Average Residence time in InfoSWMM and H2OMAP SWMM

Subject:  Average Residence time in InfoSWMM and H2OMAP SWMM

Average Residence time in InfoSWMM and H2OMAP SWMM by dickinsonre Subject:  Average Residence time in InfoSWMM and H2OMAP SWMM Here is one way to estimate the residence time: 1.       Plot the System Outflow and Storage in the InfoSWMM Report Manager 2.       Click on the Report Button and copy the Outflow and Storage Time Series 3.       Paste to  Excel 4.       Calculate the Residence time as Storage / Outflow and Graph 5.       You will have an understanding of the residence time in your network 6.       If you have a dry weather flow then a hot start file will give a better estimate at the start of the simulation  via Blogger http://www.swmm5.net/2013/08/average-residence-time-in-infoswmm-and.html

Innovyze President Receives ACOPNE’s Highest Honor

Dr. Paul F. Boulos Named Distinguished Diplomate in Navigation Engineering by the ASCE Academy of Coastal, Ocean, Port & Navigation Engineers 

Innovyze President Receives ACOPNE’s Highest Honor

Broomfield, Colorado USA, April 24, 2012 — The Board of Trustees of the Academy of Coastal, Ocean, Port & Navigation Engineers (ACOPNE) has awarded Innovyze President Dr. Paul F. Boulos Distinguished Diplomate status in Navigation Engineering (Dist.D.NE), the academy’s highest honor. As a recipient of this award, Dr. Boulos joins an elite group of 23 diplomates worldwide with this distinction. Dr. Boulos will be presented this signal award at a special induction ceremony and reception to be held during the Dredging 2012 conference in San Diego, California, October 22-25. ACOPNE is an affiliate of the American Society of Civil Engineers (ASCE). Dredging 2012 is a four-day technical specialty conference organized by PIANC USA and the Coasts, Oceans, Ports and Rivers Institute of American Society of Civil Engineers (COPRI ASCE).

Dr. Boulos is one of the world’s foremost experts on water resources and navigation engineering. He has won numerous industry honors, including notable technical awards from ASCE, the American Water Works Association and the U.S. Environmental Protection Agency, and was inducted into the University of Kentucky College of Engineering Hall of Distinction, the most prestigious honor given by the university to its alumni. His publications include nine authoritative books and more than 100 scholarly papers. He is a Fellow of the American Society of Civil Engineers (F.ASCE), a Board Certified Environmental Engineer (by eminence) of the American Academy of Environmental Engineers (BCEEM), and an Honorary Diplomate of Water Resources Engineering (Hon.D.WRE) of the American Academy of Water Resources Engineers (AAWRE), the academy’s highest honor. He graduated with a Bachelor of Science degree in General Science from the Lebanese American University (Beirut, Lebanon) and was named the university’s 2008 Alumnus of the Year for his extraordinary professional achievement. Dr. Boulos also received a Doctorate, Master of Science and Bachelor of Science with distinction in Civil Engineering from the University of Kentucky in Lexington and has completed the Advanced Management Program at Harvard Business School.
“I am deeply humbled and honored to be selected for this distinguished award,” said Boulos. “I am so proud to be a part of this noble and great profession and to be able to contribute to its advancement. It’s truly a privilege to receive such special recognition for doing something I deeply love and enjoy — especially when it comes from the men and women I most admire.”
Diplomate status credential recognizes an advanced expertise in the practice of Coastal, Ocean, Port & Navigation Engineering (COPNE). Navigation engineering involves the life cycle planning, design, construction, operation and life maintenance of safe, secure, reliable, efficient and environmentally sustainable navigable waterways (channels, structures and support systems) used to move people and goods by waterborne vessels. Distinguished Diplomate status, ACOPNE’s highest honor, is awarded exclusively to those who have made significant contributions to the COPNE profession. To date, only 23 engineers and practitioners worldwide (eight in navigation engineering) have earned this distinction, a tribute to their exceptional technical and professional leadership within the COPNE community.
“We are proud to honor Dr. Boulos for his eminence, commitment and exceptional contributions to the profession,” said Michael A. Ports, PE, PH, D.WRE, D.NE, BCEE, Principal of Ports Engineering in Jacksonville, Florida, and President of ACOPNE. “He has distinguished himself professionally amongst his peers and demonstrates the characteristics of a role model to his fellow engineers and to the members of the community. We thank and congratulate him for his lifetime of achievements, tireless efforts, and advocacy for the advancement of research and best practices in navigation engineering.”
For more information on ACOPNE, visit www.acopne.org.
About Innovyze
            Innovyze is a leading global provider of wet infrastructure business analytics software solutions designed to meet the technological needs of water and wastewater utilities, government industries, and engineering organizations worldwide. Its clients include the majority of the largest UK, Australasian, East Asian and North American cities, foremost utilities on all five continents, and ENR top-rated design firms. With unparalleled expertise and offices in North America, Europe, and Asia Pacific, the Innovyze connected portfolio of best-in-class product lines empowers thousands of engineers to competitively plan, manage, design, protect, operate and sustain highly efficient and reliable infrastructure systems, and provides an enduring platform for customer success. For more information, call Innovyze at +1 626-568-6868, or visit www.innovyze.com.

