Archive for October, 2009

Here’s a nice blog entry about river meandering and some of the historic recontructions and flume experiments that have been conducted to look at meanders.

How to build a meandering river in your basement : Highly Allochthonous.


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Peak flows can be derived a number of different ways. FEMA Flood Insurance Studies have regulatory power and are typically accepted as the standard, regardless of how much time (and subsequent watershed changes) might have passed since the report was written. The engineering methods in an FIS vary; sometimes they use a rainfall-runoff model, sometimes they use a gage or are scaled from a gage and occasionally they use a regional regression.
Flood frequency gage analysis can be done fairly rapidly using USGS’s PKFQWin. Once peak flows are downloaded and saved from a given gage site, this become the input file in the software. A few more clicks of the mouse and tabular and graphical output are generated. Users should put some thought into what skew option to use, and whether or not to considered regulated peaks. Finally, regional regressions can be obtained by a USGS web service called Streamstats. This service is not available in all states and in Massachusetts the output is based on a low flow analysis. The MA Streamstats site does provide its own gage analysis for select gages. The table below provides a summary of these outputs at the Parker River gage near Byfield, MA (gage # 01101000).

Peak flow analysis_summary.pdf

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I’ve been impressed with MIT’s opencourseware initiative.  However, when it comes to specific instructions on how to actually complete an analysis using industry standard software (e.g. ESRI’s ArcGIS), this is one of the more impressive how-to compilations I’ve run across from academia.


The best place to keep ArcHydro, GeoRAS and GeoHMS current is at this ftp site:

ftp.esri.com / username: riverhydraulics / password: river.1114

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Here’s a link to the 2008 William Morris Davis Lecture given by Dorothy Merrits at Boston College. I found it to be a fascinating lecture, but unfortunately, the camera is not focused on the slides, so it’s a bit difficult to fully grasp the content.


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