Tuesday, October 9, 2012

SWMM 5 Control Rules for Pumps

Subject:  SWMM 5 Control Rules for Pumps

If you want to define the setting for a pump between the Pump On and Pump Off depths then an IF statement based on the Pump flow will work better as in this example, which changes the setting for the pump between a depth of 18 and 20 meters.   The IF statement based on flow will ensure the rule only applies when the Pump Control depth is moving from the Pump On depth to the Pump Off depth and NOT between the Pump Off and Pump On depth.  Figure 1 shows how the Pump Flow is related to the Pump Setting.

RULE CONTROL_Rule2
IF PUMP PUMP1 FLOW > 0.000000
AND NODE WELL HEAD > 18.000000
AND NODE WELL HEAD < 20.000000
THEN PUMP PUMP1 SETTING = 0.700000
PRIORITY 2.000000
Figure 1   Pump Flow is related to the Pump Setting



Saturday, October 6, 2012

Hydrology and Floodplain Analysis (5th Edition)

Hydrology and Floodplain Analysis (5th Edition) [Hardcover]

Philip B. Bedient (Author), Wayne C. Huber (Author), Baxter E. Vieux (Author)
This text offers a clear and up-to-date presentation of fundamental concepts and design methods required to understand hydrology and floodplain analysis. It addresses the computational emphasis of modern hydrology and provides a balanced approach to important applications in watershed analysis, floodplain computation, flood control, urban hydrology, stormwater design, and computer modeling. This text is perfect for engineers and hydrologists.   The book does have large sections on SWMM 5 and HEC-RAS along with Radar Rainfall and 2D flow modeling.

Lambda Calculus and Link Variables in the InfoSWMM, H2OMAP SWMM and SWMM 5 Dynamic Wave Solution

Subject:  Lambda Calculus and Link Variables in the InfoSWMM, H2OMAP SWMM and SWMM 5 Dynamic Wave Solution

Successive under-relaxation for the SWMM 5 Dynamic Wave Solution

by dickinsonre
Subject:  Successive under-relaxation for the SWMM 5 Dynamic Wave Solution
SWMM 5 uses the method of Successive under-relaxation to solve the Node Continuity Equation and the Link Momentum/Continuity Equation for a time step.  The dynamic wave solution in dynwave.c will use up to 8 iterations to reach convergence before moving onto the next time step.  The differences between the link flows and node depths are typically small (in a non pumping system) and normally converge within a few iterations unless you are using too large a time step.  The number of iterations is a minimum of two with the 1st iteration NOT using the under-relaxation parameter omega. The solution method can be term successive approximation, fixed iteration or Picard Iteration, fixed-point combinatory, iterated function and Lambda Calculus. In computer science, iterated functions occur as a special case of recursive functions, which in turn anchor the study of such broad topics as lambda calculus, or narrower ones, such as the denotational semantics
In the SWMM 5 application of this various named iteration process there are three main concepts for starting, iterating and stopping the iteration process during one time step:
·         The 1st guess of the new node depth or link flow is the current link flow (Figure 3) and the new estimated node depths and link flows are used at each iteration to estimate the new time step depth or flow.  For example, in the node depth (H) equation dH/dt = dQ/A the value of dQ or the change in flow and the value of A or Area is updated at each iteration based on the last iteration's value of all node depths and link flows. 
·         A bound or a bracket on each node depth or link flow iteration value is used by averaging the last iteration value with the new iteration value.  This places a boundary on how fast a node depth or link flow can change per iteration – it is always ½ of the change during the iteration (Figure 1).  

·         The Stopping Tolerance (Figure 2) determines how many iterations it takes to reach convergence and move out of the iteration process for this time step to the next time step.
Figure 1.  Under relaxation with an omega value of ½ is done on iterations 2 through a possible 8 in SWMM 5. This is not done for iteration 1.
Figure 2.  if the change in the Node Depth is less than the stopping tolerance in SWMM 5 the node is considered converged.  The stopping tolerance has a default value of 0.005 feet in SWMM 5.0.022. 


