Quality aspects of urban and natural surface runoff GEX-22967 Interventions Bassin Versant Dr. Dirk...

Quality aspects of urban and natural surface runoff

GEX-22967 Interventions Bassin Versant

Dr. Dirk Muschalla

Dr.-Ing. Dirk Muschalla

Dirk Muschalla


Literature

• Predicting Rainfall Erosion Losses : A Guide To Conservation, Agriculture Handbook Number 537, USDA– http://topsoil.nserl.purdue.edu/usle/AH_537.pdf

• W. James, W.C. Huber, R.E. Dickinson, and W.R.C. James «Water systems models HYDROLOGY», CHI, Guelph, Ontario, Canada (fourth printing 1999)– Chapters 4.8.1 - 4.8.4


Quality aspects of urban surface runoff


Urban hydrology cycle

2 3

1

7

5

4

8

1

4

8

8

6

7

2 3

1. Evapotranspiration

/precipitation

2. Runoff generation

3. Runoff concentration

4. Flow translation and

retention

5. Flow diversion and

storage

6. Overflow

7. Calculation of dry

weather flow and

pollution loads

8. Specific processes


Urban runoff quality

Three methods:

1. Average loads or concentrations• Constant concentration of surface runoff• Direct or via annual load

2. Rating curve• Concentration proportional surface runoff

3. Buildup und wash-off• Dry periods: Buildup of “dust and dirt” (DD)• Period of runoff: complete or partly wash-off of DD


Average loads / concentrations

Example ATV A128 (German guidleline document)– Annual 600 kg/ha COD– Annual precipitation 800 mm– Average runoff coefficent 0,7

lmgmm

hakgcR /

,

/107100

80070

600


Rating curve

WFLOW = subcatchment runoff (e.g. m3/s)

POFF = constituent load washed of at time t (e.g. mg/s)

RCOEF= coefficent that includes corrrect units conversion

WASHPO = exponent

WASHPOWFLOWRCOEFPOFF


Buildup

(Sartor and Boyd, 1972, Quelle:CHI 2006)


Buildup

(Pitt, 1979, Quelle:CHI 2006)


Buildup – measured Dust and Dirt

Type Land Use Pounds DD/dry day per 100 ft-curb

1 Single Family Residential 0.7

2 Multi Family Residential 2.3

3 Commercial 3.3

4 Industrial 4.6

5 Undeveloped Park 1.5

Accumulation in Chicago by APWA in 1969


Buildup – measured Dust and Dirt

Parameter Single Family Residential

Multi Family Residential

Commercial Industrial

BOD5 5.0 3.6 7.7 3.0

COD 40.0 40.0 39.0 40.0

Total Coliforms

1.3 106 2.7 106 1.7 106 1.0106

Total N 0.48 0.61 0.41 0.43

Total PO4 0.05 0.05 0.07 0.03

Accumulation in Chicago by APWA in 1969Milligram of pollutant per gram of DDUnits for coliforms are MPN/gram


Buildup Equations

DDLIMDD

tDDFACTDD DDPOW

Three different equations

1.Power-linear

2.Exponential

3.Michaelis-Menton

DD=Dust and Dirt (e.g. lb)

)1( tDDPOWeDDFACTDD

tDDFACT

tDDLIMDD


Buildup


Washoff

Rate of washoff (e.g.mg/sec) is proportional to remaining quantity

PSHETKdt

dPSHED

PSHED = quantity remaining on surfaceK = coefficient


Washoff

tkePSHETtPSHED 0)(

)1()( 0tkePSHETtPOFF

PSHED(t) = quantity remaining on surface at time t

PSHED0 = initial amount of quantityPOFF = cumulativ amount washed of at

time t


Washoff modification

rRCOEFK

PSHETrRCOEFdt

dPSHED WASHPO

» if increase of in runoff rate is sufficient, concentration can increase during the middle of

a strom even if PSHED is dimished «


CSO– discharge receiving river

0

0.5

1

1.5

2

2.5

3

3.5

4

8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00

Ab

flu

ss [

m³/

s]

Einleitung + 1000m + 2000m + 3000m


CSO – resulting BOD5 concentration

0

5

10

15

20

25

30

35

40

45

8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00

BS

B5 [

mg

/l]

