QGISHydro Webinar 1: Georeferencing and digitizing vectors

we're already with 92 people the thing we're gonna get slowly started some more people will join that's that's okay I'm gonna put up some slides here so welcome to this webinar of course we are in strange times with the coronavirus and I hope you're all okay and healthy and I hope your family is also and I hope you who get through these very tough times that everybody's facing all over the globe and Kurt and me we were thinking about what we could do and you know the open source world tries to get the people together and we thought it would be a nice thing to have a webinar where we just introduce the topics in our book get through it and answer a few of your questions and then have some Gio beers to have a bit of cheer in this time when everybody's or many people are staying at home I'm also working at home now for a week and try to do good things and keep the faith and still guide my students so we'll have these webinars every week for several weeks long and based on the book so I'm going to introduce myself for the people who don't know me so I'm answer on the cost I'm a senior lecturer at ihe Delta Institute for water education in Delft the Netherlands I'm doing this on a personal title these Friday evenings my background is that I'm a physical geographer I did my masters and my PhD at the Utrecht University at the department of physical geography in the Netherlands then I was a researcher at the Flemish Institute for technological research in Belgium Vito and studied lenses change modeling and water quality modeling those topics and there I got really into open source and since 2012 I work at ihe Delphis lecture I'm a board member of the Dutch qgs user group and my main interests are open source GIS obviously and modeling I'm like Kurt qgs certified instructor so all our trainings give the right to have the participants to get the official QJ certificates and we're in that way we also contribute to curious I'm interested in remote sensing for hydrology I do a lot with that at ihe Delft and in my projects I work on data sharing on open data and spatial data infrastructures it also be a part of one of the the chapters that we're going to do during the webinar and yeah they don't think we are super computer nerds we are but fieldwork is also important so we need to always see the link between what we see in the field and go out there measure it with devices and come back to our computers to process the data and do the interpretation you can reach me to my email address or on social media and yeah good to be around with you so here's a quarter give him the mic thanks Hans yeah I'm Kurt Mickey and I'm the co-author and on the book queue just for Hydra hydrological modeling I got my geography degree from the University of New Mexico and that's where I'm based here in Albuquerque New Mexico and I operate my own consulting business bird's-eye-view I'm an osteotome member and it's hard to believe at this point but I've authored six books authored and co-authored six books on QGIS at this point the cutest four hydrological applications is the most recent one and I also published discover q just 3x last year which is a large workbook for anyone wanting to learn a really thorough treatment of all the capabilities in QGIS I'm a qg certified instructor and with Hans I help manage the cutest certification program for the cutest project and I do a whole mix of spatial analysis and cartography and teaching with my business and I've also in the last year helped start a new initiative called the Q cooperative which is myself and a number of other power users and core developers of QGIS located around the world and we're there to provide support services so if people need customs they - cutest new features plugins training things like that we can help so the you can see all the URLs and how to contact me they're great Kurt so we'll have seven webinars this first one is about preparing data from hardcopy Maps I will go into the details in a bit the second one next week so every Friday we will do this is about importing tabular data into pooja's the third one is about spatial analysis with map algebra so mostly the rest are things that you can do in Kiryas then chapter 4 very important for hydrologists and people in water management the stream and catchment delineation and the fifth session is about adding open data to your catchment and I'm thinking of doing maybe something with a mapathon related to that so keep you posted on those ideas the sixth topic is calculating the percentage of men covered for such catchment when we do some vector analysis and the 7-1 court will show you everything about map design to make these nice catchment maps like we also have a cover of our book this book is now on a discount because it's World Water Day this Sunday and I will give you the coupon code at the end it's huge it's hydro and if you order the book through the link on this slide and you can get 30% discount and certainly to have the book next to you is is useful when you follow these webinars okay so for today we are repairing data from hard copy homes please mute your microphone if you're not talking so told me about geo referencing a scanned map and using the geo reference Sergey don't plug in a few other plugins introduced and then after we have done with your referencing checking of course the results and digitizing the factor layers in my geo package so we're not going to use a shapefile in this exercise we're going to use it here we'll follow more or less the steps in the book sometimes we will add more you can also ask your questions in the chat box to Kurt of course the book is more detailed and has all the steps so this is not comparable to of course we will give you at the end some ideas of course as you could follow if you want to learn more about this so I'm gonna switch to I'm gonna first share the map that we're going to do reference so this is just a picture it's a JPEG file and it comes without coordinates so this is just a JPEG that's you can have after after downloading the course data from the book and what you see here you can open