Figure 3.  The differences between the link flows and node depths are typically small (in a non pumping system) and normally converge within a few iterations unless you are using too large a time step.  The number of iterations is a minimum of two with the 1stiteration NOT using the under-relaxation parameter omega.

St. Venant equation – this is the link attribute data used when the St. Venant Equation is used inSWMM 5, H2OMAP SWMM and InfoSWMM.  Simulated Parameters from the upstream, midpoint and downstream sections of the link are used.


Normal Flow Equation – this is the link attribute data used when the Normal Flow Equation is used in H2OMAP SWMM. Only simulated parameters from the upstream end of the link are used if the normal flow equation is used for the time step.  The normal flow equation is used if the flow is supercritical or the water surface slope is less than the bed slope of the link.


Non Linear Term in the Saint Venant Equation of SWMM 5

The flow equation has six components that have to be in balance at each time step:
1. The unsteady flow term or dQ/dt
2. The friction loss term (normally based on Manning's equation except for full force mains),
3. The bed slope term or dz/dx
4. The water surface slope term or dy/dx,
5. The non linear term or d(Q^2/A)/dx and
6. The entrance, exit and other loss terms.
All of these terms have to add up to zero at each time step. If the water surface slope becomes zero or negative then the only way the equation can be balanced is for the flow to decrease. If the spike is due to a change in the downstream head versus the upstream head then typically you will a dip in the flow graph as the water surface slope term becomes flat or negative, followed by a rise in the flow as the upstream head increases versus the downstream head.
You get more than the normal flow based on the head difference because in addition to the head difference you also get a push from the non linear terms or dq3 and dq4 in this graph.
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Tuesday, October 2, 2012

Innovyze President Dr. Paul F. Boulos Named Chair of the Lebanese American UniversityBoard of Trustees


