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Institute for Water Quality Studies

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DWAF PRESENTATION STANDARDS FOR GIS USERS


ADAPTED FOR THE INSTITUTE FOR WATER QUALITY STUDIES


4 September 1997
Institute for Water Quality Studies
Private Bag X313
PRETORIA
0001
Tel: (012) 808 0374
Fax: (012) 808 0338
E-mail: SilberbauerM@dwaf.gov.za
Author: Michael Silberbauer
Status of report: ongoing - to be updated as new symbols become available
IWQS Report Number: N/0000/00/000/0596
First issue: June 1996
This issue: September 1997



CONTENTS

INTRODUCTION
MAP LAYOUT GUIDELINES
GENERAL
MAP TITLE
MAP PLACEMENT
North / South Orientation
Identification of Position of Mapped Area
Map Extent
North Arrow and Scale Bar
MAP REFERENCE (LEGEND)
General
Placement of the Reference Elements
Logos
Additional Information
INDEX MAP
INSET MAPS
GENERAL
Coordinates
Scale
North Arrow
GUIDELINES FOR TEXT
GENERAL
TEXT SIZE
TEXT FONT, COLOUR AND CASE
Text Colour and Type
TEXT PLACEMENT
Fixed Features and Point Features
Linear Features
Areal Features
GRAPHICS AND MAP SYMBOLS
GENERAL
SYMBOLSET FILE ORGANISATION
MAP PROJECTIONS
/hri/db/symbol/wateruse.mrk
/hri/db/symbol/hgh.shd
/hri/db/symbol/standard.mrk
/hri/db/symbol/standard.lin
hri/db/symbol/standard.shd
/hri/db/cover/s-africa/lcl_250




INTRODUCTION

Freda Jonck, Werner Wolfer and Ralene Potgieter have produced a guide to GIS users at Head Office on how to present geographic data according to cartographic standards (Presentation Standards for GIS Users: DWAF, 30 May 1995). Two copies of the guide are available in the Whale Tank. In addition, Michael Silberbauer has a copy of Symbols and Abbreviations Used on South African Charts, SAN HO-6, dated 31 March 1995 and produced by Capt. BH Teuteberg, who is a hydrographer in the SA Navy. ISO 6709 is an example of an international standard for GIS, i.e. the standard representation of latitude, longitude and altitude.

The purpose of this adaptation of the Head Office standards is to give specific details relating to water quality mapping and to specify where symbol sets may be found on our GIS. Certain standards used at Head Office may not be applicable at IWQS, and these will be highlighted. The idea of these documents is not to be prescriptive but to encourage uniformity and clarity of style within documents. The person composing a map must carry the intended message across to the reader with the minimum of confusion.

MAP LAYOUT GUIDELINES

GENERAL

Map layouts can be portrait or landscape. When choosing a layout to be used in a report, match the map layout to the text layout and be consistent so that the reader does not have to continually turn the report in order to see figures and text the right way up. The layouts on pages 2 and 3 of the DWAF Guide were developed specifically for Head Office applications, and differ slightly from layouts used at IWQS. The most important differences are the placing of the scale bar, north arrow and logo. The ruled lines for the data block are not normally used at IWQS.

MAP TITLE

The map title should be set in large bold text to stand out from other annotation on the map.

It should be placed in such a way as not to be confused with other map text.

The lettering size can be adjusted to suit the map size and to accommodate long titles.

MAP PLACEMENT

The placement of the map should be such that it does not intrude on the frame, reference, index map and other elements.

North / South Orientation

On manually compiled maps, the orientation of the map may be adjusted to fit the page.

As a general rule, orientation should be north-south with north at the top of the page.

If any other orientation is used, remember to include a north arrow.


portrait map layout landscape map layout



Identification of Position of Mapped Area

There should be enough orientation features to ensure that map readers can see what area has been mapped. Features which are helpful include towns, roads, railways, rivers, coastline and borders.

Map Extent

Information should be shown up to the neatline of the map, except for special cases such as when the boundary of a catchment is used as the edge of the map.

North Arrow and Scale Bar

A north arrow should only be used when absolutely necessary. Many of our maps are produced in Albers projection, and at the eastern and western extremes of South Africa they are 'tilted' away from north.

