Modelling LIDs using PCSWMM and EPA SWMM5. March 28, 2012 Presented by: Rob James (CHI) Credit to: Lewis Rossman (US EPA)

Transcription

1 Modelling LIDs using PCSWMM and EPA SWMM5 March 28, 2012 Presented by: Rob James (CHI) Credit to: Lewis Rossman (US EPA)

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3 IBM PC/AT Intel IBM PowerPC Intel Pentium III Intel Quad Core Intel i SWMM ported to minicomputer 1991 PCSWMM4 First GUI version BASIC 1998 PCSWMM 98 First GIS-based version Visual Basic 2007 PCSWMM.NET First multi-threaded version - C#,.NET PCSWMM released 1 st PC version FORTRAN 1995 PCSWMM 95 First 32-bit Windows version - Visual Basic 2002 PCSWMM 2002 Genetic algorithm based calibration PCSWMM 2011 Real-time flood forecasting Integrated 2D modeling French, Spanish, Chinese language versions 1981 EPA SWMM 3 released 1988 EPA SWMM 4 released 1993 SWMM-USERS listserv 2004 EPA SWMM 5 released

4 Processing power increase over the history of PCSWMM 100,000,000 TIMES

5 PCSWMM`s computational grid at CHI 1,000,000,000,000 FLOPS

6 So how much is 1 trillion floating point operations? 1 x 60s x 60m x 2100h x 40y 302,400,000 1,000,000,000,000 = 0.03%

7 PCSWMM: Spatial DSS for EPA SWMM5

8 PCSWMM: Spatial DSS for EPA SWMM5

9 PCSWMM/SWMM5 LID toolbox Physically-based processes Flexible components SWMM Version Simplifies the modeling of: Lot level implementations Watershed scale or city master planning Single event Continuous Performance degradation

10 Examples of SWMM5 LID controls Vegetative Swale Rain Garden Rain Barrel Street Planter Porous Pavement Infiltration Trench

11 EPA SWMM5 LID toolkit: follows the methodology of PCSWMM for PP

12 Conceptual Model of an LID Process ET Runon Overflow Underdrain Surface Zone Soil Zone Storage Zone Infiltration Percolation Infiltration

13 Flow Balance Equations d t 1 q0 e q 1 f1 1 e 1, e 2, e 3 q 0 q 1 Surface d 1 D2 f1 e2 t d t f p 3 f q p e3 f3 3 D 2 q 3 Soil Storage d 3 f 1 f p f 3

14 Ponded Depth (inches) Infiltration Rate (in/hr) Infiltration Flux Classical Green-Ampt Eqn: (depth d is normally ignored) f K sat 1 ( )( d F ) Effect of ponded depth (d) on infiltration rate (K sat = 0.5 in/hr) depth included depth ignored depth included depth ignored Time (minutes) Time (minutes)

15 Percolation Flux Rate of percolation (f p ) through the unsaturated soil zone as a function of moisture content ( is described by Darcy s Law: ( ) f p K( ) 1 D K K sat exp( ( ) HCO) 135exp( ( ) PCO) FC K = hydraulic conductivity, = capillary tension, = porosity, FC = field capacity, and HCO and PCO are coefficients.

16 Outflow Fluxes o Flux rates are functions of zone s water depth (d) o Surface zone Overland flow using Manning s formula Q = (1.49/n)AR 2/3 S 1/2 where A and R depend on d Overflow using the weir equation Q = C W L(d) 1.5 o Storage zone underdrain flow Q = C D (d) n = Manning s roughness, A = flow area, R = hyd. radius, S = surface slope, L = length of weir crest, and C w, C D, and are coefficients.

17 Representing Different LID Alternatives LID Alternative Zones Processes (besides ET) Rain Barrel Porous Pavement Infiltration Trench Surface, Storage Surface, Storage Surface, Storage Surface Overflow Storage Underdrain Flow Surface Overland Flow Storage Infiltration* Surface Overflow Storage Infiltration Vegetative Swale Surface Surface Overland Flow Surface Infiltration Bioretention Cell Surface, Soil, Storage Surface Overflow Soil Infiltration Soil Percolation Storage Infiltration* *May also include storage underdrain flow

18 Bio-retention cell Street Planter

19 LID example: Valleyfield, PQ New residential development to include 22 boulevard planters Reduce minor system inflow Reduce pollutant loading

20 Boulevard Planters

21 Alternate designs

22 Valleyfield, Quebec LID retrofit example Bio-retention cell to be installed in typical residential neighbourhood

23 PCSWMM LID representation

24 PCSWMM LID representation: surface

25 PCSWMM LID representation: surface storage

26 PCSWMM LID representation: soil

27 PCSWMM LID representation: storage

28 PCSWMM LID representation: tile drain

29 Continuous LID analysis

30 Continuous LID analysis: small events

31 Continuous LID analysis: large events

32 Continuous LID analysis: clogging potential

33 Enabling continuous LID analysis: Rainfall Processing with PCSWMM

34 Runoff (cfs) Runoff for 1-inch, 6-hr Event No Planters 3 Planters 5 Planters :00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 Rossman (2009)

35 Percent Runoff Effect of Number of Planters Number of Planters Rossman (2009)

36 Loss of Stored Water Over Time Losses (in/hr) Storage Depth (ft) Time (hrs) 36 Rossman (2009)

37 Long Term Performance 0.8 Runoff With No Planters Elapsed Time (days) Runoff With Five Planters Elapsed Time (days) Rossman (2009)

38 Olds College Demonstration Project

39 Olds College: lot-level analysis

40 Olds College: subcatchments

41 Olds College : roof to cistern

42 Olds College: roof to landscaping

43 Olds College : absorbent landscaping

44 Olds College: bio-retention area

45 Olds College : parking lot 2

46 Olds College: oil & grit separator

47 Olds College: parking lot 2

48 Olds College: permeable pavement

49 Olds College: wet pond

50 Olds College: Irrigation

51 Continuous simulation of re-use

52 Irrigation If the rainfall in the preceding two days is more than 10 mm, irrigation is delayed.

53 Irrigation Rule 1 IF SIMULATION MONTH = 5 AND SIMULATION DAY = 6 AND NODE SU_RG DEPTH = 0 AND NODE SU DEPTH > 2 THEN PUMP P1 SETTING = 1 Rule 2 IF SIMULATION MONTH = 6 AND SIMULATION DAY = 3 AND NODE SU_RG DEPTH = 0 AND NODE SU DEPTH > 2 THEN PUMP P1 SETTING = 1 Rule 3 IF SIMULATION MONTH = 6 AND SIMULATION DAY = 6 AND NODE SU_RG DEPTH = 0 AND NODE SU DEPTH > 2 THEN PUMP P1 SETTING = 1.5 ELSE PUMP P1 STATUS = OFF

54 Single event LID analysis: detention pond sizing

55 Design storm analysis: pond sizing no LIDs

56 Design storm analysis: pond sizing with LIDs

57 PCSWMM/SWMM5 LID modeling Physically-based processes Flexible components SWMM Version Simplifies the modeling of: Lot level implementations Watershed scale or city master planning Single event Continuous Performance degradation