#84 QGIS for water modellers

subscribe to this youtube channel by clicking the subscription button below for future webinars and online short courses please visit our website at australianwaterschool.com welcome to this australian water school webinar brought to you by ice warm this webinar series engages water sector thought leaders globally thank you for joining us today to discuss qgis for water modelers it's going to be presented by saber resin dewey craig price and harness of underclass my name is trevor pillar i'm the national partnerships manager here at ice warm and chair of the australian water school webinars it's so good to see you all look at that map on the screen there that is just awesome thank you for joining us we're going to have a great discussion um attract the global spread of attendees from many countries as you can see let's get into this the presenters today three of them are you coming on screen um saba cray hans that's wonderful if you do that'll be fantastic good morning good afternoon good evening let me introduce you first i see your faces and that's good at least we're connecting across millions of kilometers not millions sava rosman dewey is from lucha consulting he's managing director silver holds a master of science in water resource engineering worked in the water sector in the uk for 10 years and started lutra consulting he's one of the core developers of qgis great to have a core developer of qgis with us today free and open source gis application secondly craig price from surface water solutions educated at university of california craig wonderful berkeley craig's a civil engineer project manager with international experience uh i could read all that but you know what craig your reputation goes well before you wonderful reputation includes 15 years developing hydraulic models for the u.s army corps of engineers and recently provided training to over 500 course attendees using the newly released tech press software hans van der quest is with ihe delft institute for water education a senior lecturer in ecohydrological modelling um holds a phd in physical geography um and i won't read the whole lot he co-authored the book qr qgis for hydro hydrological applications gentlemen nice to see you put your mics on we want to hear and see you yes we can here we can see you uh okay you're from where oh i'm i'm in perth now bright and early in the morning here it's 2 am or something unearthly not that bad but the sun the sun's just coming up so i can see the sun in the background in your window that's fantastic and um saba you're in europe somewhere yes i am usually based in uk but at the moment i'm in slovakia bratislava hello to everyone coming through loud and clear wonderful enhance your in netherlands i understand yes i'm in rotterdam in my house wonderful tell me what motivates you in one quick sentence then we'll get straight into this uh cry you go first well i think we broke a record here and the word is free um so i'll i'll keep it short sounds good and saba what motivates you to keep keep this this this modeling qgis track running uh mainly because i was a modeler and moved to qgis so i thought it would be a good story to tell it's a fantastic story enhance spreading the word that qgis is a great tool for modelers in in everything to do with water it's certainly got a big following delay i can tell you that gentlemen thanks so much for joining us what else do we need to do before we get underway i think we'll just leave it right there and hand it over to you crain unless i've missed something in this introduction it's been a bit fast but once again everybody keep your questions coming in the q and a line use the chat line for just talking to each other and we'll get right underway now craig's going to take it over then hand over to saba and then over to hans thanks very much craig awesome okay well the first question always give me a thumbs up if you can uh see my screen and uh make sure that everybody's able to see that hopefully we've got a good connection on the voice what i'm going to do is actually do a live demo on a couple of basic features of the raster calculator so i'm going to put this presentation away but if it gets slow because or if there's a delay then i'll just go with the static screen um so yeah my name's craig um in the past when i've introduced myself a lot of people think my name is craig and so i've said cray as in crayfish but today we are going to learn about the crayfish plug-in for qgis and uh i i've been using it for years um had nothing to do with the development of it but uh now i'm excited to be sitting on a webinar together with uh presenting with some of the people who have uh contributed to the development of the crayfish tool along with a few other things now um what uh what would a hydraulic modeler or a water modeler want to use a gis tool for and i want to talk about a couple of basic things i only want to take about five minutes here and then turn the bulk of the time over to sauber and then hans will uh follow up with some uh resources for you now one of the most common things that you're going to want to do in a with a gis tool and water modeling is delineating a catchment now hans has got some awesome videos online he'll point you to those resources you can even just google catchment delineation and qgis and you'll get to his videos so we don't need to cover that in detail here today also a month or two back we did a hms uh webinar where the new version will build you a basin model automatically just straight from your terrain for free and people who dig free uh hydraulic modeling software dig free uh gis software as well and um i think our top seven videos already on uh webinars for ice warm have been hec-ras so i'm gonna show you right here you've got a hec-ras screen in front of you i'm gonna demonstrate a couple of basic features of qgis and in hec-ras or any other modeling software you're going