Helen, I also have considerable experience trying to anchor ibuttons in stream beds. I have found that ibuttons are fairly durable, although there is definitely a failure rate, which seems to increase with the depth they are submerged.
For measuring surface stream temps I have attached them to the outside of 20cm long wooden dowels, which works in general, but some have been lost or buried during exceptionally large storms where large sediment movement occurs. I have also placed them deeper in the bed to measure hyporheic temperatures by inserting them into pvc that has perforations to allow water to access the ibuttons at various depth intervals. I have never lost any of these ibuttons via storm damage, although I have had to replace the pvc once in a while after a storm. However, as I mentioned before, the higher water pressure seems to cause them to fail more often in this setting. I got some of the pvc deployment details from Johnson et al. 2005. Ground Water Monitoring and Remediation. 25(4):68-74. Finally, I have considerable experience hammering piezometers into cobble stream beds, and it is difficult but possible. I use a nylon-tipped steel pipe driver to create a hole, and then pound the pvc piezometer into the hole. Takes a lot of persistence and flexibility. This method was borrowed from Maury Valett at Virginia Tech. Good luck, and feel free to email me at [EMAIL PROTECTED] for additional details. Erich Hester http://www.unc.edu/~ethester/ On Thu, 19 Jul 2007 11:38:22 -0400, Helen Neville <[EMAIL PROTECTED]> wrote: >Hello, > >I'm wondering if anyone has successfully put thermographs in stream beds to >record stream temperatures throughout the year, and if so what method of >securing them you used. > >We have been securing small Tidbit readers by bolting them in to short >pieces of metal pipe and securing those with steel cable either to trees or >large boulders up on the stream bank. This method is semi-successful, but >occasionally when streams blow-out we loose the readers. I think my >predecessors have tried various iterations of staking them with rebar in >the stream bed, but that didn't work so well and the cable set up seems to >be better. > >Perhaps it's just the way it goes to loose some every year, but any >suggestions would be much appreciated!! Thanks, Helen > >Helen Neville, Ph.D. >Research Scientist >Trout Unlimited >1020 Main St., Suite 440 >Boise, ID 83702 >[EMAIL PROTECTED] >Phone: 208-938-1110 x13 >Fax: 208-344-0768 >Cell: 775-813-0269 >=========================================================================