The north arrow and scale bar should be placed in the empty space at the lower right-hand corner of the map sheet.





MAP REFERENCE (LEGEND)

General

All features on a map must be explained in the reference.

The map reference should be clearly separated from the map.

Placement of the Reference Elements

Align graphics and type correctly, vertically and horizontally.

Group similar items together, e.g. hydrological features, transport lines, land cover types.

Leave enough space between symbols to avoid a cluttered appearance.

Different types of features should be recognizable as such, e.g. area shading or single lines.

Place boxes around area features, but not around point or line features.

Avoid using a zigzag symbol for a line feature - a straight line segment is preferred (this is a problem in ArcView).

Logos

Place logos in the map reference area.

Group multiple logos together.

Avoid reducing logos to such an extent that they are indecipherable.

Additional Information

Include the following information on the map:

Date printed - to write the current date and time use:

text [quote [date -vmsdate] [date -ampm]]

Mapper's name, and optionally the address, phone number, fax, E-mail, etc. (to simplify this operation, place the information in an ASCII file (e.g. address.txt) and write the file with

textalignment left

textfile address.txt block

A reference code, for example the name of a coverage drawn, or the aml that drew it. To automatically write the name of the currently running aml, use

text [quote aml$fullfile].

The projection and parameters, e.g. Albers Equal Area, standard parallels 18S and 32S, central meridian 24E, spheroid Clarke1880. The parameters may be read from the prj or prj.adf file in a coverage, or extracted using describe.

Information sources (can be logos, see /hri/db/clip).

Map number, if any.

INDEX MAP

Separate any index map clearly from the main map.

Use sparse labelling, but sufficient for orientation.

Use a north arrow (if necessary) and a scale bar.

INSET MAPS

Inset maps must be oriented in the same direction as the main map.

They should conform to the style of the main map.

Their position on the main map should be indicated, for example by means of an arrow, box or lines.

Their map features must appear in the main map reference.



GENERAL

Coordinates

Use tics on the map frame or neatline, rather than crosses within the map.

Label tics. If you are using the standard Albers projection ( standard parallels 18S and 32S, central meridian 24E) then inserting the IWQS command chartext near the end of your aml (after map units and page units have been set) will automatically generate a neatline and diced, annotated graticule. For Gauss Conform (LO or Transverse) projection, put the central meridian after the command, e.g. chartext 19.

Scale

In most cases, a scale bar is essential, but don't write the numerical scale (e.g. 1:50 000) unless you are certain that the map will not be scaled up or down during printing.

If a numerical scale is indicated, it should be in the fractional form, e.g. 1:1000 000.

Include 'fine tuning' blocks for a section of the scalebar.

Use a 'rational' subdivision for the scalebar, for example 5, 10, 15, 20 rather than 12.5, 25, 37.5...

The Ultimate Scalebar is a very useful free scalebar AML.

If you work in the Department of Water and Sanitation, a standard aml from Head Office will draw a scale bar with the minimum of fuss:

scalebar automatic %bar% %xt% %yt% width %xm% big_blocks 5 small_block 0 bar_text %xm% scale_text no north_arrow no

where bar is the length, e.g. in kilometres, xt and yt are the page coordinates where the bar should appear and xm is the width of the bar. In amls where the map scale is determined on the fly, the bar length in kilometres needs to be worked out automatically. The following routine is one way of doing this. Put the line &call ScaleBarCalc before the scalebar command.


&routine ScaleBarCalc
&sv mape [show mape]
&sv barxmin [extract 1 %mape%]
&sv barxmax [extract 3 %mape%]
&sv barxlen [round [calc ( %barxmax% - %barxmin% ) / 1000 ]]
&sv barlen [calc %barxlen% * 0.25]
&sv logbar [calc ln %barlen% / ln 10 ]
&sv ilogbar [truncate %logbar%]
&sv flogbar [calc %logbar% - %ilogbar%]
&if %flogbar% < 0.39794 &then
&sv blogbar %ilogbar%
&if %flogbar% >= 0.39794 and %flogbar% < 0.69897 &then
&sv blogbar [calc %ilogbar% + 0.39794]
&if %flogbar% >= 0.69897 &then
&sv blogbar [calc %ilogbar% + 0.69897]
&sv bar [round [calc 10 ** %blogbar%]]
&return




North Arrow

Use a north arrow consistent in size and style with the rest of the map.