the picture in any editing program that you have and you have to always inspect a map before doing anything in GIS so we're gonna inspect if we can find any coordinate information on this map and we find here different coordinate systems we find here something that we can recognize as degrees minutes and seconds here there's a number that is related to this grid we see a grid on the map it says 581 thousand metres east and then 582 but they remove the 0 so it goes here into kilometres then there's here something in minutes and degrees or in inches and feet not so clear so this is a real map here we see feet so let's see what the map says about this projection it's a bit a complicated one because you have to read a few things and if we read this we see here that the projection and thousand meter grid is zone 18 of universal transverse Mercator so that means UTM zone 18 and it's United States of America so that is northern hemisphere so we already know that is UTM north's zone 18 and we are going to use this grid to georeference because this grid gives us the notes where we can read the coordinates from the sides so if we can select those nodes in the software and indicate the coordinates that belong to those nodes then we can geo-reference the map so there's some other information here there was at that time a translation to another datum but the datum of this map is the 1927 North American datum and then there are some other information on how to deal with this map if you want to transfer the coordinates that's very important information so before we proceed we need to look up this projection and get the epsg code so in open-source software we often use the epsg code to identify the projection it's very useful because if you work with people together you only need to share your epsg code and everybody works in the same projection if you manually choose projections you might have done that in your work then if you choose the wrong one it can be slightly wrong and it's very hard to to correct that afterwards so if you want to know the epsg code of this projection you can go to a website which is called your spatial reference dot org I'm gonna put it up it's this website and what we have read is that it's UTM it's sown 18 its northern hemisphere and it's North American datum 1927 now this is a search engine but not as clever as Google so you need to be rather precise if you don't know how to abbreviate an ID as a search term then you have to look and interpret this list and we see here an ad 27 that must be North American datum 1927 so if we write at them an ad 27 and our list gets much shorter and also this is a bit like in Google so you're looking for something specific but Google gives many pages back and this doesn't give many pages because we were quite precise in what we asked to the search engine but we still get three codes here and the rule is well don't look at what you're not looking for so we were not looking for 76 or cgq 77 we were specifically looking for this one so that's the one we need to choose when I click on on the link then it gives you some more information description I can download this projection information in all kinds of formats but what's important for us is to use this base decode so I'm going to copy into memory so I can use it in GIS so now it's time to move to kuja's I'm gonna share a cutie screen and what I'm using here is a qgs 2.3 point 10 the healthy heart versions are between three point ten point three there are newer versions but for operational use and especially if you are a lecturer you want to use a stable version where your course material continuously works so the newer versions are also quite stable unless you maybe use the nightly builds but they can have some things that have been broken while updating so - or things that work differently so for courses and for operational use it's always wise to install the LTR version that you can find on that you just at work so I have here an empty project and what I'm going to do is first install plug in and this is a core plug in so it already comes with kids so for this one for the core plugins you don't need to have an internet connection for the others you need and I'm going to look for the geo-referencer jido plugin it's here it's already checked here if it's not checked in your case you check the box and then it's activated and then you'll find it under the raster menu and there we see the dear reference or - if I click on it it starts a new window it's always wise to maximize it because we are going to use the space here on the screen to do the geo referencing it's not a good idea to do that on a very small part of the screen you can also dock this to QGIS and there are some settings here if you can look at configure geo-referencer the nice ones is like use map units if possible for the residual or units you can play with that and show G reference your window docked that is a nice one if you want to do image to image you're referencing I'll come to that later that's not covered but I'll show you where you can find how to do that and why you need to do that sometimes so let's start adding our picture to get back so click on this button and it's there chapter 1 of the book comes with the book data and there it is if you get a pop-up to indicate the projection of this map you need to click cancel because this map doesn't have the projection yet it is just a picture and it has the coordinates from the file you see them in the lower right these are not projected coordinates but that's just rows and columns in this file so what we need to do is a few things before we can start your referencing we can click this button to set the transformation parameters and if you don't know anything about the type of transformation needed it's always wise to start with the linear one so linear means that it's just a rotation and a scaling of the map if that doesn't give good results we will see later how to interpret the errors then you can use the other ways of polynomials for example which are more complex it fits through the points that you're going to identify the ground control points let's start with linear