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2.1.3 Code and input arguments
class urbanwb.pavedroof.PavedRoof(intstor_pr_t0, pr_no_meas_area, pr_meas_area, pr_meas_inflow_area, intstorcap_pr=1.6, swds_frac=1.0, discfrac_pr=0.0, **kwargs) [source]
Bases: object
Creates an instance of PavedRoof class with given initial states and properties, iterates sol() function to compute states and fluxes of Paved Roof at each time step.
Parameters:
- intstor_pr_t0 (float) – initial interception storage on Paved Roof (at t=0) [mm]
- r_no_meas_area (float) – area of Paved Roof without measure [m^2]
- pr_meas_area (float) – area of Paved Roof with measure [m^2]
- pr_meas_inflow_area (float) – measure inflow area from Paved Roof, i.e. runoff inflow area to measure from Paved Roof (>= area of Paved Roof with measure and <= total area of Paved Roof) [m^2]
- intstorcap_pr (float) – predefined interception storage capacity on Paved Roof [mm]
- swds_frac (float) – part of urban paved area with storm water drainage system (SWDS) [-]
- discfrac_pr (float) – part of Paved Roof that is disconnected from sewer system [-]
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inflowfac() [source]
Calculates measure inflow factor of Paved Roof.
Returns: Measure inflow factor of Paved Roof
- inflowfac – measure inflow factor is calculated as (runoff inflow area to measure from Paved Roof - area of Paved Roof with measure) / area of Paved Roof without measure
Return type: (float)
sol(p_atm, e_pot_ow) [source]
Calculates states and fluxes on Paved Roof during current time step.
Parameters:
- p_atm (float) – rainfall during current time step [mm]
- e_pot_ow (float) – potential Open Water evaporation during current time step [mm]
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Returns: A dictionary of computed states and fluxes of Paved Roof during current time step
- int_pr – Interception storage on Paved Roof after rainfall at the beginning of current time step [mm]
- e_atm_pr – Evaporation from interception storage on Paved Roof during current time step [mm]
- intstor_pr – Remaining interception storage on Paved Roof at the end of current time step [mm]
- r_pr_meas – Runoff from Paved Roof to measure during current time step (not necessarily on Paved Roof itself) [mm]
- r_pr_swds – Runoff from Paved Roof to storm water drainage system (SWDS) during current time step [mm]
- r_pr_mss – Runoff from Paved Roof to combined sewer system (MSS) during current time step [mm]
- r_pr_up – Runoff from Paved Roof to Unpaved during current time step [mm]
Return type: (dictionary)
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Closed Paved areas are mainly areas with paved covers like roads, parking lots, driveways, etc. that are made of impermeable material like cement and bituminous concrete pavement. In terms of conceptual modelling mechanisms, Closed Paved is quite similar to Paved Roof. On the surface of a typical impermeable paved area, a small amount of rainwater is intercepted as surface ponding which can only be emptied through evaporation. Rainfall exceeding the interception storage capacity will generate runoff, which flows to the sewer system (SWDS and/or MSS). The disconnected fraction of runoff is assumed to flow to the Unpaved area (UP). Figure 5 provides a schematic overview.
Figure 5 Schematic overview of Closed Paved (CP) in Urbanwb
2.2.1 Assumptions
- Rainwater falling on the Closed Paved is first ponded as surface interception storage and depleted by evaporation, then the excessive rainwater becomes runoff. In other words, only rainfall exceeding the interception storage capacity runs off. Provided that a very large interception storage capacity on Closed Paved is predefined, there is no runoff generated.
- Runoff on the Closed Paved is redistributed to sewer system (SWDS and MSS) and Unpaved (UP) by predefined ratios. If part of Closed Paved area is disconnected to the sewer system, that disconnected fraction of runoff flows to Unpaved area by assumption. Connected runoff on Closed Paved flows to the storm water drainage system (SWDS) or (and) combined sewer system (MSS) at predefined proportions.
2.2.2 Calculation order
- Initial interception storage on Closed Paved at the beginning of current time step is the remaining interception storage on Closed Paved at the end of previous time step plus rainfall at current time step, and it is limited by predefined interception storage capacity on Closed Paved.
- (Actual) evaporation from interception on Closed Paved during current time step is limited by potential Open Water evaporation and available initial interception storage on Closed Paved during the same time step. Evaporation is possible only if the interception storage contains water.
- (Final) interception storage on Closed Paved at the end of current time step is evaporation subtracted from initial interception storage.
