Hydrology and Environment © The hydrological limits of urbanization R. Vedom Hydrology and...

Hydrology and Environment ©

The hydrological limits of The hydrological limits of urbanizationurbanization

R. VedomR. VedomHydrology and EnvironmentHydrology and Environment

905 823 6088905 823 [email protected]@can.rogers.com

www.hydrology.cawww.hydrology.ca


Objectives/ContentObjectives/Content

• To introduce the SimpleBase Delineation ModelTM and its use

• to describe the flow formation process in terms of the model parameters

• to give definitions of the flow components obtained by this new hydrological tool

• based on the obtained results of flow separation for heavily urbanized watersheds to show how their parameters can quantitatively indicate the impact of urbanization.


The SimpleBase Delineation The SimpleBase Delineation ModelModelTMTM use use

• an independent tool for delineation of flow and level hydrographs (2002-2005)

• in the Equilibrium Water Balance Model, EWBM (2004)

• of the water quality formation process in the Separated Flow Approach (2003/2006)

the accurate

an auxiliary devise

the essential principle


SimpleBase Delineation ModelSimpleBase Delineation ModelTMTM

0

10

20

30

40

50

60

70

dQb

Nd

Baseflow delineation algorithm: if (Qt)t – (Qt)t-1 > dQb,

, otherwise (Qb)t = (Qt)t,The key point for delineation is the mathematical definition of a discharge flux, which is the increase of the flow followed by its

decrease or unchanged condition

(Qb)t = (Qt)t-1 + dQb

dQi = dQb*2^(Kmax + 0.618)


Year-round or seasonally low WT;

Deep river valley

Kmax = 7÷ 9

Flow formation patterns in cross-Flow formation patterns in cross-sectional dimensionsectional dimension

0

Shallow drainage base: river mouth, between lakes

Kmax ≤ 3

350

-40.0

-35.0

-30.0

-25.0

-20.0

-15.0

-10.0

0

-5.0

0.0

Year-round or seasonally high WT;

Shallow river valley

4 ≥ Kmax ≤ 7


Ct = (Qb*Cb + Qi*Ci + Qs*Cs)/QtCt = (Qb*Cb + Qi*Ci)/Qt

Ct = Cb

Ct, Qt - Total flow concentration and discharge

Cb, Qb - Baseflow concentration and discharge

Ci, Qi - Interflow concentration and discharge

Cs, Qs - Surface flow concentration and discharge

The Separated Flow Approach concept (stream quality formation process)

In different phases of water regime each flow component has different patterns

20

30

40

50

60

70

80 Qt = Qb + Qi + Qs

Qt = Qb + Qi

Qt = Qb


Dissolving, processing, removingDissolving, processing, removing

20

0

40

60

80

100

120

140

1 11 21 31 41 51 61 71 81 91 101 111 121 131

Base Inter StormFletcher’s Creek results: Baseflow – 58 hours (17 -122)Interflow - 6.8 hours (2.2 – 18)Storm flow – 2.2 hours (1.1 – 4.8)

First rating curve Second Third rating curve

Tra

vel

tim

e, h

ou

rs

0

1

2

3

4

5

6

1 11 21 31 41 51 61 71 81 91 101 111 121 131

Velocity and travel time separation

1st rating curve 2nd curve 3rd rating curve

Vel

oci

ty,

m3/

s


EWBM: Equilibrium hypothesisEWBM: Equilibrium hypothesis

Air temperature

Evapotranspiration

Tundra Desert

WT

Precipitation


EWBM: Approximations based on EWBM: Approximations based on incompressibility of waterincompressibility of water

• Hlim - head of water table above the lowest stream level, within which the relation between H and I is linear

• r - radius of a circle, which area is equal to the area of the watershed

HlimdQb

A, km2

r

A, km2


Global regularities Global regularities

dQb corresponds to the highest Nd• Manifestation of main physical features of water,

continuity and incompressibility, in hydrosphere: the response of a river system to a recharge flux due to incompressibility of water displays degree of water continuity in air, water, and ground media.

dQi = dQb*2^(K + 0.618)• Law of Structural Harmony of System: “The Generalized

Golden Sections are invariants, which allow natural systems in process of their self-organization to find harmonious structure, stationary regime of their existence, structural and functional stability” (www.goldenmuseum.com)