Innovyze President Dr. Paul F. Boulos Named
Chair of the Lebanese American UniversityBoard of Trustees
Broomfield, Colorado USA, October 2, 2012 — Innovyze, a leading global innovator of wet infrastructure modeling and simulation software and technologies, today announced that its president and chief operating officer, Dr. Paul F. Boulos, has been named chairman of the Board of Trustees of the Lebanese American University (LAU) in Beirut, Lebanon. Dr. Boulos succeeds Dr. Charles Elachi, director of NASA’s Jet Propulsion Laboratory (JPL) and Vice President of the California Institute of Technology, who has served as chair since 2009.
Dr. Boulos has held key leadership roles as a member of the LAU Board of Trustees since 2009, including serving on the Executive, Audit, and Nominating committees, and chairing the Advancement committee. He also served as chair of the LAU Board of International Advisors from 2006 to 2009.
A renowned international authority on water resources and navigation engineering, Dr. Boulos has co-authored nine authoritative books and more than 200 technical articles on issues critical to the water and wastewater industry. He is the recipient of numerous honors from national and international scientific and engineering societies, governments, universities, and NGOs. Among these acknowledgements are notable technical awards for excellence in scholarship from the American Society of Civil Engineers, the American Water Works Association and the U.S. Environmental Protection Agency.
Dr. Boulos also received the U.S. Ellis Island Medal of Honor, one of America’s highest accolades; the Pride of Heritage Award from the Lebanese American Foundation; the Alumni of the Year Award by LAU; and was inducted into the University of Kentucky College of Engineering Hall of Distinction, the highest honor the university bestows on its alumni. He was also recognized with Honorary Diplomate status by the American Academy of Water Resources Engineers as well as Distinguished Diplomate status in Navigation Engineering by the Academy of Coastal, Ocean, Port & Navigation Engineers, both academies’ top honors. He is a Fellow of the American Society of Civil Engineers and a Diplomate (by Eminence) of the American Academy of Environmental Engineers.
Dr. Boulos serves on the Board of Trustees of the American Academy of Water Resources Engineering (Reston, VA); the Boards of Directors of Innovyze, MWH Global (Broomfield, CO) and America-Mideast Educational and Training Services, Inc./AMIDEAST (Washington, D.C.); and the Dean’s International Council of the Harris School of Public Policy Studies at the University of Chicago (Chicago, IL). He has been a member of advisory boards and councils for many organizations, including the Advisory Council of the Buck Institute for Research on Aging (Novato, CA), the Arab American National Museum (Dearborn, MI), the USEPA Science Advisory Board, the Urban Water Resources Research Council of the Environmental and Water Resources Institute, and the National Academy of Sciences/National Research Council.
Dr. Boulos received his Doctorate, Master of Science, and Bachelor of Science degrees in Civil Engineering from the University of Kentucky as well as a Bachelor degree in General Science from the Lebanese American University. He has also completed Harvard Business School’s Advanced Management Program.
The President of LAU, Dr. Joseph G. Jabbra, hailed as historic the appointment of Dr. Paul Boulos, as Chairman of the LAU Board of Trustees. “This is the first time in the history of LAU that the Chairman of the Board of Trustees is an alumnus of our beloved institution,” he said. “Dr. Boulos is passionately committed to the well-being of his Alma Mater and to its continued success. He also brings to this position a bundle of energy and a great deal of knowledge and experience. LAU is indeed honored to have Dr. Boulos as the Chairman of its Board of Trustees. Under his dynamic leadership, his Alma Mater will continue its meteoric rise.”
One of the top academic institutions in the Middle East, LAU is a private American not-for-profit higher education institution, and is fully accredited by the Commission on Institutions of Higher Education (CIHE) of the New England Association of Schools and Colleges (NEASC), one of the most esteemed authorities on higher education in the world. It has over 8,200 students (representing seventy-five nationalities) enrolled in seven major schools: Arts and Sciences, Business, Architecture and Design, Engineering, Medicine, Nursing, and Pharmacy. The latter is the only Pharm. D. program accredited outside the United States. Over 1,800 students graduate from LAU each year, and its alumni are employed at leading companies around the world. The university has over 250 faculty members and two campuses, in Beirut and Byblos. It is building a third campus in New York.
Founded by the Presbyterian Church, USA, in 1924, LAU is governed by a Board of Trustees which derives its authority from the Board of Regents of the University of the State of New York. The Board of Trustees consists of 25 members, most of them American, and is responsible for ensuring that the university furthers its mission organizationally, administratively, educationally, spiritually, socially, and financially. It also assures that LAU has adequate facilities and sets the policy framework for the university’s administration.
“It is an honor to follow Dr. Charles Elachi, who has done a phenomenal job of supporting the forward movement of the University as Chair,” said Boulos. “I received an excellent education at LAU, one that I continue to draw on each and every day. I can leave no better legacy than to work diligently to ensure that the LAU we pass on to future generations is even better than the one that so profoundly affected our lives. LAU is an extraordinary place with an inspirational history, and it’s entering an exciting new phase of rapid growth. We are building one of the world’s finest universities, providing our students with the richest educational experience possible as we prepare the next generation of leaders, problem-solvers, and creative thinkers and doers for Lebanon, the MENA region, and the world. I look forward to working with the board, the president, and the vibrant LAU community in the coming years to realize that vision.”
For more information on LAU, visit www.lau.edu.

Saturday, September 8, 2012

How to Use Trace Upstream, Domain Manager and Facility Manager in InfoSewer to Find the CE

Subject:   How to Use Trace Upstream, Domain Manager and Facility Manager in InfoSewer to Find the CE

How to Use Trace Upstream, Domain Manager and Facility Manager in InfoSewer to Find the CE

by dickinsonre
Subject:   How to Use Trace Upstream, Domain Manager and Facility Manager in InfoSewer to Find the CE

InfoSewer does not have table of node continuity errors only an overall continuity error balance.  If you have a continuity error then you can use the process of divide and conquer to find the continuity error.  Start at the Outlets and using the Trace Upstream command, Domain Manager and Facility Manager take out whole sections of the network until you isolate the section of the network with the continuity error.    Here are the steps you can take:

Step 1.             Use Trace Upstream Network to find the and place in a Domain the Upstream Network (Figure 1).
Step 2.                          Once the upstream domain is created use the Domain Manager to add in any extra links without nodes (Figure 2)
Step 3.             Make the Domain Inactive using Facility Manger (Figure 3)
Step 4.                        Run the network and check the overall continuity error (Figure 4)
Step 5.                         Continue and repeat until you isolate the area that is the main source of the Continuity Error (CE).