- (Total) runoff from Closed Paved during current time step is rainfall subtracting actual evaporation and the change in interception storage between the same time step and previous time step. Total runoff from Closed Paved is redistributed to the measure (Meas), sewer system (SWDS and MSS) and Unpaved (UP) at predefined ratios.
- Subtracting the runoff to the measure from the total runoff is the remaining runoff. Connected remaining runoff is reallocated to storm water drainage system (SWDS) and combined sewer system (MSS) at predefined proportions while disconnected remaining runoff flows to Unpaved area (UP) at predefined ratios.
2.2.3 Code and input arguments
class urbanwb.closedpaved.ClosedPaved(intstor_cp_t0, cp_no_meas_area, cp_meas_area, cp_meas_inflow_area, intstorcap_cp=1.6, swds_frac=1.0, discfrac_cp=0.0, **kwargs) [source]
Bases: object
Creates an instance of ClosedPaved class with given initial states and properties, iterates sol() function to compute states and fluxes of Closed Paved at each time step.
Parameters:
- intstor_pr_t0 (float) – initial interception storage on Closed Paved (at t=0) [mm]
- pr_no_meas_area (float) – area of Closed Paved without measure [m^2]
- cp_meas_area (float) – area of Closed Paved with measure [m^2]
- cp_meas_inflow_area (float) – measure inflow area from Closed Paved, i.e. runoff inflow area to measure from Closed Paved (>= area of Closed Paved with measure and <= total area of Closed Paved) [m^2]
- intstorcap_cp (float) – predefined interception storage capacity on Closed Paved [mm]
- swds_frac (float) – part of urban paved area with storm water drainage system (SWDS) [-]
- discfrac_cp (float) – part of Closed Paved that is disconnected from sewer system [-]
inflowfac() [source]
Calculates measure inflow factor of Closed Paved.
Returns: Measure inflow factor of Closed Paved
- inflowfac – measure inflow factor is calculated as (runoff inflow area to measure from Closed Paved - area of Closed Paved with measure) / area of Closed Paved without measure
Return type: (float)
sol(p_atm, e_pot_ow) [source]
Calculates states and fluxes on Closed Paved during current time step.
Parameters:
- · p_atm (float) – rainfall during current time step [mm]
- · e_pot_ow (float) – potential Open Water evaporation during current time step [mm]
Returns: A dictionary of computed states and fluxes of Closed Paved during current time step
- int_cp – Interception storage on Closed Paved after rainfall at the beginning of current time step [mm]
- e_atm_cp – Evaporation from interception storage on Closed Paved during current time step [mm]
- intstor_cp – Remaining interception storage on Closed Paved at the end of current time step [mm]
- r_cp_meas – Runoff from Closed Paved to measure during current time step (not necessarily on Closed Paved itself) [mm]
- r_cp_swds – Runoff from Closed Paved to storm water drainage system (SWDS) during current time step [mm]
- r_cp_mss – Runoff from Closed Paved to combined sewer system (MSS) during current time step [mm]
- r_cp_up – Runoff from Closed Paved to Unpaved during current time step [mm]
Return type: (dictionary)
2.3 Open Paved
Open Paved areas are paths, sidewalks, parking area and other less imperviously paved areas that have relatively limited infiltration capacity. These somewhat permeable pavements use porous material that allows water flowing through it (e.g. pervious concrete, porous asphalt) or spaced nonporous material (e.g. paving stones, permeable interlocking concrete pavement) that allows water infiltrate between the cracks (Figure 6 ). Consequently, compared to the Paved Roof (PR) and Closed Paved (CP) components, the Open Paved (OP) component has an extra infiltration flux from Open Paved surface to groundwater. This infiltration flux is limited by an infiltration capacity as well as by the available interception storage on the Open Paved area. Rainfall exceeding the interception storage capacity will generate runoff, which flows to the sewer system (SWDS and/or MSS). The disconnected fraction of runoff is assumed to flow to the Unpaved area (UP). Figure 7 provides a schematic overview.
Figure 6 Permeable pavement — porous asphalt and interlocking pavement, source: google images.
Figure 7 Schematic overview of Open Paved (OP) in Urbanwb
2.3.1 Assumptions
- On Open Paved, cracks on the pavement and pores in the material that allow infiltration only occupy a very minor fraction of Open Paved surface area. Hence it does not affect the interception storage capacity on Open Paved surface.
