Saturday, November 28, 2009

Heavier Rainstorms Ahead in the Future

Heavier Rainstorms Ahead Due To Global Climate Change, Study Predicts
ScienceDaily (Sep. 27, 2009) — Heavier rainstorms lie in our future. That's the clear conclusion of a new MIT and Caltech study on the impact that global climate change will have on precipitation patterns.

But the increase in extreme downpours is not uniformly spread around the world, the analysis shows. While the pattern is clear and consistent outside of the tropics, climate models give conflicting results within the tropics and more research will be needed to determine the likely outcomes in tropical regions.
Overall, previous studies have shown that average annual precipitation will increase in both the deep tropics and in temperate zones, but will decrease in the subtropics. However, it's important to know how the frequency and magnitude of extreme precipitation events will be affected, as these heavy downpours can lead to increased flooding and soil erosion.
It is the frequency of these extreme events that was the subject of this new research, which will appear online in theProceedings of the National Academy of Sciences during the week of Aug. 17. The report was written by Paul O'Gorman, assistant professor in the Department of Earth, Atmospheric and Planetary Sciences at MIT, and Tapio Schneider, professor of environmental science and engineering at Caltech.
Model simulations used in the study suggest that precipitation in extreme events will go up by about 6 percent for every one degree Celsius increase in temperature. Separate projections published earlier this year by MIT's Joint Program on the Science and Policy of Global Change indicate that without rapid and massive policy changes, there is a median probability of global surface warming of 5.2 degrees Celsius by 2100, with a 90 percent probability range of 3.5 to 7.4 degrees.
Specialists in the field called the new report by O'Gorman and Schneider a significant advance. Richard Allan, a senior research fellow at the Environmental Systems Science Centre at Reading University in Britain, says, "O'Gorman's analysis is an important step in understanding the physical basis for future increases in the most intense rainfall projected by climate models." He adds, however, that "more work is required in reconciling these simulations with observed changes in extreme rainfall events." The basic underlying reason for the projected increase in precipitation is that warmer air can hold more water vapor. So as the climate heats up, "there will be more vapor in the atmosphere, which will lead to an increase in precipitation extremes," O'Gorman says.
However, contrary to what might be expected, extremes events do not increase at the same rate as the moisture capacity of the atmosphere. The extremes do go up, but not by as much as the total water vapor, he says. That is because water condenses out as rising air cools, but the rate of cooling for the rising air is less in a warmer climate, and this moderates the increase in precipitation, he says.
The reason the climate models are less consistent about what will happen to precipitation extremes in the tropics, O'Gorman explains, is that typical weather systems there fall below the size limitations of the models. While high and low pressure areas in temperate zones may span 1,000 kilometers, typical storm circulations in the tropics are too small for models to account for directly. To address that problem, O'Gorman and others are trying to run much smaller-scale, higher-resolution models for tropical areas.
Massachusetts Institute of Technology (2009, September 27). Heavier Rainstorms Ahead Due To Global Climate Change, Study Predicts.ScienceDaily. Retrieved September 27, 2009, from http://www.sciencedaily.com/releases/2009/08/090817190638.htm

InfoSWMM and H2OMAP SWMM Version 8.5

MWH Soft Releases InfoSWMM and H2OMAP SWMM Version 8.5,
Leveraging the Latest EPA SWMM5 Functionality

Newest Iteration of Industry-Leading Geospatial Urban Drainage Modeling and Design Software
Delivers Expanded Engineering Simulation Value

Broomfield, Colorado USA, November 11, 2009 — MWH Soft, the leading global provider of environmental and water resources applications software, today announced the immediate release of Generation V8.5 of H2OMAP SWMM and InfoSWMM for ArcGIS (ESRI, Redlands, CA). The new version adds powerful features and leverages engine enhancements included in the latest release of EPA SWMM5 (5.0.017). It also improves the breadth and performance by extending MWH Soft tradition of including new enhancements specifically requested by customers. Version 8.5 marks a significant evolution of the company’s SWMM-based urban drainage modeling and design products, which continue to be top choices for the effective evaluation, design, management, rehabilitation and operation of wastewater and stormwater collection systems.
Underlining MWH Soft’s leadership in the wastewater industry, InfoSWMM and H2OMAP SWMM reflect the company’s ongoing commitment to delivering pioneering technology that raises the bar for urban drainage network modeling and simulation, helping to shape the future of this critical sector. The full-featured InfoSWMM urban drainage network analysis and design program is the only urban drainage modeling solution certified by the National Association of GIS-Centric Software (www.nagcs.com). It addresses all operations of a typical sewer system — from analysis and design to management functions such as water quality assessment, pollution prediction, sediment transport, urban flooding, real-time control and record keeping — in a single, fully integrated geoengineering environment whose powerful hydraulic computational engine is endorsed by the USEPA and certified by FEMA.

SWMM 5.0.018

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Build 5.0.018 (11/18/09)
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Engine Updates

1. Reporting of the total infiltration + evaporation loss for each
Storage Unit (as a percent of total inflow to the unit) was added
to the Storage Volume Summary table in the Status Report. See
objects.h, node.c, stats.c, and statsrpt.c.

2. Double counting the final stored volume when finding the nodes with
the highest mass balance errors has been eliminated. See stats.c.

3. A warning message was added for when a Rain Gage's recording
interval is less than the smallest time interval appearing in its
associated rainfall time series. (An error message is issued if
the recording interval is greater than the smallest time series
interval.) See gage.c and text.h.

4. Hot Start interface files now contain the final state of each
subcatchment's groundwater zone in addition to the node and
link information they have always had. See routing.c.

5. To avoid confusion, the actual conduit slope is now listed in the
Link Summary table of the Status Report rather than the adjusted
slope that results from any conduit lengthening. See link.c and
dynwave.c.

6. The Status Report now displays only those summary tables for
which results have been obtained (e.g., if the Flow Routing
option is turned off, then no node or link tables are displayed).
See massbal.c and statsrpt.c.

7. Some code re-factoring was done to place rain gage validation
and initialization in separate functions. See project.c, gage.c,
and funcs.h.

8. The engine version number was updated to 50018 (this update had
been overlooked since release 5.0.010). See consts.h.

GUI Updates

1. A bug that prevented Status Report files from being deleted from
a users TEMP folder when they were no longer in use was corrected.
Users should check their TEMP folders (usually in
c:\Documents and Settings\\Local Settings\Temp)
for old files that begin with "swm". These can safely be deleted.

2. The project input file created for use by SWMM's Add-On Tools now
contains all project data, including map coordinates and element
tags.

InfoSWMM Version Numbers and the version of Arc Map they use and which EPA SWMM5 Engine is used for Each InfoSWMM Version

 InfoSWMM Version Numbers  InfoSWMM Version 14.7  Update 3 for Arc Map 10 to 10.8 and Windows 7/8/8.1/10 - EPA SWMM 5.1.014   4/12/2020   ...