and see what happens then the resembling method so if we are going to do do referencing we are going to calculate new read coordinates and yeah the risk of that is that you know we need to resemble and you need to need to choose a resembling method and if you want to do calculations of the rules if you want to do calculations you choose the nearest neighbor if you want to use this map for visualization then you can use a cubic or cubic spline in this case I want to use it to digitize factors so I choose cubic if you have a satellite image and you want to do calculations or DM you need to use nearest neighbor by the way this is the way to do it for the roster data for effective data there are approaches I choose here cubic and then I need to choose the target projection and I'll do that with this button here you can choose the projection in some cases it's grayed out then you need a workaround and the workaround is published on the on the website of the book so you can see how to do that in my case it still works but I saw it many students that it doesn't work like this anymore so the trick is if it doesn't work that you set the projection of your project so I'm gonna paste here the epsg code that I found on the spatial reference dot org website so you can always write in the filter name of the projection but also the epsg code and then I can choose it and here it is you can see approximately where it is on the globe using this map and you get your textual description in the well-known text format and that's indeed the one we need so when you choose this click ok so now it's defined where do I want to save my output raster I want to save it in the same folder also note for good practice that we use underscores and not spaces in file names and the form is very important and yeah it automatically adds this modified gonna score modify to the found I keep it like that so to distinguish it from the original file not gonna change anything else here but I would like to change this one to check this box loading qgs when done that means that in the end after indicating all the ground control points that's what we're going to do that when it's finished it loads the results for this modified file in the canvas of cages and I can continue working ok so these are the settings and then we can start digitizing our ground control points and we do this with these three buttons so this one is to add a point that's to delete a point this is to remove the GCP to another location so we have found out that this grid on the map is related to that projection that we have indicated so we are going to read these numbers and we're going to identify ground control points on the nodes of the grid and we're going to use 4 so at least 4 are needed to do this a little bit accurately more is always better for this demo I'll use for what's also important is that you maintain a good spread over the map because the the inaccuracies of the hardcopy map they are spread over the map if you want to do reference it it's important that you spread your points over the map otherwise it's only accurate in one corner so I'm going to add the points when i zoom in I move it a bit to the center of the screen and you zoom in really well it's important this that this job is done accurately and I place the first point here in the center of the pixel and now I'm going to read the values from the side of the map so this is the X and that is the y so don't confuse them then your error will be low but you'll get an upside down inside out kind of map so that's five eight one thousand meters east and four eight eight five this is a real scant map so you can see that the resolution you see is a real thing it's not a perfect map because of the scan you see wrinkles here so yeah okay now the first point is set here and it fills in the source coordinates of the file and the destination in our UTM projection and the residuals I'm going to another corner here I'm going to use this one here you already see that the map was a little bit rotated during the scan comes a bit fuzzy so I'm gonna estimate that it's approximately here then I read the values from the side five nine guy remember that it emits it's the zeros because it's meter so I need to add the three zeros and the other one here four eight eight six zero zero zero and that's our second point I'm going to continue with a third point it needs at least three points to estimate the accuracy I'll show you know now you see already some residuals but with two points that's like standing with three people in a row if you were allowed again to stand in a row and then when you retweet people and to our outside and you say that the others are not in the route that doesn't make much sense so you need more points to determine what is in the right order so can use this point may mean that is this one if I make a mistake and put it here I have to type something let me put it here and then type the coordinates and I'll show you how to remove it so this is five nine nine eight zero zero zero and four eight seven three zero zero zero okay now there are few things you see it calculates now the residual because we have three points and with this red line it indicates the proportion of that error and the direction of that error and of course yeah with this button we can delete the whole point if I click on it with this one we can move it and I can put it in a better location approximately here yeah so I'm going to do the fourth point and see what happens with the residuals so don't base to quickly conclusions on two little points let's use this one nice one here and I'm at the point and then the coordinates are five eight one zero zero zero and four eight seven three zero zero zero okay there we are it's always good to check if we have systematic errors it doesn't seem like that you can always check if you miss a zero there you can easily make typos I've seen all kinds of varieties so this seems okay and then here it says the mean error which is thirty nine point six five six two pixels and that's a bit too large that's approximately this red line so for each point it displays the error with these red lines and