- Infiltration starts after interception storage is filled and it is limited by predefined infiltration capacity. Interception storage can only be emptied through evaporation.
- There is no vegetation on the Open Paved area, and consequently no transpiration from root zone below the surface. Hence, for simplicity, the infiltration from Open Paved surface is directly percolating into the groundwater (GW) and passes the Unsaturated Zone.
2.3.2 Calculation order
- Initial interception storage on Open Paved at the beginning of current time step is the remaining interception storage on Open Paved at the end of previous time step plus rainfall at current time step, and it is limited by predefined interception storage capacity on Open Paved.
- (Actual) evaporation from interception on Open Paved during current time step is limited by potential Open Water evaporation and available initial interception storage on Open Paved during the same time step. Evaporation is possible only if the interception storage contains water.
- (Final) interception storage on Open Paved at the end of current time step is evaporation subtracted from initial interception storage.
- The infiltration (percolation to groundwater) occurs only if interception storage gets fully filled. Infiltration is limited by predefined infiltration capacity on Open Paved. Infiltration directly flows to groundwater (GW), i.e. percolation (skipping Unsaturated Zone).
- (Total) runoff from Open Paved during current time step is rainfall subtracting actual evaporation, the change in interception storage between the same time step and previous time step and percolation to groundwater. Total runoff is redistributed to the measure (Meas), storm water drainage system (SWDS), combined sewer system (MSS) and Unpaved (UP) at predefined ratios.
- Subtracting runoff to the measure from total runoff is the remaining runoff. Connected remaining runoff is reallocated to storm water drainage system (SWDS) and combined sewer system (MSS) at predefined proportions, whilst disconnected remaining runoff flows to Unpaved area (UP) at predefined ratio.
2.3.3 Code and input arguments
class urbanwb.openpaved.OpenPaved(intstor_op_t0, op_no_meas_area, op_meas_area, op_meas_inflow_area, intstorcap_op=1.6, infilcap_op=1.0, swds_frac=1.0, discfrac_op=0.0, **kwargs) [source]
Bases: object
Creates an instance of OpenPaved class with given initial states and properties, iterates sol() function to compute states and fluxes of Open Paved at each time step.
Parameters:
- intstor_pr_t0 (float) – initial interception storage on Closed Paved (at t=0) [mm]
- intstor_op_t0 (float) – initial interception storage on Open Paved (at t=0) [mm]
- op_no_meas_area (float) – area of Open Paved without measure [m^2]
- op_meas_area (float) – area of Open Paved with measure [m^2]
- op_meas_inflow_area (float) – measure inflow area from Open Paved, i.e. runoff inflow area to measure from Open Paved (>= area of Open Paved with measure and <= total area of Open Paved) [m^2]
- intstorcap_op (float) – predefined interception storage capacity on Open Paved [mm]
- infilcap_op (float) – predefined infiltration capacity on Open Paved [mm/d]
- swds_frac (float) – part of urban paved area with storm water drainage system (SWDS) [-]
- discfrac_op (float) – part of Open Paved that is disconnected from sewer system [-]
inflowfac() [source]
Calculates measure inflow factor of Open Paved.
Returns: measure inflow factor of Open Paved
- inflowfac – measure inflow factor is calculated as (runoff inflow area to measure from Open Paved - area of Open Paved with measure) / area of Open Paved without measure
Return type: (float)
sol(p_atm, e_pot_ow, delta_t) [source]
Calculates states and fluxes on Open Paved during current time step.
Parameters:
- p_atm (float) – rainfall during current time step [mm]
- e_pot_ow (float) – potential Open Water evaporation during current time step [mm]
- delta_t (float) – length of time step [d]
Returns: A dictionary of computed states and fluxes of Open Paved during current time step
- int_op – Interception storage on Open Paved after rainfall at the beginning of current time step [mm]
- e_atm_op – Evaporation from interception storage on Open Paved during current time step [mm]
- intstor_op – Remaining interception storage on Open Paved at the end of current time step [mm]
- p_op_gw – Percolation from interception storage on Open Paved to groundwater during current time step [mm]
- r_op_meas – Runoff from Open Paved to measure during current time step (not necessarily on Open Paved itself) [mm]
- r_op_swds – Runoff from Open Paved to storm water drainage system (SWDS) during current time step [mm]
- r_op_mss – Runoff from Open Paved to combined sewer system (MSS) during current time step [mm]
- r_op_up – Runoff from Open Paved to Unpaved during current time step [mm]
Return type: (dictionary)#### under construction ####