## Posts

Showing posts from January, 2010

### Vertical Migration of SWMM 5 Calibration Files

Note:It is often important to compare the results for your link flows, node heads and system variables between SWMM 5 versions to help you calibrate the new version based on the old version results. If you run a SWMM 5 model in an older version, save the .rpt and .out file and then open up the SWMM 5 input file in a newer version of SWMM 5 you should see a active graph symbol. The active symbol means that you can plot the results of the old model in the newer SWMM 5 GUI.

For example, you can plot one of the system variables and then save ALL of the system variables to either a clipboard or a system calibration file. You can then use the Calibration dialog of SWMM 5 to compare the older results with the simulation results of a new version of SWMM 5.

### Water Analogies for Divergence, Curl and Gradient

Comment: A really nice water analogy for the field properties Divergence, Curl and Gradient from the Blog Starts With a Bang

....it's pretty mathematically intensive, but what's missing from most textbooks and E&M courses are physical explanations of what the mathematics means. For instance, I've started teaching about fields, and pretty much every textbook out there goes on and on about the properties of fields. They say you can do three things to fields, take the gradient, divergence, orcurl of them. (Are you asleep yet? I'm sorry!) What do these things mean? An easy way to picture it is in terms of water. If you placed a drop of water anywhere on, say,Earth, the magnitude and direction of how it rolls down is the gradient of the Earth's elevation. If you let that drop of water flow, as it goes downhill, it can either spread out or converge to a narrower stream. When we quantify that, that's what the divergence of the field is. And finally, when that water is …

### Water Hits and Sticks: Findings Challenge a Century of Assumptions About Soil Hydrology

From Science Daily

ScienceDaily (Jan. 23, 2010) — Researchers have discovered that some of the most fundamental assumptions about how water moves through soil in a seasonally dry climate such as the Pacific Northwest are incorrect -- and that a century of research based on those assumptions will have to be reconsidered.

A new study by scientists from Oregon State University and the Environmental Protection Agency showed -- much to the surprise of the researchers -- that soil clings tenaciously to the first precipitation after a dry summer, and holds it so tightly that it almost never mixes with other water.
The finding is so significant, researchers said, that they aren't even sure yet what it may mean. But it could affect our understanding of how pollutants move through soils, how nutrients get transported from soils to streams, how streams function and even how vegetation might respond to climate change.
The research was just published online in Nature Geoscience, a professional jou…

### Runoff Example Files for SWMM 4

These are 48 Runoff Example Files that I created based on PC-SWMM 3, SWMM 3 and new SWMM 4 features at UF between 1985 and 1981..

These files will work with any SWMM 4 version. If you look at page http://www.swmm2000.com/SWMM4/swmm-3-4-dos-engines

we have a variety of SWMM 3 and SWMM 4 engine.

The File Runoff45.DOC is the text documentation for the SWMM 4 Runoff File.