Figure 1.  Trace Upstream Network and Place it in a Domain

Figure 2.  Use Domain Manager to take out links without nodes

Figure 3.  Use Facility Manager to Make the Domain Inactive
Figure 4.  Find and Isolate the Area with the CE.








Tuesday, September 4, 2012

InfoSWMM (d/D v. Surcharge d/D)

Subject:   InfoSWMM (d/D v. Surcharge d/D)

What is the difference between the output variables d/D and Surcharge d/D in InfoSWMM and H2OMap SWMM

The d/D is calculated as link capacity based on the midpoint depth of water in the link or Link depth/ Link Maximum Depth
            Since the depth in the link is restricted to the Maximum Depth the d/D value is always between 0 and 1
The Surcharged d/D is calculated from the end node depths at each end of the link
            The two node depths are averaged and the value of Surcharge d/D is the Average Node Depth / Link Maximum Depth,
The value of Surcharge d/D varies from 0 to a large number depending on the maximum depths of the nodes and the possible surcharge depth of the nodes

The value of d/D is based on the middle of the link and the value of Surcharge d/D is based on the average of the node depths at the end of the link.  They may be and often are different.   However, if you have a Surcharge d/D greater than 1 it will indicate at least one end of the link is surcharged.  A Surcharge d/D may be greater than 1 with a d/D less than 1 due to the ends of the node being surcharged and not surcharged.

·         A Surcharged d/D indicates that at least one end of the link is Full, but
·         A d/D value less than 1 does not preclude that one end may be Surcharged.


InfoSWMM (d/D v. Surcharge d/D)

by dickinsonre
Subject:   InfoSWMM (d/D v. Surcharge d/D)

What is the difference between the output variables d/D and Surcharge d/D in InfoSWMM and H2OMap SWMM

The d/D is calculated as link capacity based on the midpoint depth of water in the link or Link depth/ Link Maximum Depth
            Since the depth in the link is restricted to the Maximum Depth the d/D value is always between 0 and 1

The Surcharged d/D is calculated from the end node depths at each end of the link

            The two node depths are averaged and the value of Surcharge d/D is the Average Node Depth / Link Maximum Depth,
The value of Surcharge d/D varies from 0 to a large number depending on the maximum depths of the nodes and the possible surcharge depth of the nodes

The value of d/D is based on the middle of the link and the value of Surcharge d/D is based on the average of the node depths at the end of the link.  They may be and often are different.   However, if you have a Surcharge d/D greater than 1 it will indicate at least one end of the link is surcharged.  A Surcharge d/D may be greater than 1 with a d/Dless than 1 due to the ends of the node being surcharged and not surcharged.

·         A Surcharged d/D indicates that at least one end of the link is Full, but
·         A d/D value less than 1 does not preclude that one end may be Surcharged.

Figure 1.  Plot of d/D and Surcharged d/D in InfoSWMM.



Monday, September 3, 2012

Reasons A Pump H-Q Curve may be Different than the Design Curve

Subject:   Reasons A Pump H-Q Curve may be Different than the Design Curve

From Allan R. Budris and Water World

Actual system H-Q curve not known:
The actual current system H-Q curve may be different than the original system design. Once a plant is commissioned and the plant is put in service, the system head begins to change. In the short term, levels change in the tanks and wells, valves open and close, and filter screens become clogged. As maintenance occurs, pipe schedules are changed, equipment is changed and new equipment is added into the system. In the long term, equipment loses efficiency, scale forms on the internal pipe walls and the plant undergoes expansion and contraction. Even when new, the original calculated system curve may differ from the actual system performance due to the assumptions used in the calculation, such as 10 year old pipe. Any pump change should, therefore, start with the development (confirmation) of the true current pumping system “Head-Capacity” curve, as detailed in the writer’s January 2009 Column on: “Creating an Accurate Pumping System Head-Capacity Curve...“ A field test of the pump total developed head at one or more measured flow rates can help determine the actual (current) pump and system H-Q curves. By developing the true system head-capacity curve, an accurate determination of the current and new pump operating conditions can be established.

