Design for Environment
If there had been no primary valleys there would be no primaryridges and the main ridge would be the only shape in the landscape and stretch fromcreek to creek and the creeks would be its boundaries.
But the intrusion, so to speak, of primary valleys into thisone massive main ridge shape, gave the land three shapes and assisted in making threeland forms. The primary valleys provided higher gathering places for water and highersites for storing it below the amphitheatre where the three shapes unite and wherewater continues its attack. This is the place where the landscape can be made stronger,the focal point for improvements to be carried forward--the Keypoint for landscapedesigns.
The objective of landscape design has been stated at the endof Chapter 4, (1) to control and to use for the benefit of the landscape the waterwhich, in the natural landscapes and in the present landscapes of man, flows overthe surface of the land to the water courses, and (2) to improve the pattern of behaviourof water which falls as rain on the ridge shapes of the land, for the benefit ofthe landscape. The second is accomplished by designs for techniques which operatewithin the new design for the landscape and is dealt with in Chapter 12, Water theForest.
The first objective--the control and better use of water--isthe basis of landscape design. It is simply the addition of two new water lines tothe landscape design of Nature.
The first water line is for the better control of water, thesecond is for the improved use of water.
We start off on a farm: if the area of land to be designed hasa boundary fence which encloses only a part of the main ridge and one primary valleyand its adjacent primary ridges, the first new water line would be placed so as.to divert the run-off from rainfall on the higher land to a storage site at the Keylineof the primary valley. This is the highest site for water storage in the highestvalley of the landscape.
The storage dam in the primary valley is equipped with an outletpipe to release the water to the second new water line. It uses the stored waterto irrigate the land. Added to this plan can be a lower storage from which waterwould be pumped up to the irrigation dam.
The first new water line is a diversion channel to control therun-off water from rainfall; the second new water line is an irrigation channel towater the land. The design is made to suit the improved use of water during heavyrun-off periods which provide water beyond the absorption capacity of the (and andthe limits of the storages, (Chapter 12, Water the Forest).
These two new water lines are different from the water linesof Nature's landscape design. Whereas the natural drainage lines and water-dividelines do not touch, the new water lines cross over the drainage line of the primaryvalley and the water-divide line of the primary ridge. They may go on to cross theland and join up several primary valley drainage lines and primary ridge divide lines.In the same manner they cross over the water-divide line of a main ridge and joinup with the drainage line of a creek or stream. They may thus connect up two or manyunit-regions.
Now a concept is introduced which years ago helped solve theauthor's problem of designs for the farmscape. Called THE KEYLINE SCALE OF PERMANENCE,it is an order for planning based on the relative permanence of the various itemswhich together make up the completed landscape. In the next chapter the concept willbe applied to the design of the town and the Cityscape.
This is the scale:
The first three of the eight factors of the scale of permanence--climate,land shape and water--are THE INSEPARABLE TRINITY OF LANDSCAPE DESIGN.
The first two factors, climate and land shape, are the moreor less unalterable background of the landscape. Water, with its lines and its patternsof flow, is the first factor of the landscape design of Nature which we change.
The two new water lines added to the landscape have a fall downthe land--the same way the creek falls--but their gradient is made less than thatof the creek below. Therefore the further the two new lines are extended, the greaterthe height difference between them and the creek below, and progressively more landlies between the new water lines and the drainage line of the creek.
Water is thus retained at higher levels on the land. Beforeit may join the water courses to flow on to the sea, it must cross-over the surfaceor go through the soil of the landscape.
The new water lines for city as well as for farm, are permanentfeatures of the designed landscape. All factors below them on the scale are madeto fit in with these new but now permanent water lines.
The fourth factor, roads, fit in with the new water lines. Aroad follows alongside the diversion channel right through to the boundary. The diversionchannel with its associated road, has now added a 'zone' to the land by dividingthe main ridge and the higher parts of the primary ridges--the high catchment area--fromthe rest of the land. Another road follows along the crest line of the main ridgeto service this zone. The sites for shelter trees (the fifth factor) and for buildings(the sixth factor) with their work areas are positioned in this first zone of theland.
A second zone is added by the line of the irrigation channelwhich likewise, with its service road, divides the region from end to end. The secondzone is thus bounded by the diversion channel above, the irrigation channel below,and the boundary fence at opposite ends.
The land which contains the areas for irrigating thus lies inanother zone--the third zone of the land. This zone has a lower boundary; a channel;which controls the final overflow of water when it is in excess of the capacity ofthe soil and the storages.
The land lying between the lower boundary of the irrigationland and the creek, is yet another zone, the fourth zone of the land.
The four zones, with their service roads are connected. Thesite for this road is along the divide-lines, or centre lines, of the one or twolarge primary ridges in each unit-region. A primary ridge usually has a more or lessuniform slope from the main ridge through to the creek below.
The system of new water lines and their roads has not only addedfour zones to the regions of Nature's landscape design; it has divided those zonesin either two or in three parts by the one or two roads which connect and go throughthem. This further division of the natural regions provides the basis for the completesubdivision of the farmscape, or the cityscape--the seventh factor of the scale.
The fifth factor on the scale of permanence is trees.
Trees are absolutely essential for the health, for the balance,for the efficiency and for the aggrandisement of all the special purpose landscapesof man. If, as is said, they are second only in place to the diatoms of the seasfor the supply of atmospheric oxygen, then trees and millions more trees are essentialfor the total environment.