Place it above the scale bar and any scale numeral.





GUIDELINES FOR TEXT

GENERAL

Ensure sufficient contrast between the type and the background. Do this by choosing appropriate colours, and placing a mask around the text, if necessary:
textset font
textsymbol 12
textmask rectangle 0.01

Text should not overlap other information. Use the automatic text placement commands if necessary, to space text so that it does not overlap:
overpost 0.05 1.0 0.1
overpost text moveable
overpost on
leaders on
leadersymbol 1
leadertolerance 0.05
textalignment automatic
/* several text commands...
overpost off
leaders off

In general, lettering should be written from the left, parallel to the lines of latitude. This is not easy to do with Arc/Info, so simple left-to-right is sufficient.

If you are doing a manual layout, place the labels for fixed features and those most difficult to arrange first and fit the others in the remaining space.

Writing positioned vertically on the map should read from the lower edge to the upper edge.

Text which at any angle than vertical should read from left to right.

Avoid placing text at an angle of 45.

TEXT SIZE

Use a text size which reflects the size of the object being labelled.

Text smaller than 1.3mm is illegible. The minimum may be larger for wall maps and overheads.

TEXT FONT, COLOUR AND CASE

Be consistent in the use of fonts. Label map features of the same type in the same font. Do not mix fonts without reason. Adjust fonts to suit the size of the map.





Text Colour and Type

Use the following guidelines for labelling features:

Water features - cursive (italics), cyan (light blue) and with Initial Capitals except ocean names which may be all UPPER-CASE.

Towns - non-cursive, black, important towns UPPER-CASE and others with Initial Capitals.

Mountains - non-cursive text spaced along the range, black or brown, UPPER-CASE.

TEXT PLACEMENT

The text for any feature should either be placed entirely over the land surface being mapped, or if relevant, over the ocean. Coastal town names should be placed entirely over the ocean. All text should be placed where it will least obscure underlying information.

Fixed Features and Point Features

If possible, place the names of point features such as towns to the right of the symbol.

The second choice is to the left and the third is 'in close association.'

Text should be placed so that the symbol being annotated does not obscure the lettering.

Linear Features

As a rule, label linear features such as rivers above the feature in such a way that text is read from left to right.

Do not make river names closely follow the curvature of the river, but align them along simple curves.

Keep the words of a long description close together, so that the sense is not lost.

The labels for long mountain ranges may be shown in spaced type but not so far apart that the sense is lost.

Areal Features

If the feature is large enough the label should fall completely within it and be aligned horizontally. An elongated feature that is not horizontal may be labelled parallel to its general orientation. S p a c e d t y p e may be used for large features.

Small areal features should be labelled as for point features.

Label from west to east along the grid lines, if possible.

Annotation for a boundary should be aligned along and within the boundary. Try the command polygonbordertext.

GRAPHICS AND MAP SYMBOLS

GENERAL

These are some general rules for map symbols:

Area features should be large enough so that the reader can match the colouring or hatching with the reference. Detailed coverages displayed at a small, overview scale may have to be generalised to achieve this.

The larger the area being shaded, the lighter the colour (or coarser the hatching) that should be used.

Area shading should not obscure linear elements. Likewise, linear elements should be represented in such a way as to stand out against background shading.

When generalising map information, keep all mapped features at a similar level of generalisation.

SYMBOLSET FILE ORGANISATION

The symbol sets supplied with Arc/Info are available from ArcPlot - simply type a command such as markerset plotter and that markerset becomes the default. A markerset called wateruse.mrk developed at IWQS is also available and contains many useful symbols for mapping water related information. The symbol sets from Head Office described in the DWAF Guide have been copied to the directory /hri/db/symbol with the following names:

hgh.shd - Geological hatched shadeset (hgh.key explains the codes)

standard.lin - Head Office linear symbols

standard.mrk - Head Office point markers

standard.shd - Head Office shade symbols

Use commands of the form shadeset /hri/db/symbol/standard to select these sets.

Note that Arc/Info uses a dual system for storing markers, and if the correct fonts are not present, bizarre effects occur.