to be able to generate an inundation map so the output is going to be the outline of this map that could be a depth map it could be a water surface elevation map but what if you wanted to see the difference between them and that's a fairly simple thing to do in qgis but to introduce this concept i'm going to go back here let me back out to central park here i just did a course in new york a while back and we used the free new york one meter dem data which is awesome um i just unleashed a flood across central park here and um we wanted to see the impact of putting a building in um and so what we've done then is built in a building here i'll show you that um if we turn the boat house this is where in the movies uh people float around here in the uh in this lake um on on their love boats um if we turn that boat house into a box warehouse and then did the same thing and ran the exact same flood through um what would happen uh to the to the flows okay they'd be backed up here and they'd be less there but what are we going to do with that now so let's open up qgis and i'll pull in the new york city model here and just show you here under the raster calculator if i take my raster calculator and i take my after that's the terrain that i've loaded in this is after i put the building in and just use this little minus button here and then say before and i subtract those i put myself in a name here difference map and then when i hit ok and i'm going to come back in here now and uh show you what the result is i don't wait for that to finish just in the interest of time i'll show you what we've got i can turn on now the central park terrain i'll turn this down so you can see it in grayscale turn off my results and only look at this raster map and this is what just came straight out of qgis a couple minutes ago i just generated this it took like two minutes to do it but you know it doesn't take long at all um in this case i can hover around now and i'll show you then as a result of this building as i hover around here i had a two meter backwater here effect of the building that's blocking the flow and it tapers back out and then comes back down to zero and i've got a shadow on the other side now the term a flux mapping isn't all that common in the us but elsewhere in the world um you can't get a floodplain development permit without an aflux map so that's a difference map so that's one simple thing um the second thing i want to show you and again i'm stepping through this fairly quickly but the recording will be online and available if you wanted to pause it and have a look at what we're actually doing here for the second case i'm going to show you a dam and we've just completed uh a course for ice warm together with chris goodell i was excited to finish up a course on uh dam breach modeling and um i'll show you here one of the models that we actually built uh which is a little bit absurd i will admit but um just because we can get free terrain data anywhere on the planet uh we've got san francisco here um lake the great salt lake up there and then the grand canyon down here what we did in this particular course is to zoom in on the grand canyon and between lake powell and lake mead where we've got hoover dam and glen canyon dam we'll go ahead and build ourselves a new dam um so what i want to do is use qgis as a terrain modification tool in this instance now if you were an old-school uh dam designer 100 years ago now you would not want to inundate the grand canyon obviously but if you were out trying to develop the us wild west where would you put a dam and we can pick anywhere we'd want this is free terrain data and we can scale it up or scale it down as we see fit what i've done here is to just build a quick geometry showing uh i just drew this line here for a river reach and then i automatically generated these cross sections at regular intervals and this is where i'm going to put my dam and when i've done this i'll pull over my terrain data and again this is this these are very quick steps that you can do in um just you using heck raz's tools but what i want to show you is what happens afterwards so as i'm scrolling through these you can see i've just pasted this same trapezoidal cross section everywhere for this dam okay sometimes it's underground sometimes it's above ground i paste it in the same thing and then i come in here in my geometry tools right click on this and export the layer as a as a geotiff now i can get into qgis and in qgis i'll pull this over for my grand canyon model i have this new terrain surface and some of this is below ground and some of it is above ground but what i want to do now is use a little tool in here in the raster calculator that takes a little bit of it's almost like programming but it's fairly straightforward what i want to do is write an if then function and so i'm going to put this in parentheses and i'm going to say if the first terrain is greater than or equal to the second terrain so greater than or equal to uh the the second terrain here um that's an if then statement and if this is true it'll be a one and if it's false it'll be a zero so if it's one i want to multiply this by the first one well now i want to add that to the same argument but in reverse if the second one is greater than or equal to uh the first one so greater than or equal to the first then i want to return a value of zero if it's false and one if it's true and then i'm going to multiply that by the second one and now i've got a valid expression i give it a name and this is going to be my max this is just basically a maximum function you could do this as a minimum and when i hit ok i'm going to go in here and show you the results when i pull this back in i have this now emerged terrain data set here where you can zoom in on this and you'll see then that this has gone underground see it's a bigger slope down here if i cut the slope right there across the river i can see that