Methods of representing physiographic features

WELCOME

METHODS OF REPRESENTING

PHYSIOGRAPHICAL FEATURES.

Physiographic refers to the difference in height between the highest and lowest land surface in a locality of nature.

Physiographic [or terrain] is an essential aspect in physical geology.

INTRODUCTION

Topographical maps they show a great deal of details about the physiographic features.

INTRODUCTION

PHYSIOGRAPHIC FEATURES

Methods used to represent features are based on this two. 1.ISOPLETH,2.CHOROPLETH.

TYPES OF METHODS TO REPRESENT FEATURES ARE;

Isopleths are lines joining places of equal value ,this value may be in form of quantity , intensity or density.

Following are few examples of isopleths,

1.ISOPLETH

1. Isobar – Equal pressure,2. Isotherms– Equal

temperature,3. Isohyet – Equal rainfall,4. Isohaline – Equal salinity.Isopleth maps are also require a large amount of data for accurate drawing.

1.ISOPLETH

1.ISOPLETH

In this method areas are shaded or patterned in proportion to the measurement of statistical variable being displayed on the map.

2.CHOROPLETH

The choropleth map provides an easy way to visualize how a measurement varies across a geographic area or it shows the level of variable within a region.

2.CHOROPLETH

2.CHOROPLETH

It is used to show surface features on the map.

Hachures are short lines of varying thickness to show the shape and slope of land.

In accordance with this technique, the steeper slope is represented by thicker lines.

A. HACHURING

They do not represent exact elevations but are mainly used to show large rocky outcrops.

It is one type of isopleth method.

A. HACHURING

A. HACHURING

Hachuring was replaced with a scientific form of hill shading and spot heights.

Hill shading resembles a light and shadow effect.

Valleys and the sides of mountains appear as that they are cast in shadow.

B. HILL SHADING

It is visually striking method.However does not show height which means that it is no more accurate like contours.

It is a choropleth method.

B. HILL SHADING

B. HILL SHADING

Contour lines are lines that connect points (spot height) that are the same height reference to MSL.

They accurately depict the height, shape, slope of a landscape.

The numbers which are featured on each line represent the exact height on the land at points along that lines.

C. CONTOUR LINES

The patterns created by the line show the shape of the land.

The slope an also be identified by using contour lines.

The closer contour lines represent the steeper slope.

The gentle spaced contour lines represent the gentle slopes.

C. CONTOUR LINES

Contour interval: It is the difference in the height

between the contour lines.Contour interval may be in 20m,

50m, 100m…

C. CONTOUR LINES

C. CONTOUR LINES

C. CONTOUR LINES

They are used to show the exact height of the land at a particular point.

They are depicted using a dot (or triangle) and a corresponding number, which represent altitude at that point.

They do not provide much information about the shape of the land.

It is reference for isopleth methods.

D. SPOT HEIGHT

D. SPOT HEIGHT

Layer tinting uses different colors (or shades) to represent different heights.

A different color is used for each band of elevation.

Each shade of color or band represent a definite elevation range.

E. LAYER TINTING

A legend is printed in map to indicate the elevation range represented by color.

However, this method does not allow the map user to determine the exact elevation of a specific point-only the range.

E. LAYER TINTING

E. LAYER TINTING

Physical geology – Judson. Kauffman. Leet

Map work and practical geography by Govind Singh,

www.rmlau.ac.in/julgo22.pdf,https://en.wikipedia.org/wiki/choropleth_

map,

REFERENCE:

THANK YOUBY,

A TEAM