Keep and Dampen options and their effect on the four main terms of the St Venant equation

Note:  The Keep and Dampen options and their effect on the four main terms of the St Venant equation. 

The Keep and Dampen options and their effect on the four main terms of the St Venant equation in SWMM5 by dickinsonre Note:  The Keep and Dampen options and their effect on the four main terms of the St Venant equation.  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 dq3 term in dynamic.c uses the current midpoint area (a function of the midpoint depth), the sigma factor and the midpoint velocity. dq3 = 2 * Velocity * ( Amid(current iteration) – Amid (last time step) * Sigma dq1 = Time Step * RoughFactor / Rwtd^1.333 * |Velocity| The weighted area (Awtd) is used in the dq2 term of the St. Venant equation: dq2 = Time Step * Awtd * (Head Downstream – Head Upstream) / Link Length or dq2 = Time Step * Awtd * (Head Downstream – Head Upstream) / Link Length Normally, dq1 (Friction Loss / Maroon in the Graph) balances dq2 (Water Surface Slope Term or Green in the Graph) but often for links with a large difference between upstream and  downstream depths dq4 (Red in the Graph) can have a significant value.  If dq4 or dq3 are important then the depth of water to increases to pass the same flow using the Keep option over the Ignore.   If you have a link with a Froude number near or over 1.0 (Supercritical) then using Keep or Dampen  for the Options may result in depth differences.   The effect of Keep is to increase the "loss" terms in the St VenantEquation.   The effect of Dampen and Ignore is to decrease the sum of the "loss" terms in the St. Venant Solution and lower the simulated depth. via Blogger http://www.swmm5.net/2013/08/the-keep-and-dampen-options-and-their.html

Stream Names in the USA

Stream Names in the USA from http://derekwatkins.wordpress.com/2011/07/25/generic-stream-terms/

Generic place names (or toponyms) such as Cumberland Gap or Mount Rainier provide general categorical descriptions of a geographic feature, in contrast to specific toponyms, which provide a unique identifier: Lake Huron. This map taps into the place names contained in the USGS National Hydrography Dataset to show how the generic names of streams vary across the lower 48. Creeksand rivers are symbolized in gray due to their ubiquity (although the etymology behind the American use of creek is interesting), while bright colors symbolize other popular toponyms.

Lite-Brite aesthetic notwithstanding, I like this map because it illustrates the range of cultural and environmental factors that affect how we label and interact with the world. Lime green bayous follow historical French settlement patterns along the Gulf Coast and up Louisiana streams. The distribution of the Dutch-derived term kill (dark blue) in New York echoes the colonial settlement of “New Netherland” (as well as furnishing half of a specific toponym to the Catskill Mountains). Similarly, the spanish-derived terms rio, arroyo, and cañada (orange hues) trace the early advances of conquistadors into present-day northern New Mexico, an area that still retains some unique cultural traits. Washes in the southwest reflect the intermittent rainfall of the region, while streams named swamps (desaturated green) along the Atlantic seaboard highlight where the coastal plain meets the Appalachian Piedmont at the fall line.

Green Roof LID Control in SWMM 5

Subject:  Green Roof LID Control in SWMM 5

I saw this on the Daily Dish, http://andrewsullivan.thedailybeast.com/2011/07/roo.html, it is an extremely green roof but a roof that can be simulated in SWMM 5.  You simulated it as a Bio Retention Cell with a Surface, Soil, Storage and an Underdrain to the Gutters of the roof.  You can also have a rain barrel connected to the gutters to storage and drain the rainfall. 

Philadelphia Low Impact 
Development Symposium

Greening the Urban Environment

September 25-28, 2011, Philadelphia, PA

Image courtesy of Philadelphia Water Dept.

• Home
• Program
• Abstract Submission
• Registration
• Contact Us

Sunday, September 25, 2011

9:00am - 4:30pm Pre-Conference Workshops
9:00am - 12:00pm - LID 101: Basic Concepts and Applications
9:00am - 12:00pm - Extensive Green Roof Design for Civil/Stormwater Engineers
1:00pm - 4:30pm - LID 201: Design Guidelines for LID Practices
1:00pm - 4:30pm - Permeable/Pervious Pavement

Workshop descriptions can be found by clicking here.