i've gone up and back down again into the river and then i can turn on and run my dam breech inundation map and i'll turn this one off here and now you can see what happens when i've blocked the grand canyon with a big dam all right so that's just two basic functions i wanted to demonstrate this is raster calculator it's been around for years um you don't want to hear what's old in qgis you want to hear what's new and that's why we've got the developers on these are the guys who wrote the book so i don't want to take any more time with that i'm going to stop my screen share i'm going to watch the chat line hans is going to watch the chat line while saber is talking and vice versa so we want to make sure that we find out what's new and these are these are awesome tools these are things some of which are built into the hydraulic modeling software already uh others don't have it yet and maybe it's coming but in the meantime these are a couple of tools you can use so i'm going to stop my share and turn straight over to sauber uh thanks great excellent uh good morning evening uh everyone ex i will start with the qgis what qgis is and where it started and then hopefully i'll go through the same some of the same workflows that craig showed you and convince you that you can do everything in qgis and you don't need to switch between glass mapper and qgis excellent i'm from lucha consulting we are a company core developer we have done qgis 3d mesh layer which i'll go in more details also we have got to uh input an open source mobile application which is based on qgis so you set up your project in qgis and can use it like collector with input which hans will touch on and mapping which is a qgis server for publishing maps uh i'll go through the background of qgis and how you can use it for pre and post processing platform then go through mdil where it started and how it can be useful for your workflow looking at qgs 3.8 and 10 for the mesh layer support and the upcoming development for 3.12 and 3.14 qti started as a post-gisbu which is a geodatabase then in 2002 that was by gary sherman and then in 2003 it was uh it supported huge uh plugin in 2004 microsoft windows was available 2006 available for mac and apple users 2007 support for python plugins and the first of release for qgis one was in 2009 and some of other key features that was developed for qgis was qgis server in 2010 qgis for android unit started in 2011 and ugs 3d in 2010 native 3d in 2018 and in 2019 uh it was ported to ios as well through input app uh so for modeling uh there is a bit of a parallel lines for qgis as well in 2005 there was a native support for grass gis for those of you who are familiar with in 2012 we started a two-flow viewer called crayfish plug-in and in 2013 the post-processing tools which contained saga totem odb otp and grass a bit of background about crayfish crayfish was a plugin we started our own consultancy and we didn't want to use sms for those of you who are familiar with so we created a custom renderer for qgis 1.8 and then for qgis2 for loading data uh to flow data mainly but um when we wanted to migrate it to qgis three it became a bit of a problem because it was a custom renderer and uh there are lots of interest from the community to have a native uh display for mesh layers uh directly in qgis uh i'll go through first what mesh is uh it's not about point cloud cloud it's about grid data to start with and uh you are familiar with some of the concept of gis like vector data vector data consists of uh two um components one is uh geometry another is attribute table uh you have got also rust data where you store values in pixels like terrain models uh craters display showed you these pixels uh one meter five meter they can contain elevation and it become a terrain model or elevation model but uh what about numerical models like hydraulic model output where you have got uh mesh data where values are stored at edges or centers how do you represent those in addition you might have even data and the loss like velocity component vector component on the edges to do that there have there are some ways of doing it or there were some ways of doing it by converting the grid data or mesh data to regular grid to a raster or contour it and display it as a vector but using those two methods uh it can create interpolation and explanation and it won't represent your data correctly because if you think of this mesh the data the results you get out of your hydraulic model they are um uh calculated at those points or centroid of those cells when you convert it to gridded mesh uh to grid at raster those are not anymore the calculated points and it can cause inaccuracy this this might not be very critical for flood models but for uh weather data that can be very completely out it's somewhere frames or somewhere doesn't rain in the forecast models when you convert the data with this method uh and also mesh data as i said can contain other dimension as well they can be time components to it so each cell can have quantities and the quantities will change by time if you think of a flood model the depth value changes by time and it can contain multiple quantities like depth velocity uh water head shear stress all sorts of model output you can store inside the mesh for that uh we introduced a new library called mdal mdal it's uh it will do what uh gdal or ogr will do for other gis packages if you think of arcgis or qgis they have got a built-in library uh called gdal or sorry not built-in external library called gdal or ogr which will handle all reading and parsing the vector data so we created an this mda library to look after the mesh data and then introduce that library to qgis to display the data the mdal data it follow contain for data support i'll show you quickly the formats it supports probably these are not of your interest these are the formats that mdulk currently supports uh 2dm data which is usually two flow