hello to all welcome to the channel geog Guru in this video we are going to learn about how we can perform the multiple criteria overlay analysis in qgis so in order to perform this exercise we will try to identify the areas to build a new parking facilities that can help in reducing bicycle theft and the criteria for our site selection is that the proposed area must be in a bicycle theft hotspot and it should be within the 50 m of the bicycle route and it should not be within the 50 m from an existing bicycle parking facility and for this exercises we are going to use uh the B bicycle infrastructure data for Westminster borrow London city so let's begin so we have open our uh qgis and already open the data set so we are using three Vector layers one is the Cy cing route and that is the uh cycle parking which is the point data set then the shape file of Po shape file of the westmin borrow area and the roster of cycling theft heat Maps so which uh this information shows The Hot Spot uh where the cycle theft occurring more often so this uh first of all we'll just change the color of all the necessary inputs I and for the heat map I'll just select F so uh now I can see that there are some hotspot area for example these are some hotspot area which is uh uh at particular point which is is a higher number of cycle theft reported so uh first of all the thing that we want to extract this hotspot area where uh the cycle theft is more often into the vector format so first of all we will will go to the processing toolbox and we will search for raster calculator and under the roster analysis there is option roster calculator we'll just open this then there is one cycle theft heat map and we will give a criteria uh so here the values are ranging from 1 to 28 so we are taking for example 12 you can take as much as you want like 15 10 and the reference layer that we want to provide is same as as it is the cycle theft heat map and the output layer we are not saving as a permanent layer we will just save to a temporary file and click run so the resulting roster is nothing but a Boolean map with a value of zero and one one is the value where our criteria meet that means uh cycle ta is more than 12 and the black is the place where the cycle ta is less than 12 so next thing thing that we want to do is to extract this o1 area in a vector format so for that there is a option known as polygonize in the judal tool so if you type polygon and go to the jiga judal there is a function known as polygonize r two Vector so in the input layer we will provide output that means our output Boolean map and click frun so uh I'll just uncheck this both Ras layer so now we have created created one vector layer where if you just open the attribute table we have two type of values one and zero one is our targeted hotspot location so we want to extract only the vector uh polygon which has the value one so for that there is an option known as extract by attribute so in the vector selection there is an option extract by attribute and we will select vectorized and the attribute is DN which is equal to 1 and click run I'll just close this and I'll just remove all the unnecessary output so now uh I if I just uncheck this route and cycle so these are the hot spot area where the uh cycle theft is more than uh 12 as per the heat map so these are the desired location for the proposed location next thing that we want to do is uh want to create the buffer of this cycle route that uh one of the criteria is that it should be 50 m within the cycle route so we will create a buffer around this line and it should not be uh within the 50 m of already parking uh spots so we will also create a buffer around these parking spots so what we will do uh we will search for buffer so under the vector geometry there's an option buffer so first of all we will provide for cycling routes and we will give the distance 50 please make sure that it should be in meters okay and I'll just click run so a buffer L has been added I will again go to the parameter and this time going to select the cycle parking and this time also the buffer is 50 m because it is uh our own criteria you can select 100 or as per your desired output I'll just click run so now we can see that we we have two buffer layer uh one is this uh parking spot so I'll just change the name you can change the name by pressing F2 so this is the parking buffer and next buffer layer is the route buffer so I'll just press f2 route buffer you can also change the name by right click over this and click on the properties and change the ray name uh so these are are all the temporary layers I will not save them permanently uh I'm going to save the permanent layer which is the final layer so next thing that we want to do is uh go to the intersection command and under the vector overlay there is a command intersection and in the intersection we are uh going to provide two things uh uh one is the Hotpot that means extracted one and next is the uh route buffer I'll just click run so I'll just uncheck only the output thing and let's see what the output denotes so these are the output uh which is a common intersection point of the Hotpot area where the value is more than 12 as well as the route buffer so where uh all these two layer are intersecting so this particular vector layer is the result of that two particular intersection now uh we want to so these are um our uh the area for the propos site now we want to eliminate the area which is come which are coming 15 M within the already parking zone so these are already parking uh points are there and this is the buffer of the parking so we can see that some portion of this particular polygon has to be eliminated and for that we are going to use the difference so there is a command known as difference in the vector overlay and in the input layer we are going to provide the intersection and the overlay L we going to provide parking buffer and click run and we are going to uncheck all of this so uh these are the few polygons which are the which is our final result that means uh most appropriate uh proposed spot for the uh cycle parking which is uh as per our criteria so that's it for the day hope you uh like this video if so and if you found this video informative then please hit the like button uh share this video And subscribe to the channel thank you