Previous Section | Table of Contents | Next Section

6.0.0  LANDSCAPE DOCUMENTATION

6.1.0  Levels and types of landscape documentation
6.2.0  Procedure for researching site plans
6.3.0  Procedure for measuring sites
6.4.0  Procedure for drawing preliminary site plans
6.5.0  Inking site plans

6.1.0  LEVELS AND TYPES OF LANDSCAPE DOCUMENTATION

6.1.1  HABS undertakes various types of landscape documentation.  These variations require differing recording techniques and degrees of accuracy, and result in different final products:

1.  sites immediately surrounding and associated with
     documented structures;
2.  parks, formal and informal gardens;
3.  archaeological sites;
4.  city plans;
5.  heritage corridors.

6.1.3  Comprehensive documentation is usually undertaken to record parks and gardens as entities in themselves.  The drawings may include historical and developmental maps, topographical surveys, planting lists (including common and botanical designations), hardscape and furniture materials lists, elevations, details and site sections.  Depending on the size of such sites, overall plans can be drawn to the common engineering scales or to the smaller architectural scales.  Drawings focussing on particular areas, furniture and details will be produced at 1/8" = 1'-0" or larger, and will require measuring to 1/4" or closer.

6.1.4  Large sites combining structure and landscape such as fortifications may require maps which show the development of the fortifications, quarters, support structures and ordnance.  In addition to the maps, plans, elevations, sections, details and axonometrics may be required to support future restoration work. The resulting drawings will need to reflect a very high degree of accuracy.  (Plans of such structures are often drawn at 1/8" = 1'-0" on 24" x 36" sheets, with match lines.  The images are then reduced photographically, and their negatives are spliced together and re-shot to make a new "inter-negative".  This new negative is then used to produce photo-drafting films of the entire plan.)
 

6.2.0  PROCEDURE FOR RESEARCHING SITE PLANS

6.2.1  Depending on the nature of the documentation project, a site plan will complement historical and architectural information presented on structures, or will stand alone.

6.2.2  Previous site surveys, photographs and historical descriptions can provide valuable insights into site development over time, the prevailing condition and topography.  This information can be used to plan the continuation of the physical survey.  If an existing survey is available, it be used to determine the scale of future drawings.  Changes in scale can be made through the photographic process, or by the grid method, although the latter is less accurate and time consuming. 

6.2.3  Plant identification.  If a landscape architect is not available, local horticulturalists, nursery personnel, agricultural agents and garden club members are all excellent sources.  Take close-up photographs of leaves, flowers, fruit and bark, and if necessary, carefully collect samples.  Finally, numerous plant identification publications are available--especially Hortus III.

6.2.4  Nomenclature.  Planting lists must always include common and botanical names.  The abbreviations are written in the form: 

Botanical nomenclature is universally understood, based on natural relationships among plants, and consistent in form.  It consists of 1) genus and 2) species.  Genus is applied to a closely related group of plants, such as dogwoods or honeysuckle; species is the particular kind of dogwood or honeysuckle.  Place the genus name first, followed by species.

Common names readily identify plants to laymen.  Since a variety of common names can be used for one plant, the preferred names as listed in Hortus III will serve as the standard for HABS documentation.

6.2.5  Information sources for site research:
 

6.3.0  PROCEDURE FOR MEASURING SITES

6.3.1  Small, easily measured sites and larger sites that are relatively flat can be recorded with hand-measuring, triangulation (Figure 6.1) and some work with surveying equipment such as a transit or builder's level.  If base maps exist, they may be used for field noting in addition to new sketches.

6.3.2  A higher degree of accuracy is achieved with a theodolite, alone or in combination with an electronic distance meter (EDM).  These instruments calculate distances and relative heights trigonometrically, virtually eliminating horizontal errors over great distances due to slope, as well as stretching and the catenary effect of tapes held in the air.  Theodolites, EDMs and high-tech laser instruments are usually operated by professionals;  their use will not be discussed in great detail.

