Spatial Interpolation Techniques in QGIS

In this tutorial, you will learn how to make use of a discrete point dataset to generate a seamless continuous raster using a number of different geostatistical interpolation methods.
Geostatistical interpolation methods are a set of powerful techniques used in Geographic Information Systems (GIS) and spatial analysis, including within the QGIS environment, to estimate and predict values at unsampled locations based on observed data. These methods are particularly valuable when dealing with spatially distributed data and can be applied to various applications. Popular geostatistical interpolation methods include Kriging, Inverse Distance Weighting (IDW), and Spline.
In the first part of this tutorial, we will see how to make use of Voronoi Polygons (which is also known as Thiessen polygons) to define an area of influence based on the proximity of each point to one another, and create a rainfall distribution map based on a point dataset. We will make use of a color ramp in order to visualise the polygons which shows the gradient of the variable with a clear distinction of the high and low values.
Following that, we will use a very commonly used geostatistical interpolation method called IDW, which stands for Inverse Distance Weighting in order to generate a seamless continuous raster, by predicting values for unknown areas based on the available point values in the same dataset.
Finally, we will also make use of another interpolation method which is called Thin Plate Spline (which you can find under SAGA tools in QGIS) to perform a similar task, and then we will compare the results and see how each interpolation method differ from one another, with some thoughts on how to select a specific interpolation method for a given task at hand.
Download the average annual rainfall sample dataset - drive.google.com/drive/folder...

[@gumedelondukuthulaelishama6777]

A tutorial done with such prowess. I am in awe.

[@aleksandrkasimov2195]

Amazing, thank you!!

[@MohammadHSahil]

Thank you for the great explanation!

[@lbuga3302]

Super! Thank you!

[@prajwalparmar4486]

Very well articulated 👍🏻

[@secretnetizen]

Thanks and alot for an excellent tutorial and also extra thanks for providing file for practice.,🙏🙏🙏🙏🙏

[@space-time-somdeep]

Beautiful lecture

[@chiare6127]

(You’re an angel!) Thank you, super

[@zenobiakusi-afrakoma9781]

You are the best

[@abhinandok190]

Thanks a lot 😊

[@crtnnn]

Perfect, definetely going to show this to my students!

[@geodeltalabs]

Great! :)

[@rabisroy]

Tum bohot accha Kam krta h bhai.

[@LaoShareKnowledge]

good work

[@hasifahkasujja7397]

Been getting these Indian tutorials that lack depth, but this has made appreciate the interpolation technique in GIS. Thanks

[@yashitandon7863]

very well explained.. Can you help me, I have a query. What feature or tool can I use in ArcGIS to show the Metro line expansion over the years and built-up area expansion along it(say, 3km proximity)

[@wombabkalowa4106]

Thanks,

[@zeeoperon]

Thank you, how to show this interpolation on a world/country base map please explain.

[@DanielVargas-yx7ux]

Not sure why It doesnt let me do the IDW with the british grid..

[@valentinaoziegbe3105]

Hi, I'm trying to do interpolation of solar radiation across a country. Which method would you recommend I use?

[@tanviashok8880]

Do such results occur even in small-scale areas, like within 20k sqm?>

[@ellamotherway652]

This is great! Are these points georeferenced?

[@soumyadipbiswas3075]

A full demonstration for vic model would have been great....

[@geodeltalabs]

Hi, i'm not really familiar with it. What's it used for?

[@mohamedalihassan7895]

As students for your vedios i would like to contact you sometimes need for your help. Where would i contact you?

[@sukkiisukant]

why didn't you show kriging?

[@abdullahmaroof84]

can i have this dataset?? for practice reason..

[@geodeltalabs]

Hi sure, please check back in a couple of hours, I will make sure that its uploaded. You will find the link to download the data in the description of the video.