Example Dual Drainage SWMM 5 model

Topic:  Example Dual Drainage SWMM 5 model

Example Dual Drainage SWMM 5 model by dickinsonre

 Example Dual Drainage SWMM 5 model

via Blogger http://www.swmm5.net/2013/08/example-dual-drainage-swmm-5-model.html

Sam Shamsi and swmm-online-com

Topic:  Sam Shamsi and swmm-online-com

Sam as an interesting blog or web page with other GIS and SWMM links including his well  known annual Top 10 list about various Stormwater modeling subjects.  The link is
http://sites.google.com/site/shamsigisapplications/3-my-web-sites/swmm-online-com

The Pump summary table of SWMM5.0.022 and the Percent Time off Columns

Subject:  The Pump summary table of SWMM5.0.022 and the Percent Time off Columns

The Pump summary table of SWMM5.0.022 and the Percent Time off Columns by dickinsonre Subject:  The Pump summary table of SWMM5.0.022 and the Percent Time off Columns The pump summary table at the end of the SWMM 5 report file has two columns for the time off the pump curve BUT the two columns are only informative if the pump is a type 4pump.  If the pump type is 1, 2 or 3 then the low column is always 0 and when the volume, depth or head is either below the lowest point in the point curve or above the highest point in the pump curve the pump summary table lists the time off either low or high in the High column. xMin is  the 1st point in the pump curve for either volume, depth, head or depth, respectively for pump1, pump2, pump3 and pump4 type pumps xMax is the last point in the pump curve for either volume, depth, head or depth, respectively for pump1, pump2, pump3 and pump4 type pumps via Blogger http://www.swmm5.net/2013/08/the-pump-summary-table-of-swmm50022-and.html

Dual Drainage in SWMM 5

Subject:  Dual Drainage in SWMM 5

The purpose of the Dual Drainage tool in InfoSWMM is to create a major or street drainage network on top of an existing pipe or what is called the minor network in  dual drainage.  The created major network has a node (sometimes called the inlet node) on top of the existing minor network node connected by two  OUTLET links.  One outlet link takes the flow from the street and  passes it to the minor network node, the second outlet link  takes the surcharged minor network flow and passes it to the major network or street – the direction of flow is important (Figure 1).  The general purpose of the Captured OUTLET is to  use a head or depth equation to separate the street incoming  flow into captured flow and bypass flow

Figure 1.  Dual Drainage in General

Figure 2.  How it looks in SWMM 5 with node, outlet and conduit elements.

Bloomberg: Heat Waves, Rains Probably Linked to Warming, Scientists Say

Heat Waves, Rains Probably Linked to Warming, Scientists Say

By Rudy Ruitenberg - Mar 26, 2012 6:23 AM ET

Heat waves and extreme rainfall in the past decade are probably linked to global warming, according to a study by scientists at the Potsdam Institute for Climate Impact Research.

“For some types of extreme, notably heat waves but also precipitation extremes, there is now strong evidence linking specific events or an increase in their number to the human influence on climate,” the scientists wrote in a study published in the journal Nature Climate Change.

The past decade included Europe’s hottest summer in at least 500 years in 2003, according to the scientists. 2010 brought western Russia’s hottest summer in centuries and record rain in Pakistan and Australia, they wrote. Japan and some U.S. states registered all-time-high rainfall last year, while the Yangtze River basin in China had a record drought.