6.3.3  Archaeological sites with highly irregular shapes, such as pueblo ruins, are sometimes recorded in plan with aerial over-flight photogrammetry.  A remotely controlled "drone" flies a  special camera over the site.  The series of continuous and overlapping images is read by a CAD system that digitizes the information and draws the plan.  These sites can also be recorded using the above-mentioned surveying techniques.  Wall intersections and other prominent features can be located by angle and distance from a benchmark with an EDM, then relative to each other through triangulation.  Wall thicknesses and room shapes can then be determined. 

6.3.4  If triangulation is undertaken carefully, it can be accurately used to survey a relatively flat site.  The fundamental principle is to locate every unknown point from two other known points.  First, structures are located relative to each other, then trees, roads, walks, utility poles, planting beds etc. are located relative to the nearest structures. 

Figure 6.1: Site triangulation.

6.3.5  To locate a measured structure EFGH from another measured structure ABCD, run a tape from A and B to E, and again from A and B to F.  The tape should be held as taut and level as possible.  EFGH is now placed relative to ABCD. 

6.3.6  Trees are located relative to structures by estimating the center of the tree, or by measuring the diameter and adding the radius (d/2) to a measurement to the nearest side.  The canopy is recorded by laying a tape on the ground out from the trunk.

6.3.7  Structures situated great distances from each other can be located by establishing pairs of intermediate reference points between  them, usually in the form of nails driven into stake.  The stakes should be 10'- 20' apart.  Triangulation can then be continued from these points.  Maintaining tautness and horizontality to ensure accuracy can not be over-emphasized, because small initial errors can be greatly compounded over great distances.

Figure 6.2:  Finding the radius and center point of a curve.

6.3.8  To determine the proper curvature of a street corner or other curved space or object (Figure 6.2), first determine the radius of the curve by using the formula:

where R=radius, c=chord FG, and y=HJ, the distance from the midpoint of the chord to the midpoint of arc GJF.  To form the chord, stretch a tape across the curve, and with a second tape, measure the distance from the midpoint of the chord to the arc at 90 degrees without moving either tape (see also Figure 3.4).  Calculate the radius and locate the center of the curve. 

Perform this operation on at least two chords.  If the located centers do not match up within a reasonable margin of error, the arc is not circular.  To find the diameter of large circular areas in plan, please see the methods outlined in Appendix D: Determining the Heights of Tall Structures with a Transit.

Figure 6.3:  Locating and measuring a water course.

6.3.9  To survey a watercourse, first establish datums from near-by structures or walls (a-b, b-c in Figure 6.3).  Stretch and secure with nails one or a series of tapes along the side of the watercourse closest to the reference structure. Strings divided into the required increments with masking tape and pen marks may also be used, and are preferred if measuring is to take place over more than one day.

Depending on scale and the required accuracy of the drawings, measure out from the tapes--at right angles--every 1, 5 or 10 feet to each side of the water course.  Stones and other features can also be placed in this manner. 
 

6.4.0  PROCEDURE FOR DRAWING PRELIMINARY SITE PLANS

6.4.1  A site plan should be drawn in the order in which it was measured, that is, unknown points found relative to known ones, amorphous features such as plants and stones located relative to dimensionable ones.

1)  Draw the principal structure in plan, taking care to show roof  outlines if they project beyond the building walls;
2)  locate all built structures relative to each other;
3)  locate fences, walls, bollards, etc. relative to the nearest structures;
4)  locate streets, walks and other hardscape;
5)  draw tree trunks and canopies;
6)  draw the remainder of the planting;
7)  add graphic scales, planting lists, north arrows, plant designations, notes.

6.5.0  INKING SITE PLANS

6.5.1  The site plan should include a roof plan and enough detail of the surrounding area to indicate important relationships with nearby structures and landscape features.  If the site itself is the focus of the project, as in the case of a formal garden, for example, the detail and relative line weights should reflect this emphasis.