or basement or some other data net cdf group data for weather data you get uh in this format xmdf or an xdm f that files 3di u-grid flow 2d um telemach data hacras anuga saga flow and to flow fv 3d data so it supports all those data you can natively open those data in qgis and view the data in addition uh mdall indexes the data so it loading the data becomes very fast and also it has got lazy loading so it will load the data on specific time step as you need it so it's very enhanced and it will be much faster faster to render in um qgis so i quickly now that craig showed you a demo can you all see my screen okay a qgis and that's um uh hacras data so i have loaded the hacras data here and you can see uh it parses bed elevation water surface and it passes also the special maximum values as well it has got here we don't have any velocity component and these are the time slider for time component so you can just directly zap through the time or play the time and see what happens in your model i have you can see that and you can change the style of the layer if you want to have different color scheme you can see the cells as well the um the grids from rust from your model and this can be done for any model aircraft to flow um and flow 2d and other that i've shown you in the list the only one major one missing from this list is dhi which we are hoping to get on board but with no luck so far and as you can see you can load your terrain data so you don't need to switch between the two models in addition to that we have added also mesh calculator which is very similar to what cray showed you but it has got additional uh filtering for uh time so you can do calculation based on the time and also it has got aggregate uh functions if you have got like uh face velocity you can calculate the maximum phase velocity or average etc from uh here as well and you can do all calculations between different time steps within here as well it's very similar to a grid calc raster calculator but it has got a functionality to carry out the calculations on meshes in addition to that we have got a crayfish plugin that you can animate the data you can create animation and also it has got a plot option so you can plot data so if you want to see the uh flood depth you can just move the mouse and you can put multiple point and you can see the color of the map a color of the graph shows you the color of the point here you can have cross section you can actually have aggregate cross section and calculate flow through the section as well so these are the integration of mda library within qgis let's see how i'm doing with the time and as i said you can show the trace animation uh also the velocity components i skip the velocity component this is the new feature which will appear in qgs 3.2 so you can create trace animation or streamlines and filter the velocity vectors as well to the way you display it or display weather data so if you have rainfall data or other types of temperature data you can directly overlay that on your qgi your hydraulic model output as well this is the flood data i think it's a two flow model so you can animate it and also debug your models it's not only for post processing you can also use it for debugging um uh mesh calculator as i mentioned it supports both cell center and data on the edge and crayfish for creating plots or cross sections uh and also mesh frames for 3d we have done some experiment with 3d view but it's not complete you can just see the topography in 3d uh so this is the summary of the how those three things sit together mdal is a data input output so whatever file format hydraulic output you can create you create you can pass it to qgis and then qgis renders the data and you can do mesh calculation and with crayfish you can export them to vector or export them to animation or plot data uh upcoming features for qgis uh a three-point uh 12 and 14 so the 2d mesh is this one that i've shown you that it's available in the current qgs 3.10 we have just implemented layer 3d mesh that's for 3d models like to flow fv or so you can create slices of data by averaging it over horizontal axis that will be available in qgs 3d in february next year uh yeah and we are going to introduce 1d mesh like pipe network in qgs 3.14 so that will be june uh 2020 and fully unstructured mesh that's not funded and we haven't got any plan for that but if anybody has got some spare cache we are happy to implement that uh then trace animation as i mentioned it's been done the in qgs 3.12 mesh calculator for hacras data now it supports hecras data for 3.12 export to contours in the current crayfish but you need to upgrade to qgis master or wait for qgs 3.12 and the layered measures perfection and for mdol uh point six we are hoping as i said to them have one decreed 3d meshes a bit more uh enhancement our error handling and converting data so you can convert hecras data to to flow data or to flow data output to you grid and those kind of conversion from command line and a global time manager we are working on for qgis and the things in our wish list that's as i said we need extra funding data streaming that will be enhancing the performance of rendering data that will help a lot more formats and standards uh we have got uh also we would like to do more write api at the right it supports a couple of formats but we would like to have it for all formats and potentially an api for python or r so you can interact with mesh directly from programming languages like python or r and that's my our contact details if you have any questions about any of those formats or if you need to know feel free to contact us directly and i can pass it to their hands which will talk you through some of the features of the processing toolbox i mentioned and also some extra tools that can help you with your hydrological assessment saba can i just hunt can i just have a moment in the middle um thank you for that wonderful