this is an indication after checking all these points that we need another kind of transformation so if I go back to the settings I'm now going to put it on the first order polynomial I do okay now I see that the error drops to less than 1 pixel 0.44 it will still plot the point with the error and we find that one of the points here here so you see now that the error is within one pixel so that's acceptable you will not always achieve this accuracy so it's not a rule that the error needs to be always within a pixel sometimes it's simply impossible so it depends on purpose of your dereferencing so I've set all these points and I accept this element so we can start doing the dereferencing and you do that by pushing this button start geo referencing there we go and it gives here a warning and I think that should be okay this is in all the versions not the case but I'm just accepting it in this case has to do with some updates on the projection library and I can simply close this window it will ask to save the ground control points I could save them and here I see the geo reference map if it looks inside out mirrored then you did something really wrong in this case it it makes sense but now we need to check if it makes sense and yeah there were also some bugs with the projection in older versions of this 3.10 series so let's see if this results in the right coordinates now how to do that is what if I sample the coordinates of the point this point and see if it's that that's the same as written here in the corner I can do that with the coordinate capture tool that's also a core plugin so if you don't have it you'll find it here coordinate capture tool and you just need to check the box and then you have it here and it opens this pane here and I can click start capture a zoom in on this pixel and I click and the first one is Inlet longitudes and the second one is in our projection and let's see again if that makes sense yeah it's pretty close to what we have chosen so that's that's perfect so that's one way of checking so always do that never believe what comes out of the software always checking you can make mistakes to come in bugs another way to check it is to use an online map because yeah it will be very hard for you to challenge that the whole world was wrong and your map is ok so let's see how it looks like if we have a good Street map or the Google satellite in the background for that you need a plug-in that is called the quick map services plugin this one I already installed it and then it comes here in a menu at first you will see a shorter list and I have here on the screen so what you can do is go to settings you only have to do that once and then you go to more services and you click get contributed back and then you will have the list like I have it here so I'm going now to choose the OpenStreetMap and I use here the OSM standards and it will load to the internet and I can check in the lakes correspond you can do that by clicking space you can double clicking the spacebar now that's one way you can also work with transparency so here I clicked on this button to open the life styling panel layer styling panel and here I can play around with the opacity so I can see how good OpenStreetMap matches with our dear reference map another way of doing it is with blending that's something quite unique for our qgs so if I do blending on multiply you can see the OpenStreetMap true it makes it OpenStreetMap with this result another nice plugin is the map swipe plug-in where you can move around maybe leave time I can demonstrate that another thing to do to compare it is use from a bus from the quick map services to google satellite yeah so I'm going to remove for the Oak Street Map standards I'm going to blink the screen and we see that the lake is there and yeah makes sense you can also blend it so let's see what happens if I blend this it'll multiply now we see the satellite blended with the map that we do reference so this is a quite a proof that it's a good fit because if it fits with global data to Internet them that's ok okay now now we have a nice backdrop to digitize let's start digitizing there was the second task we're halfway and the webinar is 9:30 we have hundreds 57 participants everything's fine with you so let's start with creating a Geo package with points and what we're going to do is we are going to digitize a few of these mountains which have the elevation value with them there are some Peaks here and some have elevation values and things that you look in this corner here have a few here and we can digitize those points here's mom Marcy mighty some other mountains so let's start and go to layer create layer new Geo package layer so the difference between a shapefile and a Geo package is that in a do package well there are many differences so she fell is quite a common format which has a lot of disadvantages I'm not going to give a whole lecture on that but basically a dual package is a database and you can store points lines polygons rosters but even your styling and your whole qgs project in one file based database that you can share with others and with the shapefile you have to always share multiple files it has limitations to the amount of characters on the data management etc so in this case we can use geo package to also propagate the use of that so I'm gonna browse to my folder the webinar folder and I'm going to create a new database which I call Marcy and extension of the Geo package is GP kg so that's the name of the database now in the database you create your layers so our first table will be Peaks and we have to identify the geometry global points and we identify the projection and we can use this drop-down list to choose a projection that we've already used so this one that's over from our project so so here this is the only fly reprojection you can check my videos on projections if you want to learn more about that and the first one field so these are the fields in the attribute table the columns where we're going to identify our elevations first ionization that's of course not text data in this case no use a whole number integer and never forget to push this