Light industrial

The light industrial node assigns the said land use to a specific GIS-delineated area: this involves (1) the generation of urban form with a likeness to that occupying the land use zone in question, (2) alteration of the land cover within the region, and (3) employment of a unique water demand profile for the parcels created as part of the zoning.

The initial urban form abstraction utilises the workflow that comprises the residential node, with the corresponding parameters fixed so that the properties of the blocks, parcels and buildings that are generated reflect an idealised area of light industrial land use. The set parameters are informed by multiple sources, including DELWP’s Urban Design Guidelines for Victoria, the Austroads Guide to Road Design, Vicmap Planning land use data and PSMA’s building footprint and cadastral datasets, and are based on an ideal theorised adaptation area that creates city blocks with dimensions equal to the respective inputs (this allows the downstream calculation of parcel/building inputs to be specified for the land use in question).

Table 1. Fixed residential node parameters

Parameter

Value

Units

City block width

180

m

City block length

120

m

Street offset

5.25

m

City parcel width

54.75

m

City parcel height

42.375

m

Building length

40

m

Building width

25

m

Building height

7.5

m

Hardstand fraction

0.82

Irrigation ratio

0.8

City block width and length are taken from Element 1 of the Urban Design Guidelines for Victoria (DELWP 2017), which outline ranges of 60m to 240m for block width/length and a target of 600m for the block perimeter; the final parameters values were settled on through the use of Austroads Guide to Road Design Part 4A: Unsignalised and Signalised Intersections (Austroads 2017), where the safe intersection sight distance (based on the anticipated speed limit and traffic composition of the land use) was calculated and used as the limiting block dimension – the opposing dimension was then taken as the length that results in the target block perimeter being engendered.

The street offset value was derived from the Austroads Guide to Road Design Part 3: Geometric Design (Austroads 2016), according to assumptions of the characteristics of the roads contained within the land use zone (industrial access; two-way traffic with parallel parking on both sides).

The value for the parcel width was obtained by halving the length of the city block after applying the relevant offset; the figure for parcel length was found by first specifying a median parcel area for the land use zone in question (accomplished through investigation of the corresponding Vicmap Planning and PSMA datasets for a Melbourne LGA), and then setting the parameter input to a value that would result in the modelled parcel area most closely replicating this median term, factoring for the requirement of having the offset city block width divisible exactly by the parcel length (i.e. the parcel length that creates a lot possessing the median area is increased or decreased slightly to ensure a round number of parcels are generated from the division of the block).

Building length and width was decided upon through the use of the building coverage ratio (BCR) deduced from the analysis of the PSMA cadastral and building data – the parcel area resulting from the respective cited length and width inputs is multiplied by the BCR to establish an approximate idealised building size. Then, building dimensions which serve to most closely replicate the aspect ratio of the characterised parcel are chosen to engender this said area (building height is taken as the median denoted as part of the building footprint dataset).

The land use’s hardstand fraction is inherited from Melbourne Water’s MUSIC Modelling Guidelines (Melbourne Water 2018) – the hardstand area is assumed as impervious fraction minus roof fraction, which is taken as the BCR; the irrigation ratio is the default of that of any passively irrigated open space, per SA Water’s Code of Practice for Irrigated Public Open Space (SA Water 2008).

It is to be noted that the node’s workflow does not exactly follow that of the base residential node – the operations responsible for generating new trees are removed, functionality that removes any existing trees intersecting the region of interest is introduced, and a module that serves to set the number of employees accommodated by each parcel engendered for the land use is incorporated into the workflow.

The employee count module functions in one of two ways: either the number of employees per parcel is calculated based on a formula, or, if a total employee count for the adaptation region is entered, this figure is distributed equally between all parcels. All employee counts are rounded to the nearest integer, and a negative value for the total number of employees cannot be entered (the value resets to zero).

../_images/zoning_formula_1.png
Table 2. Employee count calculation variables

Variable

Value

Description

N_E

Number of employees calculated for the given layer feature

N_F

Median building height divided by assumed floor height

B_H

7.5

Median building height

F_H

4

Assumed floor height

A_F

Area of the light industrial layer feature in square metres

BCR

0.45

Building coverage ratio (i.e. what proportion of the lot is covered by the building footprint)

NUAR

0.65

Net usable area ratio (i.e. the proportion of practical usable area within a building)

CF

1.3

Compliance factor (estimation of the tolerance given to the area per person value)

A_P

50

Area per person (i.e the floor space of a building required for every occupant) in square metres

The established median building height was used as part of determining the number of floors of a building (a storey was taken as four metres, per the assumption used by the Department of Planning and Community Development); net usable area and area per person were taken from The Architect’s Handbook (Pickard 2008) and the Building Code of Australia (ABCB 2016), respectively (the compliance factor was calculated by dividing the recommended area per person for an office from the former, by the minimum area per person from the later).

Following the urban form characterisation and the allocation of employees to the parcels of the land use zone, the microclimate grid is updated to reflect the nature of the land cover of the zone. The microclimate grid proportions are indicative of the information prompting the parcel hardstand fraction and irrigation ratio values, and are applied to the entire region used by the adaption node (except for the street offset area of the city blocks, which contributes a complete road proportion to the intersecting grid cells).

Table 3. Land cover proportions

Land cover

Fraction of microclimate grid cell

Tree

0.00

Water

0.00

Dry Grass

0.02

Irrigated Grass

0.08

Roof

0.45

Road

0.00

Concrete

0.45

The final element of the light industrial adaptation node involves the assignment of the said land use zone to a zoning attribute attached to the parcel – the attribute is used to filter for a water demand model profile specific to the land use in question.

Table 4. End-use demand rates

End-use

Demand rate

Units

Leakage

0

L/p/d

Washing machine

32.15

L/p/d

Tap

99.04

L/p/d

Toilet

3.81

L/p/d

Shower/bath

0

L/p/d

The end-use terms for the demand profile are in litres per capita per day, and are calculated by first establishing a gross demand rate for the land use – in this case, this is done through referencing the conference paper ‘Residential and Non-Residential Water Use Factors for the Atlanta Region’ (Turner et al. 1997) and taking the wholesale sector as representative of light industry. The cited daily per capita rate is then scaled down to account for the working week and partitioned according to a report published by the Pacific Institute, ’Waste Not, Want Not: The Potential for Urban Water Conservation in California’ (Cain et al. 2003). From the report, meat, dairy, produce, beverage, textile, pulp and technology sectors were categorised as light industry; and water for industrial processes was taken as equivalent to the tap end-use; and water for heating and cooling was taken as equivalent to the washing machine end-use.