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

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

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.

Friday, August 17, 2012

Benefits of Urban Trees


If you’re interested in the subject of the community benefits of trees, you can get additional information from the websites of the National Arbor Day Foundation and theUS Forest Service.  Among the tidbits I learned on one or the other of those two sites are these:
  • The net cooling effect of a young, healthy tree is equivalent to ten room-size air conditioners operating 20 hours a day.
  • If you plant a tree today on the west side of your home, in 5 years your energy bills should be 3 percent less. In 15 years the savings will be nearly 12 percent.
  • One acre of forest absorbs six tons of carbon dioxide and puts out four tons of oxygen. 
  • A number of studies have shown that real estate agents and home buyers assign between 10 and 23 percent of the value of a residence to the trees on the property.
  • Surgery patients who could see a grove of deciduous trees recuperated faster and required less pain-killing medicine than matched patients who viewed only brick walls.
  • In one study, stands of trees reduced particulates by 9 to 13 percent, and the amount of dust reaching the ground was 27 to 42 percent less under a stand of trees than in an open area.
  Bethesda, MD (c2012 FK Benfield)
Several years ago, walkability guru Dan Burden wrote a detailed monograph titled 22 Benefits of Urban Street Trees.  Among other things, he calculated that “for a planting cost of $250-600 (includes first 3 years of maintenance) a single street tree returns over $90,000 of direct benefits (not including aesthetic, social and natural) in the lifetime of the tree.”  Burden cites data finding that street trees create slower and more appropriate urban traffic speeds, increase customer traffic to businesses, and obviate increments of costly drainage infrastructure.  In at least one recent study (reported after Burden’s analysis), trees were even found to be associated with reduced crime.

Thursday, August 16, 2012

Fifty Years of Watershed Modeling – Past, Present and Future

Fifty Years of Watershed Modeling –
Past, Present and Future
September 24-26, 2012
Boulder, Colorado
On behalf of Engineering Conferences International and the conference chairs, Anthony S. Donigian, Jr. (AQUA TERRA Consultants), andRichard Field (US Environmental Protection Agency/ORD [retired], Michael J. Baker Jr., Inc.), it is my pleasure to extend this invitation to you to participate in Fifty Years of Watershed Modeling – Past, Present and Future to be held September 24-26, 2012 at NCAR (National Center for Atmospheric Research – Center Green Campus) in Boulder, Colorado.
Continuous Simulation using SWMM 5 LID and Groundwater Features in a Linked 1D/2D Network using InfoSWMM 2D for a 50 Year Period

has been accepted for Poster Presentation at the forthcoming conference Fifty Years of Watershed Modeling: Past, Present and Future to be held September 24-26, 2012 at National Center for Atmospheric Research (NCAR – Center Green Campus) in Boulder, Colorado.

Huff Distribution SWMM 5 Model

Saturday, August 11, 2012

A SWMM 5 Model made from the Art of Jack Yerka

Subject:   A SWMM 5 Model made from the Art of Jack Yerka

A SWMM 5 Model made from the Art of Jack Yerka

by dickinsonre
Subject:   A SWMM 5 Model made from the Art of Jack Yerka

The attached example SWMM 5 model has small rectangular conduits with a constant inflow based on a background image from Jack Yerka.

Friday, August 10, 2012

How to use the Flow Splitter in InfoSewer for Dendritic Networks

Subject:  How to use the Flow Splitter in InfoSewer for Dendritic Networks

How to use the Flow Splitter in InfoSewer for Dendritic Networks

by dickinsonre
Subject:  How to use the Flow Splitter in InfoSewer for Dendritic Networks

InfoSewer, which is an extension in Arc Map, does need to have flow splits defined where gravity mains merge together to determine the amount of flow in each of the downstream conduits (Figure 1).   The options for the flow splitterin each of the downstream links are:
1.       Automatic Allocation
2.       Fixed Flow Percentage
3.       Variable Flow Percentage and
4.       Inflow-Outflow Curve 
At an outfall where the invert of the outfall pipe is raised compared to the inverts of the incoming and outgoing pipes a flow split of Variable Flow Percentage or Inflow/Outflow curve may work better (Figure 2). 

Figure 1. Options for Performing a Flow Split in InfoSewer

Figure 2.  The Effect of the flow split can be used to model complex situations in a dendritic model with outfalls.

Thursday, August 9, 2012

How to Export all of your Data to a Shapefile Using InfoSWMM

Subject:  How to Export all of your Data to a Shapefile Using InfoSWMM

How to Export all of your Data to a Shapefile Using InfoSWMM

by dickinsonre
Subject:  How to Export all of your Data to a Shapefile Using InfoSWMM

You can do this easily by using three steps which are shown in Figure 1, Figure 2 and Figure 3.

Figure 1.  Export Manager Tool

Figure 2.  Link and Node Export Options
Figure 3. Parameter options for Export to the Shapefile

Friday, August 3, 2012

Rules for NRSCS Unit Hydrographs in InfoSWMM

Subject:  Rules for NRSCS Unit Hydrographs in InfoSWMM

Rules for NRSCS Unit Hydrographs in InfoSWMM and H2OMap SWMM

by dickinsonre
Subject:  Rules for NRSCS Unit Hydrographs in InfoSWMM and H2OMap SWMM

Rules or Guidelines for NRSCS Unit Hydrographs if used as the Hydrology Option in InfoSWMM and H2OMAP SWMM:
1.       The Unit Hydrograph CN comes from the Subcatchment Table and the NRCS_CN Column
2.      Time of Concentration is from the TC column in the Subcatchment Table
3.      The Infiltration Model should be from the CN infiltration Model Column in the Subcatchment Database Table
4.      The CN in the Soil Database Table should be the same as the CN in the Subcatchment Database Table
5.      If the Depression Storage is zero in the Subcatchment Database Table then the Initial Abstraction in inches will be calculated as 0.2*(1000/CN-10) internally in the engine
6.      Initial Abstraction or IA in US Units =  0.2*(1000/CN-10) in American Units

AI Rivers of Wisdom about ICM SWMM

Here's the text "Rivers of Wisdom" formatted with one sentence per line: [Verse 1] 🌊 Beneath the ancient oak, where shadows p...