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

Hydrology and Environment © Objectives/Content To introduce the SimpleBase Delineation Model TM 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.

Hydrology and Environment © The SimpleBase Delineation Model TM use an independent tool for delineation of flow and level hydrographs ( ) 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

Hydrology and Environment © SimpleBase Delineation Model TM 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 )

Hydrology and Environment © Year-round or seasonally low WT; Deep river valley Kmax = 7 ÷ 9 Flow formation patterns in cross- sectional dimension Shallow drainage base: river mouth, between lakes Kmax ≤ Year-round or seasonally high WT; Shallow river valley 4 ≥ Kmax ≤ 7

Hydrology and Environment © Ct = (Qb*Cb + Qi*Ci + Qs*Cs)/Qt Ct = (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 Qt = Qb + Qi + QsQt = Qb + QiQt = Qb

Hydrology and Environment © Dissolving, processing, removing BaseInterStorm Fletcher’s Creek results: Baseflow – 58 hours ( ) Interflow hours (2.2 – 18) Storm flow – 2.2 hours (1.1 – 4.8) First rating curveSecond Third rating curve Travel time, hours Velocity and travel time separation 1 st rating curve 2 nd curve 3 rd rating curve Velocity, m3/s

Hydrology and Environment © EWBM: Equilibrium hypothesis Air temperature Evapotranspiration Tundra Desert WT Precipitation

Hydrology and Environment © EWBM: Approximations based on incompressibility 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 Hlim dQb A, km 2 r

Hydrology and Environment © 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 ) 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” (

Hydrology and Environment © Baseflow 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

Hydrology and Environment © Interflow 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)

Hydrology and Environment © Surface flow definition 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

Hydrology and Environment © Urbanization identification (clayish deposits, Y ≤ 0.1) dQb indicates seasons Kmax ≤ 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 12 3

Hydrology and Environment © Urbanization identification (sandy and rocky deposits, Y ≥ 0.2) dQb indicates seasons Kmax ≤ 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

Hydrology and Environment © Recharge fluxes Nr

Hydrology and Environment © Impact of urbanization Watershed development, % Water dynamic integrity index Nd/Nr Y = Y =

Hydrology and Environment © Drainage base beats (the SimpleBase Delineation Model application for level hydrograph delineation) Lake name Time period NdTrendRangeBLI, % ILI, % SLI, % Superior, CA – y = x Huron, CG – y= x Erie, GF – y = x – St. Clair, GH – y= x – Ontario, HC – y = x Simcoe, EA y = x

Hydrology and Environment © Conclusions The 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.

Hydrology and Environment © Acknowledgement: I am sincerely thankful to Mickey, my retired neighbour, for her help in editing of the text