button many people forget it and then nothing happens because you need to add it to this fields list then another name that we put here is the name of the mountain so let's go just name there let me choose here text text data and I add it to the list so there are two columns here in the attribute table and I click OK now we can start digitizing so here is the panel we can click here on total editing so the peaks layer is now ready for editing and with this button we can add the feature so if it's points it looks like this if it's lines it looks like the line polygon looks like polygons the Foresta functioning is pretty much the same so let's do our first point here let's take this one it hard to read that's part of the game and it's just a demonstration so let's put it here it's our first point and it also generates the F ID so this is the feature ID and it starts giving it a unique number from 1 onwards and I can type here the elevation so 16 26 or something and I can give it the name mount I think it's Marcy okay so that's our first point let's do another one to repeat this so this one hey stick so again it also generates the ID with 1672 may be hard to read it's just an example you can of course read it from the from the lines if you interpolate them country lines haystack so we have here two points well you can now save it or if you need to delete one you can use the selection and you can select the point and click the trash bin then it will be deleted I'm gonna do that now you can undo things you can play around with that functionality I want now to unselect everything it's not selected anymore also remember that as long as you're seeing this pencil at the layer you're in editing mode so it means this is still in memory it is not in in the file yet so you need to save it now if you click save then it's stored in the file and almost carved in stone if you want to undo things better not click the Save button in general but click then the total editing and if you do discard you can continue from the last part safe that you you did so but in this case I want to save it so now the points are in the file if I click right I can open the attribute table and I find here the attributes and these are the two attributes that we have entered so that's what you can do with points so now I'm going to demonstrate lights I'm going to do a river part of a river and we're gonna do a whole river and the idea is to do some tributaries and let's do this part so I'm going to create in the same way a new your package layer I use this to select the database that we already have because we remember we can put everything in our deal package that we digitized so we can mix points lines and polygons so I choose the same database but now I call the table name rivers and I choose hairline don't forget to choose the right projection and I want the name of the river text data don't forget to click this button to edit here and that's basically all I want at this moment for the rivers if I click OK it gives this pop-up new package layer says the file already exists so do you want to overwrite the existing file with a new database or add a new layer to it obviously we want to add the new layer to the existing database so we click this one so now they are both in the database and I'm gonna digitize it and then I'll show you how in the end I'll show you how the database looks like by the way if I hover my mouse over the layers I can see the projection and I can see where it starts or it refers now to the montmarcy geo package database and the layer name rivers so total on the editing and here I'm gonna just start somewhere on this River make sure that also the layers on the top otherwise your digitizing below that's a mistake is often made enough to do this very precisely so better to zoom in well if you need to pan on your screen you can press the space bar and move your mouse so you can then easily move and continue there we go now the trick is to with rivers to digitize it from the upstream to the downstream and to put a node where a tributary joints because we're going to add that tributary later or in fact this is the tributary so I can now can stop it here and I can continue from that side it's just a matter of choice so if you use the right mouse button you can stop the digitizing if I do the backspace I go one note back so you see that I can do that yeah so I'll just stop it here then Auto generates the feature ID and I can right here just type Luke I know the name is a bit longer just for the demo I write your book we'll work on the styling later so I've got a bit of light color so it's a bit invisible I'm gonna now add this other one here but before I do that I'm going to switch on the snapping options because you want these rivers really to connect to each other so I click right and then there is this snapping tool bar here and I can activate it by clicking on the magnet and you can change it to a tolerance of meters and I can set it for example to 15 meters and here you can choose if it has to snap to all the layers or only the active layers I keep it on the default old layer system is the one relevant here here you can choose if it needs to snap to a vertex or also to a segment I wanted only to a vertex in this case near some other settings so now I've set the snapping and it means that if I come close to the point within 15 meters you see that it highlights so when I start digitizing from the upstream to the downstream and I come closer I'll just do this stretch here then it will snap they use the spacebar to then remember to do the bit rougher than you will do in a real case and you see when I come close that it simply snaps to this point these are voids that we have done in notes and undershoots or overshoots and then I can simply continue with this line little bit rough now and just have something and then you can give the name there let's call this one I also call this Brooke because I'm going to show you how to make this one River later so if your two stretches I call them Brooke and I can now save it or just toggle the editing and say save because I'm done with this and when I open the attribute