presentation millions of questions coming in on the um on the q a line keep them coming everybody try and use the q a line only for the content of the webinar and use the chat line just to speak to each other that's fine um but i just wanted to say that the uh that we are planning to run courses in what we're talking about here in 2020 so keep your eye well and truly uh fixed on the um on the ice warm australian water school website website uh christy will put that up in the chat line you'll see that in a moment um but any other thoughts from yourself craig before we go to hans no no i'm just frantically typing here that's uh 441 answered questions already so yes um i i i'm gonna need to go back and watch uh cyber's uh recording because i've been looking at the chat line so uh same thing while hans is talking i'll keep watching that in cyber if you can watch that as well there are some questions there that are directed directly at you so nope i'll stay quiet here fantastic same of mine all over to you hans thank you for joining us wonderful okay over to you thanks uh maybe maybe we can uh ask a few questions to saber that came up that i wasn't able to answer maybe if i paid better attention to the video uh to uh to his presentation um one of the questions that i found interesting uh that came up is uh can you read the outputs from these qgis tools that you have developed also in arcgis to do that we need to yeah to need to to be able to do that we need to convince esri to use mda library mdal is free and open source on their mit license so they can technically take the mdl library and integrate it with esri and read their data actually recently we have incorporated a team format from esri so adf formats is now compatible with the mdal as well but the other way around we don't have any control there was a question from uh from uh abhishek gupta about loading 12 d8 data directly in qgis i've been googling a bit while you're talking and there's uh yeah there are their executables they've converted to shapefile but directly i don't think that's possible yet not yet as i said we will be very keen to talk to those vendors and add their formats to the list so they can be natively supported in qgis so if you know somebody there or as a user i would appreciate if you put some pressure to them to move and i saw a big discussion on on github also about also related to a question of one of the attendees about the dhia formats that are proprietary and you are not able to implement those formats unfortunately not because they have got a specific sdk to read that but the mdal is platform independent you can run it on your mac os or windows or linux but uh dhi is only specific to windows we have had some the conversation and i'm hoping if anybody is from dhi can get back to us and see if we can we can implement their format it's very popular and there are been lots of demands from their users okay i think uh that was about it for the the questions there were many questions and and we answered them but i think if you still have questions uh they can be answered also by by saber and also after of course this this webinar um so i'll continue um so i'm gonna share my screen because i'm gonna talk you through tutorials to learn about qgis for hydrology and hydraulics and we've seen more advanced stuff with uh with crayon with saber but yeah where do you start when you want to learn uh qgis and you're in the field of hydrology and hydraulics and um well there's a lot of open educational resources available there's open courseware that's completely free uh online courses there are free tutorials offered by many people in the world and there's youtube channels that are quite useful um we at iit delft have created gis open courseware.org and that's a good starting point if you go there i'm going to share another screen for that oops seems get back to my panels of this share if you go there you get on this website that's our opencourseware platform and a nice starting point if you go directly to the video tutorials and there you find all kinds of lectures on gis theory of course a lot is related to to water but also basic concepts but if you want to learn about catchment delineation the theory and this is software independent almost then you can learn it here um there's specific topics also about styling a map design for hydrological maps here's a catchment map and more advanced topics on how to use python and gdal and pc raster for hydrological modeling and a lot of exercises that are used in my class are explained here in videos also on a catchment delineation on importing data from from spreadsheets tables visualization using the tools of lutrac consulting for example to use the the mdol for that how to use open data a lot of us work in areas that are data poor and how do you deal then with with data there's a lot available on the net and some already mentioned the the input app there's also videos on that i've also added to this playlist videos from lutra consulting i'll go back to that later so these video tutorials uh give you a quick start with the qgis for many hydrologic applications now there's here uh in the general tab uh you find the general information let's see if it goes there yeah on the course you find some other resources here that you can use books etc and blogs now if you want to start doing a course on your own without a tutor then this list gives some of the basic topics that you want to start with related to to hydrology and you can find all the course materials here in a pdf course data and youtube channel and more videos and then for more advanced applications it's very wise to learn gdal if you want to do batch processing for example you get a lot of data out of your models that you need to convert in terms of projection and different uh formats and there are exercises there it starts with dos and continues with g dot dos or or linux bash you uh you also need to learn if you want