a ...
2
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1answer
77 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 ...
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0answers
10 views

Incorrect work of cdo -remap command

CDO (link to docs) is operating on Linux. We have latlong ECMWF model forecast and WRF lambert forecast file. When we try to remap ECMWF to the lambert projection we get completely incorrect results: ...
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0answers
68 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 ...
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0answers
22 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,...
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2answers
161 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 ...
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0answers
148 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 opensource software ...
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1answer
131 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
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1answer
109 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 ...
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0answers
193 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 ...
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2answers
776 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?
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2answers
145 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?
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0answers
226 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 ...
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0answers
86 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 ...
3
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1answer
403 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 ...
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1answer
215 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 ...
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0answers
30 views

Interpolation of survey travel data for transport modelling

I am looking for a way to interpolate survey travel data (in VKT) for transport modelling. I have the dataset of VISTA residential transport survey at meshblock level, but I need to get VKT (Vehicle ...
1
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1answer
95 views

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

The user manual for FEFlow (v7.0) states "In transport models, the elemental distribution Péclet Number is available which can be used to check whether the spatial discretization is ...
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0answers
170 views

Retail Huff Model & Network Analyst - Street/Travel Time Network error/issue/question

I am writing in regards to the Huff Model that Drew Flater posted on ESRI's website since I seem to be running into a problem whenever I try to run it with a network. I've tried emailing/contacting ...
0
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1answer
86 views

Temperature and Moisture indices in Geomorphometry and Gradient metrices toolbox

I have generated various temperature and moisture indices using toolbox in arcgis. But HLI output is showing values more than 1. values should be between 0 and 1. similarly IMI values should be ...
1
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1answer
159 views

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

I am using R and trying to fit a variogram model that I created: mod <- vgm(psill = var(newdfNoNAs$yield_cleaned),range= NA, model = 'Sph',nugget = 0) And I used fit_reml <- fit.variogram....
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1answer
77 views

Airborne Smell Modelling

I am wondering if anyone can point me to a resource that will provide a way to model out smells of a garbage dump based on wind? I have been searching through articles on down wind pollution models ...
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0answers
212 views

Database modeling for big data (big set of points X big sets of possible values for each points)?

I'm building a PostgreSQL database with the intent to host modelisation results for different projects. Each project has a set of receptors points (~5000-10000 receptors) and have many results sets (...
2
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1answer
70 views

Spatial resolution for Bioclim datasets

I am new in using Bioclim datasets. I want to model future spread of Prosopis juliflora using landsat 30m. I want to add other datasets like temperature, ppt, elevation, soil moisture, pH, etc. Any ...
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0answers
221 views

ArcGIS 10.2 Model builder Spatial Join user input

I have a model that runs a spatial join and then adds and calculates fields to that joined table output. The model is designed so that a user can change the target features and join features. I have ...
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2answers
784 views

ArcGIS 10.2 Model Builder, getting results to 'add to display' when running as a model tool?

I have a finished model that has been saved as a model tool in a custom toolbox. I add the toolbox to ArcToolbox, double click, set the parameters, and run just like any other tool. I have the model ...
2
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1answer
930 views

What methodology is used to quantify global warming?

This article in the LA Times says: The first detailed global temperature measurements were recorded in 1880. Since then, nine of the 10 warmest years on record have occurred since 2002, according ...
3
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3answers
1k views

Flow Accumulation Python or MATLAB Script

does anyone have any resources for scripting the D8 flow accumulation in Python or MATLAB after obtaining the flow direction values and filling in 'sinks' and 'flats'? I am trying to understand the ...
3
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1answer
69 views

Identifying the best OLS regression model

I have 10 independent variables to include in an OLS regression model. I know how to interpret the results and that for comparing models, the AICc value can be used, where a smaller value indicates a ...
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1answer
13k views

Difference between dynamic model and static model [closed]

I have been going through types of models in Spatial Modelling. As far as I know, Dynamic modeling is done on temporal data while static modeling is time independent i.e. it works on single data set....
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2answers
270 views

How to make input data in MaxEnt with several occurences at the same coordinates?

