contour lines

they are imaginary lines connecting places at the same height above mean sea level.

what is a contour interval

it is the interval at which the contour lines are drawn.

how to find contour interval

if the height difference of 2 contours is 20 m, the contour interval will also be 20 m.

what is index contour

it is a thick brown contour drawn at every 100 m used to calculate the height.

spot height

it is the exact vertical distance of the elevated part from sea level. it is marked in metres above sea level.

how can you make contour lines if spot height is given

by connecting places with same spot height with contour lines

what are the methods of representing height

benchmark, spot height, trigonometrical station, contour lines

benchmark [if height is 10 m]

BM 10

spot height [if height is 10 m]

.10

trigonometrical station [if height is 10 m]

Δ 10

contour lines [if height is 10 m]

contour line symbol with 10 in it

easiest way to draw relief using a contour map

using cross-sections.c

cliff

contour lines meet together

gentle slope

contour lines are far apart

steep slope

contour lines are close together

conical hill

Contour lines appear in concentric circles with even spacing. The innermost contour line has the greatest value, and the slopes are equal in all directions.

plateau

The innermost contour line may be wide to represent the table-like nature of the plateau, and the edges may be close to depict steep slopes.

ridge

It is a long, narrow, sharp-edged upland with several peaks. The contours may be either closely spaced or widely spaced.

col

the lowest point on a mountain ridge between two mountain peaks. it can be identified as narrow gap between ridges.

saddle

It is a shallow depression between 2 hills. It is a broader gap than col.

gap

it is a low depression close to the ground.

pass

it is a gap between 2 hills at a higher elevation. it is used for transport and trade.

linear settlements

1. it noticed along a railway line, river, or metalled road. 2. it is usually created because of the transport and trade advantages.

nucleated settlements

1. it is found in areas with too many opportunities. 2. it has economic prosperity 3. they are major villages, cities, or towns or found in places with difficult terrain where favourable conditions are agglomerated at one point.

dispersed settlements

1. it is found in large farms with a few residents 2. seen in remote areas

eastings

north south running lines

northings

east west running lines

starting point for measurement

the extreme southwest grid is the reference point.

order of grid reference

eastings then northings

types of grid references

four digit and six digit

four figure grid reference

it is used to locate places falling within a grid square. the first 2 digits are eastings and last 2 are northings.

six figure grid reference

it is used to locate objects with greater accuracy within the grid. first 3 digits are eastings, last 3 digits are northings.