Please see the DWAF Guide for an explanation of the symbol tables and the scales at which they are used.

MAP PROJECTIONS

The three most commonly used map projections for southern Africa are listed in the table below. For convenience, many IWQS maps are drawn in Albers Equal Area projection with standard parameters (standard parallels 18S and 32S, central meridian 24E, spheroid Clarke1880). Maps of Lesotho, which were drawn up in Britain, are in the Universal Transverse Mercator projection.



Projection Size of map Typical scale Application
Gauss Conform (Transverse Mercator) <2 wide 1:10 000 Orthophotos
1:50 000 Topographical maps
1:250 000 Topographical maps
1:250 000 Topocadastral maps
Lambert Conform Conic >2 wide 1:500 000 Topographical maps
1:500 000 Administrative maps
1:500 000 Aeronautical maps
1:1 000 000 World aeronautical maps
Albers Equal Area Conic >6 wide 1:1 000 000 Maps of South Africa
1:2 500 000 Maps of southern Africa



/hri/db/symbol/wateruse.mrk (click here for key)
(note that you need to copy the font files (/hri/db/symbol/fnt*) to your local directory for this symbol set to work)

The symbols are in repeating groups of four: the first in each set is black with white masking, the second is red, the third green and the fourth blue. Each symbol is made up of two or more layers, and many effects can be created with the markerlayer, markercolor and markerpen commands.

The first 208 of these markers were developed at IWQS to represent water users and the suitability for use of water in the same symbol. Note that the descriptions given in this key are whimsical, and that you must provide scientifically correct descriptions according to the type of map and the latest guidelines.

Symbols 209 to 220 and 257 to 260 are general-purpose markers.

Symbols 221 to 240 are aquatic weeds, also known as undesirable aquatic macrophytes.

Symbols 241 to 256 are general-purpose ecosystem status symbols, designed to fit inside the rectangles 257 to 260.

Symbols 265 onwards are general purpose map icons.

Further symbols will be added to the set as required. Please submit your requirements to Mike Silberbauer.

/hri/db/symbol/hgh.shd (click here for key)


These symbols were developed for the Water Research Commission's National Groundwater Maps (Water Research Commission Report TT74/95 by Vegter, 1995). They provide a simplified geological classification that can be used as an overlay without obscuring the information on one's base map. The geological classification was developed to highlight those geological features that have bearing on geohydrology.

/hri/db/symbol/standard.mrk (click here for key)

The DWAF Guide symbols for use as point markers. Each marker comes in a group of seven (e.g. 11 to 17 or 461 to 467) ranging from small (1) to large (7) for use at different map scales as in the table below. Note the borehole and hydrological point symbols.



Scale ranges Typical standard scales Symbol number
1:5 000 to 1:13 000 1:5 000

1:7 500

1:10 000

7
1:13 000 to 1:33 000 1:15 000

1:20 000

1:25 000

6
1:33 000 to 1:83 000 1:50 000

1:75 000

5
1:83 000 to 1:183 000 1:100 000

1:150 000

4
1:183 000 to 1:433 000 1:200 000

1:250 000

3
1:433 000 to 1:1 082 000 1:500 000

1:1 000 000

2
> 1:1 082 000 1:2 500 000

1:7 500 000

1



/hri/db/symbol/standard.lin (click here for key)


The DWAF Guide line symbols. Each line symbol comes in a group of seven, e.g. 11 to 17 or 831 to 837, varying from thin (1) to thick (7) for use at varying map scales.

/hri/db/symbol/standard.shd (click here for key)

These shade symbols and patterns from the DWAF Guide are grouped in sets of seven, for use at different scales. Note that shade patterns are notorious for changing colour on different printers, in bright light or on a colour photocopier.

The CSIR and Agricultural Research Council national land cover map uses a different set of symbols to those numbered 714 to 864 here (see /hri/db/cover/s-africa/lcl_250).

/hri/db/cover/s-africa/lcl_250.shd (click here for key)

The files /hri/db/cover/s-africa/lcl_250col.key and /hri/db/cover/s-africa/lcl_250hat.key list the codes used in the CSIR/ARC land cover map of South Africa. Please use these in preference to those in standard.shd.

IWQS queries

IWQS home page.