Basic physics exercises suggest that warming of the atmosphere leads to more extremes, according to the institute. For example, warm air can hold more moisture that may fall as rain, the scientists wrote. Computer simulations confirm the relation between warming and record temperatures and rainfall, the study showed.

The recent high incidence of weather records is “no longer normal,” according to Dim Coumou, the lead author of the study.

To contact the reporter on this story: Rudy Ruitenberg in Paris at rruitenberg@bloomberg.net

To contact the editor responsible for this story: Claudia Carpenter atccarpenter2@bloomberg.net

How to Make a SWMM 5 Calibration File from InfoSWMM

Subject:  How to Make a SWMM 5 Calibration File from InfoSWMM

1^st Step:  Graph a Link  in InfoSWMM using the Date /Time Format

2^nd Step:  Click on the Report Button and copy the 1^st two columns of data

3^rd Step:  Save the  copied columns to a data file, replace the semi colon and add the name of the link  to the top of the data file as shown below

4^th Step:  Connect the created calibration data file t o the SWMM 5 Calibration Data Link Flow Rate

5^th Step:  Run the  Simulation and you should see two  graphs on the screen for the designated link

How to Make a SWMM 5 Calibration File from InfoSWMM by dickinsonre Subject:  How to Make a SWMM 5 Calibration File from InfoSWMM  1st Step:  Graph a Link  in InfoSWMM using the Date /Time Format 2nd Step:  Click on the Report Button and copy the 1st two columns of data 3rd Step:  Save the  copied columns to a data file, replace the semi colon and add the name of the link  to the top of the data file as shown below 4th Step:  Connect the created calibration data file t o the SWMM 5 Calibration Data Link Flow Rate 5th Step:  Run the  Simulation and you should see two  graphs on the screen for the designated link via Blogger http://www.swmm5.net/2013/08/how-to-make-swmm-5-calibration-file.html

Past in Monsoon Changes Linked to Major Shifts in Indian Civilizations

ScienceDaily (Mar. 16, 2012) — A fundamental shift in the Indian monsoon has occurred over the last few millennia, from a steady humid monsoon that favored lush vegetation to extended periods of drought, reports a new study led by researchers at the Woods Hole Oceanographic Institution (WHOI). The study has implications for our understanding of the monsoon’s response to climate change. The Indian peninsula sustains over a billion people, yet it lies at the same latitude as the Sahara Desert. Without a monsoon, most of India would be dry and uninhabitable. The ability to predict the timing and amount of the next year’s monsoon is vital, yet even our knowledge of the monsoon’s past variability remains incomplete.

One key to this understanding lies in the core monsoon zone (CMZ) – a region in the central part of India that is a very sensitive indicator of the monsoon throughout the India peninsula.

“If you know what’s happening there, you know more or less what’s happening in the rest of India,” said Camilo Ponton, a student in the MIT-WHOI Joint Program in Oceanography and lead author of the study recently published in Geophysical Research Lettersentitled "Holocene Aridification of India". “Our biggest problem has been a lack of evidence from this region to extend the short, existing records.”

The study was designed by WHOI geologist Liviu Giosan and geochemist Tim Eglinton, now at ETH in Zurich, and makes use of a sediment core collected by the National Gas Hydrate Program of India in 2006. Sailing around India aboard the drilling vessel JOIDES Resolution for several months, Giosan enlisted colleagues from India and US to help with the project.  Extracted from a “sweet spot” in the Bay of Bengal where the Godavari River drains the central Indian peninsula and over which monsoon winds carry most of the precipitation, the core has provided the basis for a 10,000-year reconstruction of climate in the Indian peninsula’s CMZ .

 “We are fortunate to have this core from close to the river mouth, where it accumulates sediment very fast,” said Ponton. “Every centimeter of sediment contains 10 to 20 years’ worth of information. So it gives us the advantage of high temporal resolution to address the problems.”

When put together, the research tells the story of growing aridity in India, enables valuable insights into the impact of the monsoon on past cultures, and points scientists toward a way to model future monsoons.

To assemble the 10,000-year record, the team looked to both what the land and the ocean could tell them.  Contained within the sediment core’s layers are microscopic compounds from the trees, grasses, and shrubs that lived in the region and remnants of plankton fossils from the ocean.

