Permaculture Designers Manual
CHAPTER 4 – PATTERN UNDERSTANDING
Section 4.26 –
Additional Pattern Applications in Permaculture
A sophisticated application of pattern is found in the herb spiral (Figure 4.30) which I evolved in 1978 as a kitchen-door design.
All the basic culinary herbs can be planted in an ascending spiral of earth on a 2 m wide base, ascending to 1 or 1.3 m high.
All herbs planted on the spiral ramp are accessible. The construct itself gives variable aspects and drainage, with sunny dry sites for oil-rich herbs such as thyme, sage, and rosemary, and moist or shaded sites for green foliage herbs such as mint, parsley, chives, and coriander.
This is a rare three-dimensional earth construct on a small scale, and compactly coils up a linear path or bed of herbs into one mound at the kitchen door, thus malting the herbs accessible and convenient to the kitchen itself if kitchens are not at ground level, roof or balcony gardens can carry pot herbs in stepped walls, on wall shelves, in window boxes, or as stacks of pots in earth mounds.
Pattern analyses can also be applied to water conservation.
For example, a mulch-pit (60 cm wide and deep), surrounded by a planting shelf and spill bank totaling 1.2 m (4 feet) across has a 3.8 m (12 foot) perimeter but can be efficiently watered with one low-pressure sprinkler, whereas a 3.8 m straight row takes three such sprinklers.
Another advantage is the central (one-drop) mulch pit, so that the plants eventually over shade the center to prevent evaporation. Such circle, mulch, grow pits are made 1.8 m (6 feet) across for bananas, and 1.8-3 m (6-10 feet) across for coconuts; all out produce row crop for about one-third of the water use.
A series or set of such gardens greatly reduce the path space and land area needed for home gardens, or orchards of banana and coconut (Figure 4.31).
A field application of patterned ground designed to direct flow, and capture materials in flow, is that of flood-plain embankments or tree lines (poplar, willow, tamarack), or both combined.
These are very effective pattern impositions on landscape (although all occur naturally as rock dykes or resistant rock strata in the field) that can have several beneficial effects for a household or settlement nearby (Figure 4.32).
A more conscious and portable applied pattern set is that of the “Flow form” models being developed at the Virbella Institute by a small group of artist technicians.
Such turbulence basins are apparent in nature as shaped basins in streams flowing over massive sandstones or mudstone rocks.
They are even in antiquity modeled in pozzelanic cement by Roman hydrologists.
Flow forms are artificial replicates of the rock forms carved by turbulent streams, cast in concrete or fiberglass (Figure 4.33).
Stacked in sets below sewage pipe outfalls or above fish ponds at pipe inlets, they efficiently mix air and water by inducing turbulence in flow.
Three distinct mixing effects are noticeable; the first a plunge or vertical overturn as fluid drops from one basin to another; the second as a figure-8 or lateral flow around the basins themselves; and the third (a fascinating process) as an interaction between these two, as water coursing around the basins deflects the vertical drop flow and switches it from side to side in a regular rhythm.
Within these major turbulence patterns [so dearly portrayed by da Vinci (Popham, A.E., The Drawings of Leonardo da Vinci, Jonathan Cape, London, 1946) and further analyzed in terms of computer models and catastrophic theory by Chappell (in: Landform Evolution in Australia, ANU Press, Canberra 1978) for coastal up rush and backwash turbulence] are distinct vortices and counter flow, over folds and cusps that further mix air and water at the edges of the basins and in the main flow stream.
Thus, artificial Flow form basins induce aeration, oxidize pollutants and are themselves aesthetically pleasing and instructive hydrological pattern-models of naturally-occurring constructs.
They have practical use in the primary treatment of sewage and organically polluted waters and in the oxygenation of ponds for aquatic species production.
Models of this type are the result of a long evolution beginning with wonder, sketches, analysis, observations, and then proceeding via constructed hydrological basins to practical applications over a wide variety of sites.
In nature and in the Flow form system, the basins can be elongate, truncate, symmetrical, asymmetrical, stepped in line, stacked like ladders or spiraled to conserve space.