table I see here two features if I select a feature it becomes yellow you can see it here we see this one is that this feature ID one and the other is feature ID number two now if I want to consider them as one I need to dissolve the two lines I'm gonna unselect these things and to dissolve we use a reflector processing tool it's called dissolve here and I'm gonna dissolve rivers I'm going to dissolve based on the name because if I give similar features at the same name I can use our similar ID or a number or letter then I can dissolve it so it becomes one feature with this function so that's what I'm going to do so everything that's called Brooke will not be one feature and I'm gonna store this to our geo package of course save to geo package and it's in a webinar fuller chapter one choose your package and I give the name River dissolve safe there you see this whole string being entered but that just means put it in the right to that place in the Geo date but in the new package then I run it's done and here's the result and if I check the attribute table we can see now that the whole thing is now one feature if I selected so that's what you can do if you want to have one River including all its tributaries being one feature and select it then the next thing that we can do is the lakes so take one that's not too big for this purpose of the webinar this is a nice small one I'll just give it a fictitious name just to save a bit of time so similar procedure go to layer create layer new Geo package layer I choose our existing database I'll call its legs I understood that you couldn't see the attribute table I think I need to change it to share the whole screen I think that's better so I'll just change I hope that was the only thing that you missed let me change it to the share the whole screen so I'm sure that you don't miss anything so you should be able now to see all the windows so sorry for not seeing the attribute table okay so we have here the legs and put it at polygon don't forget to change it to the projection that we're using and also here are just one name of the lake text data added to the fields that's okay that new layer that's what we learned previously and will be added to our database and I toggle the editing and now we can see here at the polygon and I can start adding the boundaries of the polygon I need a bit rough of course in reality you do this very precisely as an expert did you see that digitize and also depends a lot on the resolution of your scan so here it starts impacting and I click right to close the polygon and then I get this pop-up how to generate the ID and as a name I put here some leg that's got some leg there this is our lake and well sometimes here also we have lakes which have islands and what you can do is click right and go to the advanced digitizing panel I'm sorry we need advanced digitizing toolbar not the panel that's this one under toolbars here and here you have these options of adding a ring at a part fill ring etc so you can play with that if you have islands in your polygons so I'm not going to do that in this webinar so I'm simply going to switch it off and save this layer and what's left now is to to style it a little bit and it's very nice that Kurt explained that in the book so I'm trying to do that a little bit so let's let me take the book with me and let's go to the peaks and start all these points and the nice thing is that for styling these Peaks we used an SVG marker so let's zoom to this layer we see here our a point here that we're going to style Marcy and go to the life layer styling panel and what we're going to do now is by default it is using a simple marker but we are going to change that so I'm going to click here on simple marker and I'm going to choose here and SVG marker and cue just comes with a lot of preset SVG files these are vector yeah symbology and if I scroll down I see here the SVG groups and they're grouped per theme and I need the one of symbol and I'm going to use this red symbol there it is I selected it now and I'm just gonna change the size of this so what I would like to see is the width and height and 12 millimeters there it is and now we see that we have this beautiful marker on the screen and fixed to 12 millimeters now I also want to label these Peaks so I can go here to label it I have to choose the common the field in the actual table to use to label it but I can also open the expression dialog so I'm using here single labels and here I can choose the column or I can choose an expression or what we want here is both the name and the elevation so I'm going to build an expression so to click here it opens the expression editor and this expression where we have the name and it's good practice to go here to fields and values where you see the different columns that we have to the attribute table if I double click on name it comes in quotes double quote double quote means the column that we have in that retailer you see here the output preview that it says montmarcy this button I can concatenate strings which means I can connect it to another string which is in our case the elevation but I want the elevation on a new line and we can use there this string we can type it here if we want to type a string anyways we use single quotes so I can type here anything and I put it here under single quotes and you see here that it's added yeah and if I want to space a space before but I won't hear a new line and this is a special special character which is nicely food here in the preset button so if I click here I get a new line AC now it jumps to the next line and I want to concatenate them with with the elevation so go here to elevation if I double click put your elevation value and I also want to have the unit's there so I'm going to use a single quote and a space space is important then there's a space there now I have it in meters so this is basically how we can add a new line and the string and combine it with our columns of the absolute table so that looks okay there are other kinds of things we can do like formatting the numbers etc it's covered in the book but this is so this basically what we only have here