Baseflow definitionBaseflow definition• The baseflow component of

river flow is the permanently continual inter-river groundwater discharge into the stream transmitting all drainage media and estimated by the dynamic uniformity limit dQb, the limit of uniform response of the drainage system to a recharge event: atmospheric water pressure flux– The lowest uniform area

sink in EWBM (2004)

L


Interflow definitionInterflow definition

• Interflow is the temporary component of the river flow, which continuity is limited by the filtration and storage capacity of the river valley alluvial deposits and weathering zone.– Dynamic buffer

(2005)


Surface flow Surface flow definitiondefinition

• The surface or storm component of the river flow is the unbonded highly aggressive portion of the stream flow with a very short lifetime lasting from the continuity breakage until expanding over the flood plain for water bond restoration– “Bonding plate”

1

2

3


Urbanization identification Urbanization identification (clayish deposits, Y (clayish deposits, Y ≤ 0.1≤ 0.1))dQb indicates seasonsKmax ≤ 9, SFI ≤ 1% Nd « Nr

Weak indication of seasons Kmax ≥ 9, K = 7 SFI = 1 ÷ 10% Nd < Nr

No seasonal indication Kmax > 9, K = 5 SFI » 10% Nd ≤ Nr

1 2

3


Urbanization identification Urbanization identification (sandy and rocky deposits, Y (sandy and rocky deposits, Y ≥ 0.2≥ 0.2))

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0

0.5

1

1.5

2

2.50

1

2

3

4

5

6

7

8

dQb indicates seasonsKmax ≤ 4, SFI «1%, Nd ≤ Nr

Weak indication of seasons Kmax ≈ 9, K = 5, SFI = 5 ÷ 20%, Nd ≤ Nr

No seasonal indication Kmax > 9, K = 5, SFI » 20%, Nd ≤ Nr

1

2

3


Recharge fluxes NrRecharge fluxes Nr

1

Precipitation Air temperature

Water fluxes in warm period,

Heat fluxes in cold period

Nr = 52 ÷ 60/year (Southern Ontario)


Impact of urbanizationImpact of urbanization

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 20 40 60 80 100 120

Watershed development, %

Wat

er d

ynam

ic in

teg

rity

ind

ex N

d/N

r

Y = 0.01-0.1 Y = 0.1 - 0.25


Drainage base beats Drainage base beats (the SimpleBase Delineation Model application for (the SimpleBase Delineation Model application for levellevel

hydrograph delineation)hydrograph delineation)

Lake name

Time period

Nd Trend Range BLI,%

ILI,%

SLI,%

Superior, CA003

1966 – 2000 66 y = 0.1313x + 61 47 - 79 90.3 5.7 4.0

Huron, CG002

1966 – 2000 71 y= -0.0936x + 73 57 - 80 89.7 7.7 2.6

Erie, GF002

1966 – 2000 67 y = 0.1647x + 64 45 – 77 95.9 0.7 3.4

St. Clair, GH005

1966 – 2000 58 y= -0.0364x + 58 29 – 70 88.6 8.0 3.4

Ontario, HC048

1950 – 2000 67 y = 0.1155x + 64 47 - 83 98.5 1.0 0.5

Simcoe, EA014

1966 - 2000 69 y = 0.0899x + 67 43 - 83 95.6 4.1 0.3


ConclusionsConclusionsThe SimpleBase Delineation ModelTM is manifestation of main physical features of water, continuity and incompressibility, in entire hydrosphere: the response of a river system to a recharge flux due to incompressibility of water displays degree of water continuity in air, water, and ground media.

The certainty of the flow components’ definitions and regularity of their relationships opens a new possibility for quantitative assessment of the urbanization impact.

Hydrologically, the urbanization process can be identified as the process of gradual limitation of spatial interface between atmospheric and groundwater resulting in a continual drought.

The dynamic integrity index Nd/Nr for different geological conditions in combination with K and SFI determines the degree of the surface and groundwater disintegration, sustainable limits of which may be identified as the limits of urbanization.


Acknowledgement:

I am sincerely thankful to Mickey, my retired neighbour,

for her help in editing of the text

Hydrology and Environment © The hydrological limits of urbanization R. Vedom Hydrology and...

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