Einleitung + 1000m + 2000m + 3000m


Quantity (PSHED) on surface over time

0

1

2

3

4

5

6

7

8

9

185 192 199 206 213 220 227 234 241 248 255 262 269 276

Tage

P(t

) [k

g B

SB

5/ha

]

Pmax=3, K1=0.12 Pmax=6, K1=0.12 Pmax=9, K1=0.12 Pmax=6, K1=0.06 Pmax=6, K1=0.18

0

1

2

3

4

5

6

7

8

9

1 8 15 22 29 36 43 50 57 64 71 78 85 92

Tage

P(t

) [k

g B

SB

5/ha

]



0

1

2

3

4

5

6

7

8

9

185 192 199 206 213 220 227 234 241 248 255 262 269 276

Tage

P(t

) [k

g B

SB

5/ha

]


0

1

2

3

4

5

6

7

8

9

93 100 107 114 121 128 135 142 149 156 163 170 177 184

Tage

P(t

) [k

g B

SB

5/ha

]



0

1

2

3

4

5

6

7

8

9

185 192 199 206 213 220 227 234 241 248 255 262 269 276

Tage

P(t

) [k

g B

SB

5/ha

]



Rainfall event

0

0,3

0,6

0,9

1,2

1,5

1,8

16:30 16:55 17:20

Nie

der

sch

lag

[m

m]

hN hNeff


Hydro- and Pollutograph

0

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

16:30 16:55 17:20

Ab

flu

ss [

m³/

s]

0

0,015

0,03

0,045

0,06

0,075

0,09

0,105

0,12

BS

B5

[kg

/(h

a*m

in)]

Abfuss SchmutzfrachtK2=2.0, w=0.6


POFF over time

0

0,3

0,6

0,9

1,2

1,5

1,8

2,1

16:30 16:55 17:20 17:45

Po

ten

tial

BS

B5 [

kg/h

a]

SchmutzfrachtK2=2.0, w=0.6


M (V) diagram

1.0 2.0 3.0

0.2

0.6

1.0

Relative Frachtsummenkurven für BSB5

S BSB5 1.680 [kg/ha], max. BSB5 0.087 [kg/(ha*min)] S BSB5 1.917 [kg/ha], max. BSB5 0.107 [kg/(ha*min)] S BSB5 1.952 [kg/ha], max. BSB5 0.116 [kg/(ha*min)]


Abtragskoeffizient K2

Fo

rmfa

kto

r w


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 20% 40% 60% 80% 100%

Abfluss

BS

B5

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 20% 40% 60% 80% 100%

Abfluss

BS

B5

0.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

70.00%

80.00%

90.00%

100.00%

0.00% 20.00% 40.00% 60.00% 80.00% 100.00%

Abfluss

BS

B5

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 20% 40% 60% 80% 100%

Abfluss

BS

B5

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 20% 40% 60% 80% 100%

Abfluss

BS

B5

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 20% 40% 60% 80% 100%

Abfluss

BS

B5

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 20% 40% 60% 80% 100%

Abfluss

BS

B5

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 20% 40% 60% 80% 100%

Abfluss

BS

B5

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 20% 40% 60% 80% 100%

Abfluss

BS

B5


Quality aspects of natural surface runoff


Upland processes

Upland Processes


Hydrology

Erosion

Plant Growth

Nutrient Cycling

Pesticide Dynamics

Agricultural Management

Upland Processes


Root Zone

Shallow (unconfined)

Aquifer

Vadose (unsaturated)