 “The geochemical analyses of the leaf waxes tell a simple story,” said Giosan.  “About 10,000 years ago to about 4500 ago, the Godavari River drained mostly terrain that had humidity-loving plants. Stepwise changes starting at around 4,000 years ago and again after 1,700 years ago changed the flora toward aridity-adapted plants. That tells us that central India – the core monsoon zone – became drier.”

Analyses of the plankton fossils support the story reconstructed from plant remains and reveal a record of unprecedented spikes and troughs in the Bay of Bengal’s salinity – becoming saltier during drought periods and fresher when water from the monsoon filled the river and rained into the Bay.  Similar drought periods have been documented in shorter records from tree rings and cave stalagmites within India lending further support to this interpretation.

With a picture emerging of changes in the ancient flora of India, Giosan tapped archaeobotanist Dorian Fuller’s interest.

“What the new paleo-climatic information makes clear is that the shift towards more arid conditions around 4,000 years ago corresponds to the time when agricultural populations expanded and settled village life began,” says Fuller of the Institute of Archaeology, University College London. “Arid-adapted food production is an old cultural tradition in the region, with cultivation of drought-tolerant millets and soil-restoring bean species. There may be lessons to learn here, as these drought-tolerant agricultural traditions have eroded over the past century, with shift towards more water and chemical intensive forms of modern agriculture.”

Together, the geological record and the archaeological evidence tell a story of the possible fate of India’s earliest civilizations. Cultural changes occurred across the Indian subcontinent as the climate became more arid after ~4,000 years. In the already dry Indus basin, the urban Harappan civilization failed to adapt to even harsher conditions and slowly collapsed. But aridity favored an increase in sophistication in the central and south India where tropical forest decreased in extent and people began to settle and do more agriculture. Human resourcefulness proved again crucial in the rapid proliferation of rain-collecting water tanks across the Indian peninsula, just as the long series of droughts settled in over the last 1,700 years.

What can this record tell us about future Indian monsoons? According to Ponton, “How the monsoon will behave in the future is highly controversial. Our research provides clues for modeling and that could help determine whether the monsoon will increase or decrease with global warming.”

The study found that the type of monsoon and its droughts are a function of the Northern Hemisphere’s incoming solar radiation – or “insolation.”  Every year, the band of heavy rain known as the Inter-Tropical Convergence Zone, or ITCZ, moves north over India.

“We found that when the Asian continent is least heated by the sun, the northward movement of the rain appears to hesitate between the Equator and Asia, bringing less rain to the north,” said Giosan. “The fact that long droughts have not occurred over the last 100 years or so, as humans started to heat up the planet, but did occur earlier, suggest that we changed the entire monsoon game, and may have inadvertently made it more stable!”

Story Source:

The above story is reprinted from materials provided byWoods Hole Oceanographic Institution.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

---

Journal Reference:

1. Camilo Ponton, Liviu Giosan, Tim I. Eglinton, Dorian Q. Fuller, Joel E. Johnson, Pushpendra Kumar, Tim S. Collett.Holocene aridification of India. Geophysical Research Letters, 2012; 39 (3) DOI: 10.1029/2011GL050722

Need to cite this story in your essay, paper, or report? Use one of the following formats:

 APA
 MLA

Woods Hole Oceanographic Institution (2012, March 16). Past in monsoon changes linked to major shifts in Indian civilizations. ScienceDaily. Retrieved March 17, 2012, from http://www.sciencedaily.com­/releases/2012/03/120316145802.htm

 

Map of the Indian peninsula, showing where the monsoon winds blow (white arrows) and how the salinity (white lines) is lower in Bay of Bengal due to monsoon rain over the Bay and rivers draining into the it. (The black arrow represents non-monsoon wind.) The study's sediment core (red dot) was extracted from a “sweet spot” in the Bay of Bengal where the Godavari River drains the central Indian peninsula and over which monsoon winds carry the most precipitation. (Credit: Courtesy of C. Ponton and L. Giosan) 

Importing and Comparing Simulation Results between InfoSWMM and SWMM 5

Subject:  Importing and Comparing Simulation Results between InfoSWMM and SWMM 5

Normally, you get the same answer in InfoSWMM and the current version of SWMM 5 for the hydrology, RDII, dry weather flow and wet weather flow but be aware that the imported SWMM 5 model had a default of 8 iterations for the number of Picard iterations whereas the imported SWMM 5 model in InfoSWMM has as default of  4 iterations.  You need to change this to 8 iterations in the Run Manager dialog of InfoSWMM to get the same routing answers.

