Chapter 20
Infiltration measurement and sampling
Outline:
- Example field studies of infiltration measurement Green-Ampt equation for infiltration
- Empirical infiltration functions
- Kostiakov function Modified Kostiakov
- Philip's equation
- Here is the Excel file infiltration.xls demonstrating the different infiltration equations.
Textbook reading:
- Chapter 7: pages 113-118.
Other reading:
- Bedient, P.B. and Huber, W.C. 1992. Hydrology and Floodplain Analysis, 2nd Edition. Addison-Wesley Publishing Co., Reading, MA. PAGES 51-59.download here
- Earth Systems Solutions. Tensiometer Users Guide. Santa Barbara, CA.download here
Related web links:
- none.
Video Podcast: Infiltration
This 58-minute presentation describes how to measure cumulative infiltration and infiltration rate through time.
- 640 x 480 (480p) format that balances speed and quality. (841 MB file)
- 1920 x 1280 (HD) format that provides larges size and best quality. (5.2 GB file)
Errata
In the video podcast the infiltration spreadsheets for Kostiakov and modified Kostiakov functions were shown to be set up with cumulative infiltration as a function of "end time". That was correct and the spreadsheet linked to this web page is correct. In the video podcast, I confused myself and thought the functions for cumulative infiltration should be switched to the midpoint time. That was wrong and the original spreadsheet was correct. The reason is that cumulative infiltration is the total amount through to the end time in each row, so it is not assigned to the midpoint time. Only infiltration rate is averaged through the time interval for each reading, so it is assigned to the midpoint time. I could re-do the video podcast, but I am of the belief that it can help to do things wrong and learn from one's mistakes- freedom to fail and learn. That is why I am providing this errata and giving you the chance to think through my failure.