I have insect traps data with several hundreds insects caught every day. In this paper, authors say "Running the model using the number of mosquitoes per trap-night resulted in clustering of high ...
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0answers
80 views

Modelling zero-inflated spatially autocorrelated data with extreme values [closed]

I have spatially explicit data (above; Longitude, Latitude) with measurements on a random variable (z). This data was not collected in a random or systematic fashion, but instead was recorded ...
0
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1answer
406 views

Modelling soil texture using ArcGIS for Desktop?

I am doing a project for automated soil mapping using landsat TM imagery, I have 3 output rasters: one for sand percentage one for silt percentage and a third for clay percentage. How can I ...
0
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1answer
98 views

joining non-spatial pollution model (csv file) to Qgis

I have csv file with concentration data but without coordinates. Start of pollution concentration connect with that one point on map. Is there any chance ? Start of pollution concentration ...
2
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2answers
164 views

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

I would like to be able to delineate an approximate area of a potential tailings dam breach for an emergency response plan purposes. The tailins dam and pond have not yet been built. The data I have:...
1
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1answer
388 views

Choosing R package for discrete choice model?

I am at a loss as to which R package and approach to use for my modeling. The background is: I have a transportation survey dataset combined with many other GIS datasets. I am attempting to ...
0
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1answer
130 views

Implementing GLMMs in ArcGIS

I am looking to create a predictive model in ArcGIS. I have done this previously with glm with poisson distribution and found it relatively straightforward in raster calculator e.g. exp(intercept + (...
1
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2answers
284 views

Building DEM of large areas

I am putting together a compilation of 1/3 arc second, and 1/9 arc second DEM data for essentially all of southeastern Oregon in ArcGIS. This surface would be used for geomorphological and geological ...
3
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0answers
202 views

3D interpolating

Our final year project domain is soil contamination modeling. We collected soil samples at the depths of 0.3 cm ,0.5cm , 1cm , 1.5 cm in about 25 locations. We considered 8 contaminants- p h, sodium, ...
5
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3answers
583 views

How to run a GAM model in GIS?

How do you generate a species distribution probability map from GAM models? Or in other words, how do you set up a GAM equation in GIS to produce probability of species distribution? It is simple to ...
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0answers
82 views

Data occurrence in openModeller?

I am having problems adding occurrence data to openModeller and I think that the format might be the problem. I am using Excel with the fields: #ID Taxon Name Longitude Latitude. I saved the result ...
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0answers
87 views

Creating model that simulates water flowing down crack, then splitting at 'Y' joint?

Maybe this is a simple problem, but I've been given a task of simulating how water flows in one line, along a crack, and then hits a 'Y' junction, where half the water flows in each of the split ...
4
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0answers
737 views

Preparing Huff model with data to use in QGIS? [closed]

I'm trying to find out about the notion of potential of acessibility using the methods of Huff. I´m using QGIS, with point data (with the variables that I would like to use) and polygons for Europe ...
4
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2answers
6k views

Variogram model fit compatability among geoR, gstat, and nlme packages in R

I'm trying to specify the covariance structure parameters in a linear mixed model (using the correlation structure facilities in nlme). The parameters are estimated from a gstat or geoR variogram ...
2
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1answer
543 views

rasters as independent variables in logistic regression: must they have the same values classification?

I am planning to build a predictive model for land productivity using arcGIS 10.1. and logistic regression. In my model, the Independent Variables would be, among others, distance from rivers, ...
2
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2answers
4k views

How to resample a raster to higher resolution in QGIS?

I'm fitting a SDM using R. A requirement is that all environmental predictor layers have the same extent, origin and resolution. I have high resolution bathymetry data (25m) that I will resample to ...
2
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1answer
1k views

Is there a SWAT model integration for QGIS?

I am trying to use SWAT (Soil and Water Assessment Tool) for watershed management activities. It is a set of commandline tools and needs a complex set of input data some of which can be generated from ...
2
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1answer
81 views

Modeling data in PostGIS when Several Join queries with Geometry are Needed

Suppose you have a database where you have several tables with geometric information and you have several cases in your system where you need to query the tables with a lot of joins (ie: LEFT JOIN ...