How to Copy from a SWMM 5 Table to Excel

Subject:  How to Copy from a SWMM 5 Table to Excel

Step 1. Highlight the rows you want to copy to Excel

Step 2:  Use the Copy to Clipboard or Copy to File command

Step 3:  Paste in Excel or open the exported text file

How to Copy from a SWMM 5 Table to Excel by dickinsonre Subject:  How to Copy from a SWMM 5 Table to Excel  Step 1. Highlight the rows you want to copy to Excel  Step 2:  Use the Copy to Clipboard or Copy to File command  Step 3:  Paste in Excel or open the exported text file   via Blogger http://www.swmm5.net/2013/08/how-to-copy-from-swmm-5-table-to-excel.html

Copy and Pasted from the Dish

Copy-and-pasting Culture

Maria Popova quotes from Mark Pagel's new book, Wired for Culture: Origins of the Human Social Mind: "Having culture means we are the only species that acquires the rules of its daily living from the accumulated knowledge of our ancestors rather than from the genes they pass to us." Popova:

Language, says Pagel, was instrumental in enabling social learning — our ability to acquire evolutionarily beneficial new behaviors by watching and imitating others, which in turn accelerated our species on a trajectory of what anthropologists call "cumulative cultural evolution," a bustling of ideas successively building and improving on others. (How’s that for bio-anthropological evidence that everything is indeed a remix?)

Pagel elaborated in a recent Edge conversation:

We can all think of things that have made a difference in the history of life. The first hand axe, the first spear, the first bow and arrow, and so on. And we can ask ourselves, how many of us have had an idea that would have changed humanity? And I think most of us would say, well, that sets the bar rather high. I haven't had an idea that would change humanity. So let's lower the bar a little bit and say, how many of us have had an idea that maybe just influenced others around us, something that others would want to copy? And I think even then, very few of us can say there have been very many things we've invented that others would want to copy.

This says to us that social evolution may have sculpted us not to be innovators and creators as much as to be copiers, because this extremely efficient process that social learning allows us to do, of sifting among a range of alternatives, means that most of us can get by drawing on the inventions of others.

How to Make a Smaller Model out of a Large Model in InfoSWMM

Subject:   How to Make a Smaller Model out of a Large Model in InfoSWMM

InfoSWMM and H2OMAP SWMM will export only those ACTIVE elements to SWMM 5 as defined by the Facility Manager. 

You can use the feature to make smaller SWMM 5 models and then reimport the exported smaller SWMM 5 model back into a H2OMAP SWMM or InfoSWMM scenario.

Maximum Surcharge Height Over Crown Explanation

Note:   Maximum Surcharge Height Over Crown Explanation

Here is an example of how the Maximum Surcharge Height over the Node Crown is calculated.     Consider a manhole with an invert of 10 feet,  one incoming pipe (Pipe A), one outgoing pipe (Pipe B), both pipes with a diameter of 2 feet, but the invert  of Pipe A is 10 feet and the invert of Pipe B is 11 feet.  What is the Maximum Surcharge height if the HGL at the node is 17 feet?

                                                                                HGL at Node ---- 17 feet
                                                                                Maximum Surcharge Height Over Crown is 4 feet

                                                                                        
                                                                                Node Crown --- 13 feet         Pipe B Crown --- 13 feet                          

           Pipe A Crown --- 12 feet                          

                                                                                                                                          Pipe B Invert --- 11 feet                          
            Pipe A Invert --- 1o feet                           MH Invert --- 10 feet
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

The Importance of Viewing Results at the Proper Time Scale

Subject:   The Importance of Viewing Results at the Proper Time Scale

In SWMM 5 when you are simulating rapidly changing flow – such as pump flows – it is important to  remember that you are only seeing the results of the simulation at your selected report time step.  Here is an example model with the same number of pump starts for all three simulations (318), the same  average time step during the simulation (10 seconds) but different report time steps.  The conception of the pump starts is totally different visually depending on the selected report time steps.  You should always compare the starts using the pump graphs and the pump summary table.    The percent utilized and the number of pump start ups tells you  the mean pump start length or in this case 153 seconds or 45.1 percent of 30 hours divided by 318 pump starts.

