Ermelo Topographic Map Study

Vocabulary and key concepts derived from the Ermelo 2629DB topographic map extract and related geography notes.

2629DB Ermelo

The specific map reference and location name for the topographic extract provided.

Mean magnetic declination

The angular difference between True North and Magnetic North, recorded as $18^° 34'$ West of True North in October 2013.

Mean annual change

The rate at which the magnetic declination moves, which was $4'$ Westwards between October 2013 and September 2014.

Contour Interval

The vertical distance between contour lines on the map, which is set at $5\,\text{m}$.

Trigonometrical Station

A surveyed reference point used for determining positions and heights on a map, such as the one found in block A4.

Pivot farming

An agricultural method identified on the map by circular conventional signs used by farmers in the area.

Perennial River

A river that contains water throughout the entire year, represented by a continuous blue line.

Non-perennial Water

Water sources, such as rivers or pans, that do not flow or contain water year-round.

Bench Mark

A surveying symbol on the map used to indicate a precise elevation point at a specific location.

Built-up Area

A geographic classification for regions with concentrated buildings, categorized into High and Low Density.

Marsh and Vlei

Conventional symbols representing wetland areas that are often seasonally or permanently saturated.

Cultivated Land

Map areas designated for the growing of crops, distinguished from orchards or vineyards.

Mean annual change direction

The direction in which the magnetic declination shifts each year, specified as Westwards for this map.

Dry Pan

A natural depression in the ground that is characterized by the absence of water for most of the year.

Arterial Route

A major road classification shown in the map reference, distinct from National Freeways and Main Roads.