Hydrology in ArcGIS Pro, Lab Exercise 1: Calculating Areas from Raster Datasets

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Here we see how to use the cell size and the linear unit of projected rasters to calculate the area within a raster that meets some criteria. We'll see how to do this using the standard Windows Calculator, and by adding an attribute field to your raster attribute table containing the area values. This can be a much faster and simpler method than converting the rasters to polygons and then calculating the area of the polygons, but it does have the downside that you can't calculate the more accurate geodesic areas. However, if your raster is in a good projection, such as any equal-area projection, then any projection distortion errors are minimal.
Basic Hydrologic Analysis in ArcGIS Pro Lecture: • Basic Hydrologic Analy...
Lab Exercises:
Lab 1: Calculating Areas from Raster Datasets; • Hydrology in ArcGIS Pr...
Lab 2: Problems when creating Watersheds without filling the DEM; • Hydrology in ArcGIS Pr...
Lab 3: Filling Sinks in a DEM; • Hydrology in ArcGIS Pr...
Lab 4: Calculating an Accurate Flow Direction Raster; • Hydrology in ArcGIS Pr...
Lab 5: Generating an Accurate Watershed; • Hydrology in ArcGIS Pr...
Lab 6: Creating a Flow Accumulation Raster; • Hydrology in ArcGIS Pr...
Lab 7: Generating a Stream Network using Strahler Stream Orders; • Hydrology in ArcGIS Pr...
Lab 8: Aspect Statistics within Watershed; • Hydrology in ArcGIS Pr...
Lab 9: Slope Statistics within Watershed; • Hydrology in ArcGIS Pr...
Lab 10: The Topographic Wetness Index (TWI); • Hydrology in ArcGIS Pr...
Lab 11: Finding the Shortest Path Through the Stream Network; • Hydrology in ArcGIS Pr...
Extra Materials:
Word Document with walk-throughs of lab exercises: docs.google.com/document/d/13...
Data for Lab Exercises: drive.google.com/file/d/1i07m...
Manuscripts discussing TWI: drive.google.com/file/d/1W4Ty...

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13 ноя 2022

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Комментарии : 9

@aalmoadi 3 месяца назад

thank you very much, you are amazing

@jennessenterprisesadventur5081 3 месяца назад

Thanks for the kind words Abdulrhman! This was a good start to the day!

@choi105 Год назад

Thank you so much. Prof.

@jennessenterprisesadventur5081 Год назад

Glad it was useful! Thank you for letting me know.

@cissyamparolavadenz1059 8 месяцев назад

thank you very much for your videos! I would like to ask how to manage the raster projection if the raster of our study area is in geographic coordinates? or is there any available web where we can obtain projected rasters in UTM from other places of the world, besides the US?

@jennessenterprisesadventur5081 8 месяцев назад

Thanks Cissy! I much appreciate the feedback! For global DEMs, I've used the SRTM (Shuttle Radar Topography Mission) and ASTER (Advanced Spaceborne Thermal Emission Reflectometer) data (both of which you should be able to find at earthexplorer.usgs.gov/). I had some issues with the ASTER data, though, because it appeared to map canopy height instead of ground height. This wasn't a problem when I just wanted elevations of locations, but it made it difficult to get accurate slope, curvature and hydrological data. I've head good things about the JAXA ALOS (Japan Aerospace Exploration Agency [JAXA] Advanced Land Observing Satellite [ALOS]) data (see www.eorc.jaxa.jp/ALOS/en/dataset/aw3d_e.htm), but I've never tried it. I've also downloaded lots of data in the past from UN agencies like FAO, but I don't think I've downloaded any DEMs from them. I've also occasionally found data by looking up the local administrative websites (like county, state or municipality websites) and searching for GIS data. In general, though, it might be difficult to find data that aren't in geographic coordinates. If you just can't find any, and if the tools you use to process them don't offer geodesic options, then you will just have to project them. If you do, make sure you use bilinear interpolation when you project! It'll modify your topography a little, sort of like smoothing it with sandpaper, but probably won't do any critical damage. Hope this helps! Thanks again for the kind words. Take care - Jeff

@shazrielimran430 7 месяцев назад

May I know what version is your ArcGIS Pro?

@jennessenterprisesadventur5081 7 месяцев назад

Hmm. Good question. I should probably add that info to future videos, shouldn't I? This was probably done with ArcGIS Pro 3.1.0 or 3.1.1. Possibly 3.1.2. It wouldn't have been 3.0 or earlier. Hope this helps! Take care - Jeff

@shazrielimran430 7 месяцев назад

@@jennessenterprisesadventur5081 Thanks. Because I tried using your data and it works with my 3.0.1 version but not with data that I got from my colleague (which is below version 3.0)