They must be planted or 'left' in the right places. A plant,or a tree in the wrong place is a weed.
In the farmscape some trees will be associated with the layoutof the new water lines, the roads and the fencing of the new zones. They are planted--orleft in the initial clearing of land--to shade the stock and to break the winds whichdry out the land. They provide in their leaf fall the elements from deep-down forthe balance of the soil. But in landscape design, trees have another and specialprovince. The strip forests for the farm and the City Forest for town and city, protectthe natural drainage lines and the seas from the waste products which may remainin the water that flows from the land.
The strip forests of the farmscape are located principally inthe fourth zone of the land. All water which may flow overland from the three higherzones is directed automatically into them. The water is absorbed into the deep soilof the strip forests and is cleaned and reconstituted before it flows to the streams.(Chapter 11, "Soil and Trees").
All primary valleys or perhaps even most of them do not possesssuitable sites for storing water at their Keylines; the shape of the valley musthave economic and practical significance for the purpose. If three primary valleysof the series in the one main ridge system have good storage shapes, these threevalleys govern the position of the diversion channel. Because main ridges have ageneral rise toward the top of the region, the primary valleys tend to have a progressivelyrising relationship. In the opposite direction--with the fall of the creek--it isa failing relationship. The heights of the Keylines of the selected primary valleysare determined so that the one diversion channel may fall to the first storage siteand continue beyond it to connect up with the other two sites. In this way the overflowwater from the highest storage dam follows the diversion channel to help fill thedams further on down. In like manner the second new water line--the irrigation channel--connectsup from dam to dam. When there is more water to be stared and more sites needed forstoring it, the diversion channel and the irrigation channel are repeated and connectup the new storages lower down in the primary valleys. Zones two and three are thenrepeated above zone four.
The countryside has not been divided along the natural water-dividelines or according to the unit-regions, the twin regions and the larger regions ofNature. Boundary lines of farms generally cut across natural unit-regions since somany have been determined with a straight-edge on paper. Landscape design is notsimply a matter to be applied only within the boundaries of the regions of Nature'ssubdivisions of the land, but within boundary fences. For instance, the higher boundaryof a farm may start on a main ridge and divide a unit-region by crossing over a creekand the main ridge on the other side, and may include the head and one half of thenext unit-region. The property may already have a good boundary fence, many subdivisionfences, a stock dam in each paddock, roads through the farm, a homestead, other buildingsand work areas. Moreover it may have been over-cleared of timber with trees leftonly in the steep places or standing in the "back-paddock."
Of the development work which was put in over the course ofmany years, only the boundary fence may be correctly located. There is a good chancealso that the homestead--the sixth factor of the scale--is well positioned sincethis is often decided by the womenfolk. Because they like to overlook the entranceto the farm and the work areas, the homestead--more often than not--is located ona main ridge or on the higher part of a primary ridge.
To redesign such a farm the same two new water lines dominatethe plan but there are several considerations which may determined their location.For instance on this particular property the water to be controlled does not allfall as rain on the farm, since, as one boundary fence crosses a region, water fromoutside the farm flows in via a creek. This source of water may be greater than fromrain failing on the farm itself.
Design starts with the control of the water of greatest landscapesignificance, This is invariably water of greatest quantity and lowest cost.
Firstly the entire property is examined to determine the waterresources available, to pin-point the features of the landscape and to envisage anddecide on the landscape design for the farm.
Secondly, the most advantageous place for a starting-off projectis selected. The prime requirements are that it fit the landscape design and be ofsuch significance that it will quickly enhance the overall production and value ofthe farm. It proceeds by progressively controlling all the water resources whichhave profitable significance.
While these principles of design are universal in their application,there will be only one way to design each landscape. Every special purpose landscapewill be unique; there will be no other like it on the face of the earth.
The last of the eight factors of the scale of permanence issoil.
Natural soils were not always fertile but when soil was fertileit was the great storehouse of the renewing and renewable surpluses of Nature. Inthe fertile natural grasslands and nearby forests, all the life in the landscapelived on the surpluses of Nature which had been provided by time and the reactionsof the air, the water, the rocks of the earth and the heat and the light of the sun.They have lived, bred and died for countless generations yet the surpluses of Natureremained intact. THIS IS THE BALANCE OF THE LANDSCAPE.
The history of mankind in his series of leaps and retreats typeof conquest of the earth, is the story of his discovery and exploitations of thegreat surpluses of Nature held in the soil and in the earth.
A fertile natural soil may be deprived of its fertility surplusesin a few decades as the various races of man have ably demonstrated over thousandsof years.
But there is another side to the story of soil, which will bedealt with in the Chapters "Soil Sense" and and "The Bastardisationof Agriculture". Impoverished soil can be made fertile again and soil whichwas originally low fertility, can be made deep and fertile--both in a short spaceof time.
The management of this design for the farmscape is concernedwith the improvement of the fertility of the soil. Therefore it is concerned to seethat all the wastes of the farm from plants and from the urine and the dung of animalsis absorbed again into the soil where it rightfully belongs. It is concerned to seethat water which leaves the farm does so by first being absorbed into the soil toimprove it, so that, as a coincidental, nothing from the farm may pollute the commonwaters of the land and the seas. The management of the design for the cityscape andfor all the special purpose landscapes of man is likewise concerned with these samematters.