to do scripting and it has a nice exercise on the batch conversion of a model output 30 years of output from a land use change model then there's a the next step in in boosting your gis career with open source stuff is learning python and there's this one day crash course for free that you can do learning all the concepts of python 3 using a jupyter notebook there are some lectures here in pdf but there's also a lot of nice other resources uh around made by others so if you want to learn about pi cuties uh you can use this nice tutorial from anita grasser and uh jeff gandy also has very nice tutorials hatari labs especially interesting for you working in groundwater lots of blogs posted and lots of videos from montana really does a great job on that i also like very much the work of jake thunder plus on the python data science handbook if you want to learn about uh scipy and pandas and all these things numpy so a lot is around there's also books from locate press about all these things it's very very useful too and as people in hydrology we also want to go out in the field and measure things and then lutra consulting has developed this very nice tool set which includes an app that we can use in the field it's called input and it's synchronized with the merging cloud servers and we set up our projects in qgis and together with saber i've developed this complete tutorial it has videos and if you go here to the tutorial you can see here it's about setting up the project adding the layers you want to use on the mobile phone and seeing how to synchronize it with merging and then how to capture the the data in in the field using these forms so uh quite complete and uh yeah really nice stuff that they made for uh using qgis in the field and i'm going back to my powerpoint so there's also this book that was also mentioned in the introduction so uh kurt menke and myself we wrote qjs for hydrological applications recipes for catchment hydrology and water management and it covers very similar topics as the open courseware so you can also do a lot for free but it has some nice new features that are added and there's specific attention for advanced styling and map design and a very nice thing if you you buy the book is that you support uh my students to go to phosphorus and cuties events and uh we have a bit of lack of diversity they're all most of them men from europe and we need more women and the global south participate in the open source way of working which is very nice and especially for the attendees of this uh webinar uh the publisher gary sherman also one of the founders of qgis offers 35 discount on the e-book if you use the code aws 2019 at ihe delves we offer also face-to-face training so if you're interested in learning more about qgs and hydrology and hydraulic modeling python then look at our website and hopefully i can meet you at ihdl what's also nice is that both lutra consulting and us we are licensed for issuing the official qgis certification so here on the picture you see our participants with official certificate and in that way our institute also supports qgis it certificates 20 euros so everybody's happy we can issue official certificates the participant has an official certificate and we support qgis so looking forward to to hear more from from you thanks fantastic hunt thank you for that and so much available out there to um uh to pick up on qgis um look we've got one hand up at the moment i think we might just take that so that your kuwu are you there maybe you can come on screen now um and have a quick chat i can't see sibichu coming on yet um here we are there we go far away far away over to you sovichy yeah i'm here ah good where are you from okay this is from nigeria nice to have you on board thank you so much thank you hans van for that wonderful presentation you're welcome okay um actually want to ask um based i'm actually doing a professional program in water resources management and i want to start a project on um from some areas in the southern part of nigeria where i need to use some software application and why i used to software applications to um help them analyze the impact of water scarcity and i'm using gis and swap but now from your presentation i think i have learned something that will make it a lot easier okay i'm asking now through this program do we necessarily need to use a programming language to interpret the results or can it just be done with just the qgis that is one and secondly for proper usage of the software do we have access to some of your youtube channels free or do we need to subscribe for that because that will help me personally to learn more things that will enhance the usability of that um software and applying that location thank you hans you can come on screen if uh if you can and yeah that question a comment yeah well it always depends on uh on your requirements which tools you're going to use so uh in in many cases it can be complete overkill to use programming languages although that's a very useful skill to have if the flexibility of a graphical user interface software models is limited so qgis is particularly good in pre-processing and post-processing your data and visualizing the data the real modeling itself you will do in a modeling tool that you either made by yourself or that you use such as hec-ras or swat and you've been using swot in your case what i always teach to my students is to make an evaluation in fact a good justification of which tools you want to use and that starts with writing up your requirements and also the restrictions like the data availability i see many people using a very complicated models that we use in uh in areas where we had a lot of data and which simply don't work in areas that are data poor so useful exercise is to simply list the requirements and the goals of your model and then choose the appropriate tool look what we might do uh craig would should we go to abhishek's question