Zone

Confining Layer

Deep (confined) Aquifer

Precipitation

Evaporation and Transpiration

Infiltration/plant uptake/ Soil moisture redistribution

Surface Runoff

Lateral Flow

Return Flow

Revap from shallow aquifer

Percolation to shallow aquifer

Recharge to deep aquifer

Flow out of watershed

Hydrologic Balance


2 10840

0

9

6

3

12

Month

LAI

126

Plant Growth


NO3- NH4

+

Soil Organic Matter

NO2-

manures, wastes and

sludge

ammonium fixationclay

mineralization

immobilization

nitrification

immobilization

Symbiotic fixation

NO3

-

anaerobicconditions

N2

N2O

NH3Atmospheric N fixation

leaching

fertilizer fertilizer

Harvest

denitrification

ammonia volatilizati

on

runoff

Nitrogen Cycle


Soil Organic Matter

H2PO4-

HPO4-2

manures, wastes and

sludge

mineralization

immobilization

fertilizer

Harvest

manures, wastes, and

sludge

Adsorbed and fixed Inorganic

Fe, Al, Ca, and clay

runoff

Phosphorous Cycle


Foliar Application

Degradation

Washoff

Infiltration

Leaching

Runoff

Surface Application

Degradation

Pesticide dynamics


Erosion

Effects on environmental quality and productivity

• Loss of organic matter, clay and nutrients reduces productivity

• Damage to plants

• Formation of rills and gullies affects management

• Sedimentation in waterways, diversions, terraces and ditches

• Delivery of nutrients to surface water


Types of soil erosion


Soil water erosion process

Soil

Sediment LoadSediment Transport

Detachment

Deposition


Deposition

Transport capacity=

sediment load

Sediment production less than transport

capacity

Deposition because sediment production exceeds transport capacity

Hill slopeTransport capacity

Sediment load


Erosion plot

©Ali Fares

Dr.-Ing. Dirk Muschalla©Ali Fares


©Ali Fares


USLEUniversal Soil Loss

EquationWischmeier, W.H. and D.D. Smith. 1978.

Predicting rainfall erosion losses. USDA Agriculture Handbook 537, U.S. Department of

Agriculture.


USLEUniversal Soil Loss Equation

• A = average annual soil loss (tons/acre year)• R = rainfall and runoff erosivity index• K = soil erodibility factor• L = slope length factor• S = slope steepness factor• C= crop/management factor• P = conservation or support practice factor

PCLSKR A


USLEUniversal Soil Loss Equation

• Empirical model: – Analysis of observations– Seeks to characterize response from these data.

• Based on:– Rainfall pattern, soil type, topography, crop system and

management practices.

• Predicts:– Long term average annual rate of erosion

• Subroutine in models such as:– SWRRB (Williams, 1975), EPIC (Williams et al., 1980), ANSWERS

(Beasly et al., 1980), AGNPS (Young et al., 1989)


R (rainfall and runoff erosivity index)

• Erosion index (EI) for a given storm:– Product of the kinetic energy of the falling

raindrops and its maximum 30 minute intensity.

• R factor = S EI over a year / 100


Average annual values of the rainfall erosion index (R).


K (soil erodibility)

• Susceptibility of a given soil to erosion by rainfall and runoff.

• Depend on: – Texture, structure, organic matter content, and

permeability.

A =R x K x LS x C x P


Soil-erodibility nomograph


LS (slope length-gradient)

Ratio of soil loss under given conditions to that at a site with the "standard" slope and slope length.



Topographic LS factor


C (crop/management)

Ratio of soil loss from land use under specified conditions to that from continuously fallow and tilled land.


Crop FactorGrain Corn 0.40

Silage Corn, Beans & Canola 0.50Cereals (Spring & Winter) 0.35

Seasonal Horticultural Crops 0.50Fruit Trees 0.10

Hay and Pasture 0.02

Tillage FactorFall Plow 1.00

Spring Plow 0.90Mulch Tillage 0.60Ridge Tillage 0.35Zone Tillage 0.25

No-Till 0.25


P (conservation practices)

• Ratio of soil loss by a support practice to that of straight-row farming up and down the slope.


Support Practice P Factor

Up & Down Slope 1.00

Cross Slope 0.75

Contour farming 0.50

Strip cropping, cross slope 0.37

Strip cropping, contour 0.25


MUSLE

Modified Universal Soil Loss Equation

V = surface

qp = is the peak flow rate

K = erodibility factor

C = crop management factor

P = the erosion control practice factor

LS = slope length and steepness factor.

PCLSK )q (V 11.8 = Y 0.56p


MUSLE

Modified Universal Soil Loss Equation

The MUSLE was developed by replacing the rainfall-energy factor in the USLE with a runoff energy factor

K, LS, C and P are the standard USLE factors

MUSLE is e.g. used in SWAT

PCLSK )q (V 11.8 = Y 0.56p


CONTOUR STRIP CROPPING

Crawford CO


Terracing & Contour Farming


Contour cropping Strip cropping

Buffer strips Vegitated creeks

Quality aspects of urban and natural surface runoff GEX-22967 Interventions Bassin Versant Dr. Dirk...

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