and of course now we need to make it need to make it a bit more visible so what I'm going to do is go into the font style here and make it bold now it's bold and so I'd like to have it a little bit bigger I'll do that later so we're going to use here label buffer here and I draw text buffer so it becomes a bit clearer and are readable and I'm going to give it a bit more space by using this button injera can set a distance of two units for example and now we see that it's nicely placed next to our marker there are some nice hidden options here a lot of hidden options in the in the label generator so if you go here you have automated placement settings and what you can do here is to allow to disallow truncated labels on edges of the map so if I just uncheck this and then if it goes to the side you see now it jumps so it makes sure that all your labels are still visible even when they're on the edge of your maps it's a nice option qgs [Music] yes so that's basically what I would like to show for the styling of the Peaks now we can style the rivers in a few minutes for that I'm going to use this dissolve one go to the styling and there you're going to click on simple line and there are very many types of changing your colors here but if you click here on the color then you can put an RGB value and in the book we have used this combination to get a nice blue line for the river and hundred and eighty now we have this nice blue color we go back here let me zoom to a river there now you see it's blue but it's still bit small so we're going to change the stroke width to zero eighty six and now we have the river in bigger blue so lots of things you can change here and then we go to the labels want a single labels and we want the name of the river now you see it here group and yeah what is nice about the placement option for the river is to put it on curves and a book is a bit a short name but if you have a longer name it will curve nicely around the river so that's a nice thing you can do and to make it more readable you can also change the buffer color that you put around it so we'll draw a text buffer here but it's white so it's still quite prominent and the background is mostly green so I can go here to the drop down of the color and I can choose here pick color and now I can choose the green of the map and you see that it's now a bit hidden this buffer and it comes really nice out of of the map so that's a nice tip if you want to use this buffer use the background color of the map okay then I go here to the text and also we want the color of the the text to be blue because that's nice for the river so can use the RGB values of 31:38 and 180 here and now our rivers have a blue label also nice to change the fonts so we can use here Cali Bree or something I want to be too fast and we can change the size let's make it a bit bigger which is 11 and make it italic so these are things that we can simply change there and the last few minutes I'll spend on styling the lakes so let's switch to the lakes so him you can always see which layer is selected and I'm going to style it so I'll go here and choose again this simple fill and in this case I'm going to use the shape burst fill of course it's good if we would see now the lake that we digitized it's here and you see now that the shade burst fill has this gradient kind of fill and what we're going to do is to change these two colors that we use we are going to use this to color shapers fill and this first color we're going to set to so it needs to be of course blueish like with lakes that make sense so we use 3133 and hundred and eighty here so that's nice blue and for the second color sorry that was for the first color I have to switch it around so let's do that again live demos the book next to me boys exciting so one hundred eighty five two three nine and two five five for this one then for the other color you use thirty-one 33 and 180 so now it already starts making a bit of sense but it's not completely what we want so let's change here are some parameters I would like to use a distance of six that always works well and I'm gonna make a blur strength of 12 and you see now that it's a nice blurred Lake but we also wanted boundary around the lake so I'm also going to add a second renderer here and and there I'm going to use a simple line and then for that line I'm going to use also a blue color so I'll use here 3133 and 180 the same as the second color that he had so then the outline becomes also clear so you can play around with these things let's also label the lake like we label the other things so I'm going to use a single label here and I'm going to use the name fields it's already selected and I'm going to set the label color there too also to blue so I'm going to use 255 255 255 and that's right sorry I wanted to why it's because then it comes nice out of the blue and there I'm going to set the size to 10 points keep it like this I'll style it bold and italic maybe it's better bold and italic I can't use that so you can play around with these settings to to make that nicer change the placement horizontal now it gets nicely into the lake that's a nice option there and [Music] if you're late names are very large then here's a nice option on the formatting where you can choose a rep on the on character see where that is here you can wrap it on the character if you want or you can set it here so there are different options here you can complain with lots of options actually and that's basically what I wanted to explain to you so you can always save your project all the time you can save it even to your geo package something new in this version so let's see if I can use it here Marcy and I'm gonna give it a new name let's call this Marcy maybe webinar 1 ok and now the project is saved in the Geo package if I go now to the browser panel and I go to this folder for the webinar then chapter 1 and I find here our database and everything that we have stored is in the database even our project and I can even put the roster of my Marcy in the date of I simply drag it there and import was successful so now also our geo package has the Rustler in it so