here are there any plans to create pipe network would that be a good direction to go in next there's a couple of hands up i can see thank you for those hands mateo and dodo but i reckon this question might be the one you want to look at oh yeah this was discussed briefly um online and so i think um cyber might have might be able to answer that one uh are there any plans to create pipe network analysis tools natively within qgis seems like an industry right issue and there are subpar solutions to these problems things like automatically setting up pipe directions inverts and linking inlets and outlets i think you could easily get funding for this tool as most firms have internal solutions to these uh i think there is already a plugin for qgis which is called q what right you what for water so if you have a look at that it should and it has got some integration with mod flowy from correct hands that's one tool but for post processing we are um implementing uh u-grid 1d so you can see the results in your qgis for example if a pipe is full or not or color the pipe based on the flow or based on velocity or depth etc and sorry to trevor general there were several questions generally are you going to support that or other formats just uh the way open source works each feature needs to be funded by an organization ideally those formats we have supported like the great work bmt has helped us in the past couple of years if other organizations are interested they can contact us us or other open qgs core developers and those features will be added so it's it's the way it works that sounds good um thank you doodoo for your uh comment there in the q a line very glad to be a virtual student of dr hans of underclass i learned a lot from him without even meeting him yet thank you for that take that as a comment uh tom daley are there any useful discussion forums using gis and or python in water hydrology hydraulic applications well i would say ice women australian water school are going to be doing a lot more of this in 2020 keep your eye on the website what do you think craig yeah well let me just uh uh turn this into a conglomerate of a few of these questions that have come up um hans um lots of people want to know they saw your screens come up um how are the attendees gonna be able to get those links and click on them how how are we going to be able to access those um and and i guess uh in short to answer that question there are linkedin groups um there are facebook groups there are plenty of discussion forums including some of the links that that hans has put up there but uh how do people get how are the attendees going to be able to get to all those uh those links sounds well the easiest thing is uh just go to gis opencourseware.org i'm sure we can post it somewhere i can put it in the chat if it's not already mentioned there that'd be great yep sounds good um where did where should we head next we've got chris chris ashwin on the on the line to speak um on on screen we could go there or go to mustafa's um line let's go to chris escher and he's right there on screen now chris we'll hand over to you now turn your mic on we're ready to roll no my name is chris no word from chris no no he's just talking quietly um we we can hear you chris but um talk a little louder oh okay sure that's it that's it where are you from chris can you hear me donna good good go far away yeah all right um i've been working on something for my final year project trying to do um a simulation by 3d flood uh terrain i don't know if you can hear me guys we can very clear yeah so um what i want to do is there's a lot of flood issues in in ghana that uh i'm trying to come up with a project where we could simulate a rainfall event on a terrain model yeah so when i saw the webinar i'm like okay i'm going to follow and then see the simulation and one of the guys i can't remember the name did a a presentation using a crayfish the m doll and a huge where he did a little that's dropped out all right we'll have to leave it i'm sorry about that uh where do you want to head to your next craig jason cooper's question or a quick one from dwight baldwin could you mention that pipe network extension again move it that'll be back to sauber uh q what yeah it's q water but q w 80 q what okay dwight that's done thank you for that uh beauty where to next do you think well i think um again for those of you who are asking questions and especially sorry if that that connection went out um send that question in writing we don't want to leave anybody hanging um absolutely i've got a few of these uh going on here one question that came up that i'm going to throw out there for all the attendees especially those from australia we looked on the map and saw that there are some from australia quite a few um somebody asked is the australian government helping out with funding i'm not sure if you're aware of any uh australian government uh support for qgis you know let us know and we'll continue to distribute that out um i don't know if hans or sauber are aware of any uh support from australia since this is the australian water school i'm not aware of any uh generally yeah some of the active most active qgs developers are from australia actually the most active developer and also as i said organizations from australia have been funding some of these features which have been showing you so they are definitely behind qgis and they would like it to be more widely used how about the australian government though that was the the question was about the government uh government they had some investment but uh for example for crayfish animation but uh government funding is a bit difficult the procurement process so private organizations they have got a bit of a better chance of funding those features great pick a question yeah by hans and saber feel free to jump in here um i'm going to be answering a couple of the specific ones about hydraulics that aren't