Additional references on aging pumps




From Pump System Hydraulic Design 10.2.4 Determination of Pump Operating Points—Single Pump
The system curve is superimposed over the pump curve; (Fig. 10.6). The pump operating points occur at the intersections of the system curves with the pump curves. It should be observed that the operating point will change with time. As the piping ages and becomes rougher, the system curve will become steeper, and the intersecting point with the pump curve will move to the left. Also, as the impeller wears, the pump curve moves downward. Thus, over a period of time, the output capacity of a pump can decrease significantly. See Fig. 10.7. for a visual depiction of these combined effects
.


Saturday, September 1, 2012

Storage Nodes in InfoSWMM and H2OMAP SWMM

Subject:   Storage Nodes in InfoSWMM and H2OMAP SWMM

Figure 1 shows how to use the various constants, coefficients and exponents in the Storage or Wet Well data of H2OMAP SWMM.     If you have a Wet Well or Storage Diameter you should convert the Wet Well diameters into an Area with the units of either square feet or square meters.  The computed area will then be a constant or coefficient in the Attribute Browser.  You would only use the exponent or a table of depth and area if the Wet Well area varies with depth. 
Figure 1.  Options for Defining a Storage Node in H2OMAP SWMM or SWMM 5





Wednesday, August 29, 2012

Singapore NEWater Program

From Toilet To Tap

Paul Rozin argues that we need to overcome our disgust with recycled water. He offers Singapore's NEWater as an example of effective marketing: 
Four treatment plants throughout the country take sewage, filter it through several membranes, and expose it to ultraviolet light to make it safe to drink. Now 30 percent of the country’s total water demand is met using reclaimed (i.e., recycled) sewage. The program’s success was due in part to a dedicated communications team that conducted a massive public education campaign, which included a TV documentary. But Singapore also made the decision to release the cleaned-up wastewater into reservoirs, where it got re-treated along with regular tap water. This extra step was hygienically redundant but psychologically vital in helping Singaporeans accept NEWater as a fact of life.
The above animation was created by primary school students in Singapore.

Monday, August 27, 2012

God Created the World, But the Dutch Created the Netherland

God Created the World, But the Dutch Created the Netherlands

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Horace Dediu's presentation on the history of Amsterdam features the amazing land reclamation map above. Utrecht, which is now inland, used to be a port. And Amsterdam is where the ocean used to be. Haarlem is part of the mainland but looks to be located on what was once a barrier island.
It's a commonplace of economics that they're not making any more land, but this is a powerful reminder that once upon a time it was actually pretty common for technologically advanced societies to build more land. Leaving that era behind us is probably a good idea (imagine the environmental impact review!), but that only makes it all the more important to try to use the land we do have wisely.