it contains rusty reflector everything we can even put our styles and every double come another time so I'm gonna go back to you guys and I hope things are going well let me invite quark back let me see if I can unmute him Hey hi I didn't go we're there many questions was it visible what is the experience of the participants well it looks to me like it came through very well and there were there were a lot of questions that I answered along the way so we had a good active discussion going while you were showing us that I do all that great yeah I think it went very well that's great good to hear that any general things you want to summarize occurred from the chats no just to mention like you did that this was a very quick run-through of that chapter and there's a lot more detail in the actual open courseware or the exercise out of the book so I encourage everyone to go through that in their own time if they're wanting to take a deeper dive into this mm-hmm great yes that's good advice I think we can also go to the slides where we can recommend a few trainings and talk a bit about book so I'm going to share the presentation back so first of all to repeat that 22nd of March is World Water Day and you will get 30% discount on the e-book from now until Sunday if you go to locate press come slash kid and you use the code qgs hydro you get 30% and it's really nice to have the book next to this webinar to to follow the steps there's also more that we have so there are all kinds of course free course materials at ihe dealt with our open courseware so there's the website GIS open courseware at work I will share the screen and show you where that is that's here so here you can find all kinds of free materials including exercises like the one that we did but not as good described as in the in the book there's exercises on jido on Python and field surveys with input immersion and I really have to mention that I'm so happy that Lutra consulting sponsored this session to go over hundred participants and we see that I was really necessary because we have at this moment hundred forty-four concurrent participants so that's really great and Lutra consulting has developed the 3d viewer of qgs the input and the merging application for using the fields and synchronizing definitely you're worth looking at and there's also a collection of video tutorials here organized in lay lists and my youtube channel you can find many more videos with instructions also for this exercise that we that we did so have a look it's also about a Python a PC rester and yeah hope you will enjoy those let me switch back to the other screen so what we also have it ihe is short courses for professionals like you we can there's one that's called futures for hydrological applications and that Kurt has been with me doing that in the last two years and in the last one we had a lot of fun also doing mapathon and presenting our book so the next one will be from 14 to 18 September in in Delft so if you want a course that is certified you can come there and stay five days with us if you need more information go to the IHC Delft website or contact me and I can give you the information the links are also on the open courseware website these are paid courses but you will get support and you'll get the official GED certificate another option if you don't want to come to delt or can't afford it or the corona crisis going on you can always do online courses and we have an online course together with new LAN geo-information if you want to do that one you can also get the official certificate then you get support it's not only a basic course together with court we will develop over the next weeks also a full-blown online course on Jesus for hydrological applications also stay tuned on that of court also some nice stuff to tell ya so in the shameless plug department here and given that what we're all facing right now with this Kovach crisis I've developed a program over the last several years called Community Health Maps and this is part of democratizing technology so this is using all open tools like Q just to help public health workers and communities manage disease outbreaks and any kind of health concerns a community may have so with picking inspiration from Hans getting this webinar going I'm planning on setting up a series of webinars that go through the community health maps workflow for people in the next look for that in the next month or so I'll make that available so the the website is community health maps org and there are there is some OpenCourseWare on there and an online tutorial as well and this is showing people how to do various things collect data with a smartphone using things like input or cue field or fulcrum then bringing that data into QGIS to do some spatial analysis and mapping and finally using something like mat box to set up an online web mapping platform with the data that's collected so I'll be setting up something in the next couple weeks so look for that very nice so go have a look at that it's really great so what we'll do next week in this weekly webinar is going to explain how to import tabular data like Excel sheets into qgs somebody's drawing on the screen to join attribute tables and to interpolate points to raster so I hope you also join next week and keep the hash tag you just hydro if you want to communicate on Twitter about this and yeah if you need anything from Curtin Mead and you can stay in touch and so Media in the meantime and I would like to invite you all for the Geo beers now that's something that we have in the Geo world that we have drinks together and chat about everything in our lives including of course a lot of Geo and in this time of the kovat crisis here on the kovat online campus we're gonna do it online so if you want to join us and yeah I would like to beer with you a drink and so Cheers I'll mute you and let's see what happens video recording here [Laughter]

Channel: Hans van der Kwast

Views: 11,702

Rating: 4.9815669 out of 5

Keywords: QGIS, webinar, QGISHydro, georeferencing, digitize, vectors, geopackage

Id: hPLqy-NBgu8

Length: 67min 3sec (4023 seconds)

Published: Sat Mar 21 2020