necessarily related to qgis but again one of the main questions i guess compiling about 20 of the ones that have been answered is on the compatibility between uh the software now we need to distinguish between the animations and the meshing and just the shape files and the terrains once you have a raster grid digital elevation model you can use it in any software it doesn't matter global map or map info or esri products or qgis razmapper any raster grid digital elevation model as long as you're projected correctly you're going to be able to interchange those between them freely and open and potentially edit them as well same with raster or vector based shape files the incompatibility is what we're talking about is mainly on the uh the meshing and the animations and some of the more advanced tools and so hans or sauber um in any more comments again this this is probably 10 to 20 questions that have already come up on compatibility between versions or between software platforms if you wanted to add anything on that well just want to say that about amdahl is an open source uh tool for similar to gdaw as cyber has explained and we can really only use those two tools if the the model developers with proprietary tools open up their uh descriptions of their their file formats so there's limitations on the side of the providers and of course there's a lot of reverse engineering going on even even for the shapefile that has been done and another question that keeps coming up frequently is the hdf files that hec-ras uses the the hdf with the the hierarchical data format which the hdf view any any discussion or comments on compatibility with hdf uh and alfred's uh most of uh the 2d version of the hdf hdf is a file container is not a file format so it depends on what data it contains if it contains 2d model output you can directly open it in qgis and that's what i've been demonstrating in your map so on my screen yep well there's chris eshen's question then now i'm working on a flood simulation using a printed 3d terrain model would like suggestions on which tools and softwares to help with this project maybe we're going to have to make this one of our last questions we're about two minutes two minutes before the one that's very interesting now being able to use uh 3d printing and and scale make scale models um that's that's that's an awesome uh yeah i'm not sure it's not necessarily related necessary specifically to qgis but um it's it's a field that uh you know we may want to look into and also um you know stay tuned for a 3d modeling uh webinar coming up uh that you you may be interested in a lot of the uh physical models uh are trying to simulate 3d processes that hec-ras or other 1d and 2d software i can't can't uh can't handle and so um that will be doing that early next year as well looking at a couple of the other questions here uh i you know i think hans and uh and sauber i'm going to keep answering some of the hydraulic related questions and i'll i'll i'll leave it to you guys to see if there's anything else you wanted to answer live um otherwise we'll turn it back to you for the housekeeping because we're uh pretty much out of time phillips questions is pretty i'm sorry jason has a long question there maybe monitor answer that no yeah i have to answer that one offline okay i'll leave that to you then uh phillip says is is it possible to model fate and transport of pathogens using a catchment model coupled with a lake model in qgis who's going to take that on that that's heavy duty uh hydrodynamic modeling there you could use qgis for some of that but um you'd need you'd need some proprietary software you you're not going to get uh many free tools that are going to do that uh in the in a proper way any any comments hans or sober yeah as you mentioned qgis is mainly for pre-processing or post-processing all the black boxes which do all the magic here it should be done outside qgis otherwise it becomes a bloated software look you know we're gonna have to draw this to a close i i'm appreciating all your questions everyone and we are all loving this discussion but we could go for a lot longer what we're going to do is run a short course in 2020 stand by the chat line you'll see the registration of interest for that um that course and there it is at the bottom of that screen right now uh register interest uh the the link will be in the chat line thanks christy um but we have had a fantastic time today uh with all three silver cray hunts uh thanks for your participation feedback survey will come on automatically you don't for do anything it'll just whip up spend a minute and dig some boxes that'll be really good we're going to email the link to this recording so you can share it with your colleagues free webinars coming up there in the next few weeks and this happens every month we're uh inundated uh and some online courses there you can see we're looking forward to seeing you again uh next time you're looking for online training professional development um go to the australian water school the ice warm uh website and you will see more than you can handle i'm dead certain any last comments from hans saba frey all good thank it's been a great time thanks very much everyone thank you for joining each one of you uh wherever you are in the world and uh for hans and salva at midnight and cray at some unearthly hour of the morning they're in perth um we've had a great time i'm going to say goodbye for now thanks so much for joining everyone see you next time thank you bye subscribe to this youtube channel by clicking the subscription button for future webinars and online short courses please visit our website at australianwaterschool.com

Channel: Australian Water School

Views: 13,472

Keywords: QGIS, HEC-RAS, Water Modelling, Water Resources Management, QGIS Modelling, Surface Water Modelling, HEC RAS, HECRAS

Id: grK5iTkwWOU

Length: 58min 16sec (3496 seconds)

Published: Tue Dec 10 2019