The Importance of Viewing Results at the Proper Time Scale in SWMM5 and InfoSWMM Models by dickinsonre Subject:   The Importance of Viewing Results at the Proper Time Scale In SWMM 5 when you are simulating rapidly changing flow – such as pump flows – it is important to  remember that you are only seeing the results of the simulation at your selected report time step.  Here is an example model with the same number of pump starts for all three simulations (318), the same  average time step during the simulation (10 seconds) but different report time steps.  The conception of the pump starts is totally different visually depending on the selected report time steps.  You should always compare the starts using the pump graphs and the pump summary table.    The percent utilized and the number of pump start ups tells you  the mean pump start length or in this case 153 seconds or 45.1 percent of 30 hours divided by 318 pump starts. via Blogger http://www.swmm5.net/2013/08/the-importance-of-viewing-results-at.html

An Example of the Importance of the Term DQ4 in the SWMM 5 St Venant Solution

Subject:   An Example of the Importance of the Term DQ4 in the SWMM 5 St Venant Solution

An Example of the Importance of the Term DQ4 in the SWMM 5 St Venant Solution by dickinsonre Subject:   An Example of the Importance of the Term DQ4 in the SWMM 5 St Venant Solution The four terms are are used in the new flow for a time step of Qnew: Qnew = (Qold – dq2 + dq3 + dq4) / ( 1 + dq1) when the force main or gravity main is full dq3 and dq4 are zero and  Qnew = (Qold – dq2) / ( 1 + dq1) The dq4 term in dynamic.c uses the area upstream (a1) and area downstream (a2), the midpoint velocity, the sigma factor (a function of the link Froude number), the link length and the time step or dq4 = Time Step * Velocity * Velocity * (a2 – a1) / Link Length * Sigma where Sigma is a function of the Froude Number and the Keep, Dampen and Ignore Inertial Term Options.  Keep sets Sigma to 1 always and Dampen set Sigma based on the Froude number, Ignore sets Sigma to 0 all  of the time during the simulation. The value of dq4 increases when there is a significant difference in the cross sectional  area of the downstream end of the link and the upstream end of the link.  In this  example, the downstream storage node causes a backflow in the link.   The flow may look unstable in the link  flow time series but the change in flow is simply due to the water sloshing back and forth.  There is not continuity error as the term dq4 keeps the water in the link  in balance. via Blogger http://www.swmm5.net/2013/08/an-example-of-importance-of-term-dq4-in.html

ArcToolBox GIF in InfoSewer and InfoSWMM

Use the SWMM 5 Scatter Graph to show the Pump Curve used during the Simulation

Subject:  Use the SWMM 5 Scatter Graph to show the Pump Curve used during the Simulation

Use the SWMM 5 Scatter Graph to show the Pump Curve used during the Simulation by dickinsonre Subject:  Use the SWMM 5 Scatter Graph to show the Pump Curve used during the Simulation  You can use a scatter graph to show the relationship between the pump during the simulation and the Storage Depth.   If the pump is on the curve based on the pump summary table then the scatter graph should  look like the pump curve.  The pump summary table in the  SWMM 5 RPT also shows you the time off the pump curve low and high.   via Blogger http://www.swmm5.net/2013/08/use-swmm-5-scatter-graph-to-show-pump.html

From SciAM - Why Plants are important to River Formation

Thanks to Plants, We Will Never Find a Planet Like Earth

Earth's flora is responsible for the glaciers and rivers that have created this planet's distinctive landscape

Perhaps even more surprisingly, vascular plants formed the kinds of rivers we see around us today, according to another article by Martin Gibling of Dalhousie University in Nova Scotia and Neil Davies of the University of Ghent in Belgium, who analyzed sediment deposition going back hundreds of millions of years. Before the era of plants, water ran over Earth's landmasses in broad sheets, with no defined courses. Only when enough vegetation grew to break down rock into minerals and mud, and then hold that mud in place, did river banks form and begin to channel the water. The channeling led to periodic flooding that deposited sediment over broad areas, building up rich soil. The soil allowed trees to take root. Their woody debris fell into the rivers, creating logjams that rapidly created new channels and caused even more flooding, setting up a feedback loop that eventually supported forests and fertile plains.

"Sedimentary rocks, before plants, contained almost no mud," explains Gibling, a professor of Earth science at Dalhousie. "But after plants developed, the mud content increased dramatically. Muddy landscapes expanded greatly. A new kind of eco-space was created that wasn't there before."

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