Pre-Conference Workshops
9:00am - 4:30pm
Commonwealth Rooms

Monday, September 26 - Plenary Session

Mr. Howard Neukrug 
Commissioner
Philadelphia Water Department

We are pleased to have Commissioner Howard Neukrug of the Philadelphia Water Department as our Plenary Speaker. Commissioner Neukrug has been the driving force behind the Green City, Clean Waters approach to solutions to the city's Combined Sewer Overflow challenges. Links to the city's plan can be found here:http://www.phillywatersheds.org/what_were_doing/documents_and_data/cso_long_term_control_plan/

Joining Commissioner Neukrug in welcoming the participants will be:

• Robert G. Traver, PhD, PE, WRE, Professor and Director, VCASE and VUSP, Conference Chair
• Tom Davenport - Director, EPA 319 Non Point Source Monitoring Program
• Glen Rider, Director, Bureau of Watershed Management, PA DEP
• Shawn M. Garvin, Administrator for EPA's Mid-Atlantic Region

Photo Courtesy of the Philadelphia Water Department.

Plenary
Monday, 8:30 am
Regency Ballroom

Chesapeake Bay Panel - "LID and the Chesapeake TMDL"

Moderator: Robert G. Traver, PhD, PE, WRE 
Professor and Director, VCASE and VUSP,
Conference Chair

The purpose of this panel is to discuss the role of LID in meeting the TMDL requirements for Nitrogen and Phosphorus reductions in the Chesapeake Bay. Each panelist will be asked to first make a brief overview of their thoughts on the issue. A moderated discussion will follow based upon submitted questions to the moderator. Please feel free to submit questions prior to the conference to the moderator.
(Image Source – USEPA Chesapeake Bay Program Office)

Panel
9:30 am
Regency Ballroom

LID-MARC

Moderator: Bill Hunt, PhD, PE 
Associate Professor, NC State University
Conference Co-Chair

Present and Future Directions with LID Research

Bill Hunt, NC State University
Allen Davis, University of Maryland
Robert Traver, Villanova University

Plenary, Cont'd
10:00 am
Regency Ballroom

Technical Sessions

	Track I	Track II	Track III	Track IV	Track V	Track VI	Track VII	Track VIII
	SCMs I	SCMs II	Assessing LID	Plan & Stnd	Cities & Streets	Models & CSOs	Outreach & Codes	319 & Chesapeake
Monday, September 26, 2011
10:50am	LID/MARC	Monitoring	LID Econ I	DesStand I	Sustain & LID I	Filter/Manuf	Outreach I	319 I
1:40pm	Bioret I	Harscape I	LID Econ II	DesStand II	Sustain & LID II	Models I	Outreach II	319 II
3:40pm	Bioret II	Hardscape II	Metrics	DesStand III	Streets I	Models II	Outreach II	319 III
Tuesday, September 27
8:30am *5*	NonStruct	Philly	VolRed I	Muni Pln I	DC 1	CSOs 1	W'shed Pln I	Ches Fed
10:55am	Bioret III	G. Roof I	VolRed II	Muni Pln II	Streets II	City Pln I	Outreach IV	Panel
1:45pm	Bioret IV	G. Roof II	Attenuat'n	City Pln II	Streets III	Models III	Regs & Code I	319 IV
3:45pm	Media	G. Roof III	Extreme LID	City Pln III	Streets IV	Models IV	Regs & Code II	319 V
Wednesday, September 28
8:30am *5*	O & M	W. Harvest I	Ecology	W'shed Pln II	DC II	CSOs II	Transprt I	Case Studies
10:55am		W. Harvest II	Campus	Climate Ch	Transprt II	CSOs III	Regs & Code III	319 VI

Wednesday, September 28, 2011

Field Tours - 1:00 - 4:30pm
Tour A - Villanova Urban Stormwater SCM Research and Demonstration Park
Tour B - Reinventing the Neighborhood (PWD)
Tour C - Urban LIDs (PWD)
Tour D - Stroud Preserve and Stroud Water Research Center 319 NPS National Monitoring Site

Tour descriptions can be found by clicking here.

Link Here  

Field Tours 
1:00pm - 4:30pm

Updated July 18, 2011