Creating Grids in QGIS # QGIS Tutorial - QGIS Q & A

[Music] [Music] so [Music] hi guys welcome to today's qgis tutorial in this video we will learn how to create grids in qgis you can subscribe to this channel to follow all my previous useful tips and tutorials let's get started so today we are going to learn how to create grids grids are very very useful especially when you want to show coverage and it comes in handy when you want to create an atlas map so let's start today's exercise so today i'm going to load a raster layer showing the our area of interest so to load the raster layer i'm going to go to layer add layer addressed a layer then i'm going to load the eraser layer for a region that we looked at in a previous exercise so i'm going to click on these three dots here and i'm going to go to gis data raster tiles then i'm going to load an area of interest five here it's a raster time for region for my region of interest so i'm going to click on add and then i'm going to click on close once it has been added into qgis so actually this is my region of interest you can see if i zoom in and out i have this very nice image of my region of interest you can see my region of interest as a river that is passing from east to west so what you want to do we are actually interested in this river and you want to create grids for the whole of this region so that we can actually just have grids for only this river and create a that last map that is actually going to show this portion of of my my image so the first thing you do when you want to create this you go to vector under vector you'll scroll down to research tools then you're going to select create grids then it will give you these these pop up here so what grid type do you want to create you have to create uh polygons so we'll select rectangular polygons you can actually select any other that you want to create but i for this scenario you're going to use the rectangular polygons then the grid extent we're actually going to create a green accent for all for the layer that we have just already so i'm going to say i'm going to select the area of interest five you can actually even do it on the canvas if you want or you can use the map converse extent so i'm going to just going to use the area of interest 5 and you see it gives the left and the right coordinates of left bottom and right top coordinates then the horizontal spacing now here which is in meters i am going to say i want greens that are let's say 500 meters horizontally and for the vertical one i'll say maybe 400 meters so that i have griefs that are 500 meters horizontally and 400 meters vertically then i'm going to just leave the rest as it is then the green crs i'm going to use the pseudomecata as my projection then i'm going to now save my new layer i can save it as a geopackage layer or i can just save it as a file i'm going to save it as a file then i'm going to save it in my data folder which is a gif data and going to create a new folder here and i'm going to call the new folder here grids then i'm going to save the grids dimension like maybe say i can call it grid one maybe 500 by 400 so create 500 by 400 because i i think it looked like 1500 so i'm going to collect grid 500 by 400 then i can save it as your package layer or as a share file whichever you like so i'm just going to save it as your package layer click on save then i'm going to click on run and it pretty much takes very very few seconds and you can see it has finished the execution in 141 seconds i'm going to click on close and you can see now there's a grid that is actually covering our area of interest what i can do is i can bring the grid down or i can just sign the grid so that i can now actually be able to see my image so i'm going to style my grid so i'm going to right click on my grid go to properties then symbology i'm going to select instead of a simple field i'm going to select a simple line then i can change even the color of my grids to any color i want increase the thickness a bit click on apply and you can now see our grids which are 500 by 400 meters apart so i can even decide to measure the grids to make sure that they're actually 500 meters by 400 meters so i'm just going to zoom into one region here and select this corner here then i'm going to select the measure tool a measure line then i'm going to change this to meters and then i'm going to just select this corner here and measure it up to here you can see it's 500 meters and if i do the same thing going down it's 400 meters so that is how you can create grids in qgis the other way that you can create grids is just by coming to the your processing toolbox you can access that you're pressing toolbox by just clicking on the processing toolbox here and it will appear here so the next thing you do is you go to vector creation then under vector creation you just select create grids so we're going to do the same thing again here but with different dimensions i'm going to create grids which are rectangular polygons still the extent i'm going to use the same same extent still area of interest five then the horizontal spacing i'm going to say maybe let's say 600 by vertical spacing i'm going to put it equal to the horizontal spell spacing which is 600 so i'm going to just use the same but these are 600 meters by 600 meters then the overlay i'm going to leave everything else the way it is usually including the projection then i'm going to create save to file then i'm going to just change here instead of having 500 by 500 at how maybe say 600 by 600 meters then i'm going to say save it as your package layer click on save then click on run and give it some time to think about what it's doing and just finished running then executing the analysis then when you look at this one now when you go to the measure tool you'll find that now the dimensions are different you can see this is 600 meters by 600 meters here so that is how you create grids now when you look at the attribute table i could just even bring the other grids below this and you can see that i mean the 600 by 600 actually covers a bigger area than the 500 by 500 so it's up to you to decide which kind of dimensions you want to use so we're going to just open the attribute table up there 500 by 500 by 400 meters and look at what it contains and you can see it has the fid and then it has some coordinates for the left top and right bottom of each and every green so what i'm going to do is i'm just going to now label them i'm going to label them using the fid to use the fid then the text is going to be maybe say red text and i'm going to place my pieces at the centroid but i'm going to create a buffer right back around it and click on apply okay and you can see i have 121 grids from our initial degrees of 500 by 400 and if i do the same thing for now the the other grades i'll go to the properties label them using the fid i leave them to black color then i change the symbology to an outline and i give it that black outline which is not a problem i increase a bit and you will see i have 80 grids in my second layer so my first layer has more degrees than the second because of the dimensions and now what you can do now is you can just select the grid within the river and run our and create our very nice atlas map showing the coverage of this area for you to be able to now create that you'll have to select them manually using the select tool so i'm going to use the select tool and i'm just going to select by holding the control key down and selecting the greens that are just din the area coverage of the river all of them all the groups that are covering the river and then i'm going to create a new layer out of them so i'm actually selecting all all the grids that fall within the river and i'm going to create a new layer out of these by right clicking on the layer save selected features as because they're saving only the selected features i'm going to save them as your package layers then i'm going to call them and to save them in my my working fold.gis folder and i'm going to call them in the clips folder and i'm going to call it 6x600 underscore selected then click on save then i'm going to say okay and it will now create only the grids that's actually covering my my river so i can decide to copy the style and just press the style so now i have greens that are covering actually the whole river network of my region of interest that's it for today's exercise if you found this video useful and you want to learn more on qgis subscribe to my channel don't forget to give this video a like otherwise i'm just happy you're here see you in my next video [Music]

Channel: WiseGIS

Views: 818

Keywords: qgis, gis, qgis tutorial, qgis tutorial for beginners, qgis tutorial making a map, qgis 3.10 tutorial, q tip, fishnet, how to create grids in qgis, qgis hannover, how to create fishnet in qgis, open data, raster data, vector data, vector data structure in gis, remote sensing

Id: KCV7rsOzjsw

Length: 13min 0sec (780 seconds)

Published: Tue Jan 12 2021