Indoor Plumbing Is an Amazing Invention

Indoor Plumbing Is an Amazing Invention

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A young woman washes her face at a newly built deep water well in 2010
Photo by Roberto Schmidt/AFP/Getty Images.
Robert Gordon has a working paper out making some not-particularly-persuasive, super-pessimistic, speculative claims about the future of American economic growth that does include, as an aside, this very persuasive observation about consumer surplus:
A thought experiment helps to illustrate the fundamental importance of the inventions of [Industrial Revolution] #2 compared to the subset of [Industrial Revolution] #3 inventions that have occurred since 2002. You are required to make a choice between option A and option B. With option A you are allowed to keep 2002 electronic technology, including your Windows 98 laptop accessing Amazon, and you can keep running water and indoor toilets; but you can’t use anything invented since 2002.
Option B is that you get everything invented in the past decade right up to Facebook, Twitter, and the iPad, but you have to give up running water and indoor toilets. You have to haul the water into your dwelling and carry out the waste. Even at 3am on a rainy night, your only toilet option is a wet and perhaps muddy walk to the outhouse. Which option do you choose?
The answer, obviously, is that indoor plumbing is more important than the combination of everything that's been invented in the past 10 years. Indoor plumbing is a really amazing invention.
But I think it's actually quite important to not mix and match arguments about subjective utility with arguments about GDP and economic growth. I'd gladly give up small kitchen appliances (toasters, microwaves, coffee machines, food processors, and even my beloved immersion blender) rather than Wikipedia. Giving all that stuff up would be annoying, but I could make coffee with a French press, and I'd really hate to lose Wikipedia. But the high subjective value I place on Wikipedia doesn't change the fact that the manufacture, sale, distribution, and marketing of small kitchen appliances is a substantial industry creating tons of jobs and economic activity in a way that Wikipedia doesn't. These are just different things.
Still—take a moment to sit back and try to appreciate the stupendous difference in your quality of life that comes to you courtesy of indoor plumbing.

Thursday, August 23, 2012

How Does Horton Infiltration Work in SWMM 5?

How Does Horton Infiltration Work in SWMM 5?

by dickinsonre
This sketch summarizes what happens in a SWMM 5 Subcatchment for Horton Infiltration during a storm event:

1.       The event starts out with the potential infiltration rate at the maximum infiltration rate but
2.      Decay starts happening right away and the potential infiltration rate starts decreasing until it reaches the minimum infiltration rate (assuming the storm last long enough),
3.      The actual infiltration rate is the minimum of the rainfall rate or the potential infiltration rate,
4.      Using the Huff distributions for rainfall the runoff does not start happening until the rainfall rate exceeds the potential infiltration rate in these models
5.      The runoff ceases after the rainfall rate becomes less than the current potential infiltration rate later in the storm,
6.      The maximum infiltration volume for Horton caps the storm event infiltration at 10 mm in this example, the infiltration will cease when the cumulative infiltration reaches 10 mm.
7.      Horton Iniltration is a five parameter method
a.      Maximum infiltration rate in mm/hour
b.      Minimum infiltration rate in mm/hour
c.       Decay rate for the change from maximum to minimum infiltration rate
d.      Regeneration rate for the change from minimum to maximum infiltration rate after the storm event ends and
e.      A maximum infiltration volume per storm event in millimeters


Saturday, August 18, 2012

SWMM 5 Weir RTC Rules

Subject:   SWMM 5 Weir RTC Rules

SWMM 5 Weir RTC Rules

by dickinsonre
Subject:   SWMM 5 Weir RTC Rules

This example SWMM 5 model closes a weir based on the depth at the upstream node of the Weir every 0.25 feet.  You can see the effect of the RTC rules using a Scatter plot of Weir Flow versus Weir Depth in SWMM 5 (Figure 1).   The Weir flows normally every 0.25 feet but shuts down three times using these rules which set the Weir Setting to 0.0

RULE Weir100
IF Node  WeirNode Depth > 1.75
AND Node WeirNode Depth < 2.0
THEN WEIR WEIR Setting = 0.0
Priority 2

RULE Weir101
IF Node  WeirNode Depth > 2.25
AND Node WeirNode Depth < 2.5
THEN WEIR WEIR Setting = 0.0
Priority 2

RULE Weir102
IF Node  WeirNode Depth > 2.75
AND Node WeirNode Depth < 3.0
THEN WEIR WEIR Setting = 0.0
Priority 2

RULE Weir103
IF Node  WeirNode Depth > 3.25
AND Node WeirNode Depth < 3.5
THEN WEIR WEIR Setting = 0.0
Priority 2

RULE Weir104
IF Node  WeirNode Depth > 3.75
AND Node WeirNode Depth < 4.0
THEN WEIR WEIR Setting = 0.0
Priority 2

Figure 1.  Scatter Graph of Weir flow versus Weir Node Depth.

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