Interactively Derive Streams and Catchments in QGIS Using the Graphical Modeller

Подписаться 28 тыс.

Просмотров 5 тыс.

50% 1

In this video we'll create a graphical model that derives the streams and the catchment of a user-defined extent and outlet point. The model automatically downloads the SRTM 1 Arc Second DEM from the OpenTopography DEM Downloader plugin and uses the PCRaster Tools plugin for the hydrological analysis.
The model is available in the PCRaster Tool resource sharing repository: github.com/jvdkwast/qgisrepos...
From this QGIS Resource Sharing repository you can also install a script that does the same, but a bit more efficiently: github.com/jvdkwast/qgisrepos...
QGIS version: 3.28 Firenze
Plugins: PCRaster Tools plugin, OpenTopography DEM Downloader plugin
Open data: SRTM
0:00 Introduction
0:35 Create a graphical model that saves a clicked point in a vector layer
2:00 Create a model for stream delineation
10:39 Add the model for catchment delineation
16:29 Add a help text
16:55 Use the model to derive streams and catchment of a clicked point
#QGIS #QGISHydro

Опубликовано:

1 авг 2024

Ссылка:

Скачать:

Готовим ссылку...

Добавить в:

Мой плейлист

Посмотреть позже

Комментарии : 26

@samirkumarsingh2960 Год назад

Hes always imparting knowledge without keeping things to himself...so good a GURU G he is.

@mandata143 Год назад

Hello Dr. I am from PH, a GIS practitioner. Thank you so much for giving us tutorials!

@evanslion3548 11 месяцев назад

Thank you very much for this.

@Tylhuynh06 11 месяцев назад

This guy is a GOD

@gisworld-tech Год назад

great thanks for sharing

@rkreddymrsv4958 Год назад

Good job sir

@eric_eagle 11 месяцев назад

This is really cool. I use stream order as one input to a larger overland mobility model. I run it in a proprietary GIS right now but this makes me really interested to implement it in QGIS to compare performance. One thing QGIS lacked though the last time I tried, was Natural Breaks classification for Raster output.

@HansvanderKwast 11 месяцев назад

Thanks. Natural Breaks is still not available in QGIS.

@NIXONGR123 Год назад

💪💪💪💪💪💪

@robaitken4809 Год назад

Hans, as always your videos are truly amazing, thanks for taking the time to share! Is there an input or algorithm that could be used to select a DEM from a QGIS project or folder on your computer instead of from the Open Topography DEM Downloader?

@HansvanderKwast Год назад

Sure. When you edit the graphical model, just replace the OpenTopography part with a Raster layer input that links to warp. The rest is the same.

@justinecarey9692 7 месяцев назад

Hi Hans, I have installed PCRaster using Conda on my MacOS (as per your other tutorial), however now when I try to run this model, I get an error that the grass7 r.thin algorithm is not available. When I check the plugins, GRASS GIS Processing Provider appears to be installed already, I'm not able to find grass7. Do you know a way to get both PCRaster and grass7 working successfully on a Mac? I have a series of approximately 50 sub-catchment areas I would like to calculate, so the tool you share in this tutorial would be really helpful. Thanks in advance.

@HansvanderKwast 7 месяцев назад

Hi! GRASS doesn't work in conda (this is not specific to Mac), so you have to do that part in your regular QGIS installation on a Mac.

@evanslion3548 Год назад

Thanks for the tutorial. I seem to have a problem installing the PC Raster Tools plugin. I get the following error "PCRaster Tools Plugin: PCRaster is not installed -- algorithms will not be available".

@evanslion3548 Год назад

I am using the released version of QGIS 3.32.1

@HansvanderKwast Год назад

The PCRaster Tools plugin is a so-called Processing Provider plugin (like GRASS, SAGA, WhiteboxTools). Therefore, you need to install the software separately, before you can use the plugin. Here's the link to the documentation with installation instructions: jvdkwast.github.io/qgis-processing-pcraster/ More info about Processing Provider plugins in QGIS: ru-vid.com9fWQZqPjPVk?feature=share

@evanslion3548 Год назад

@@HansvanderKwast Very helpful. Thanks

@calvinquigley6000 5 месяцев назад

Hi Hans! This is really impressive. I tried to follow along, but when I run the model I get an error from GDAL's reproject(warp) "Attempt to create 0x0 dataset is illegal", which then causes convert_to_pcraster to fail with: src_ds = gdal.Open(input_raster.dataProvider().dataSourceUri()) AttributeError: 'NoneType' object has no attribute 'dataProvider' any idea what could be causing that? Thanks!

@HansvanderKwast 5 месяцев назад

It looks like it didn't download the DEM. Check the results of the steps to see where it goes wrong.

@315royce Год назад

Thank you for this video , this will help my workflow faster. I have a question sir, there is this 'Error encountered while running Calculate flow Direction Execution failed after 14.97 seconds.'' How can i solve this one?

@HansvanderKwast Год назад

Probably you haven't installed the PCRaster Tools plugin correctly. It could also be that the area is too large or that it's not able to save the temporary file. Test the procedure manually, step by step in that case to see where the problem starts.

@315royce Год назад

@@HansvanderKwast Thank you very much sir. Will surely do your suggestion!