Chapter 1 | General Background | Chapter 8 | Topographical Surveys - Direct Levelling | |

Chapter 2 | Measuring Horizontal Distances | Chapter 9 | Topographical Plans and Maps | |

Chapter 3 | Measuring Horizontal Angles | Chapter 10 | Measurement of Areas | |

Chapter 4 | Measuring Vertical Angles and Slopes | Chapter 11 | opography and Freshwater Fish Culture | |

Chapter 5 | Measuring Height Differences - PART 1 | Annex 1 | Some Useful Mathematical Formulae for Regular Geometrical Figures | |

Chapter 6 | Measuring Height Differences - PART 2 | Annex 2 | Tangents and Values of Angles | |

Chapter 7 | Topographical Surveys - Plan Surveying | Annex 3 | Cosine Values of Angles |

1.0 What is topography?

1.1 Purpose of this manual

1.2 Why do you need to know about
topography?

Choosing a site

Surveying a site

Making a construction survey

Studying your water supply

Studying your soils

1.3 There are two kinds of lines in
topography

1.4 How to plot lines in the field

1.5 How to make and use markers to
plot your line

1.6 How to set out a straight line
between two points

Setting out a straight line between two points visible from each other

Setting out a straight line between two points when you cannot see one from the other

1.7 How to prolong a line you have marked in the field

How to prolong a line where there is no obstacle

Prolonging a line behind an obstacle

2.0 Introduction

Measuring distances along straight lines

Expressing distances as horizontal measurements

Measuring distances along lines that run through obstacles

Choosing the most suitable method

Calculating perimeter lengths

2.1 How to measure distances with a ruler

Making your own ruler

Measuring short distances with your ruler

2.2 How to measure distances by pacing

Finding your own pace factor

Measuring horizontal distances by pacing

Pacing with a passometer or a pedometer

2.3 How to chain with a rope

Making your own measuring rope

Measuring horizontal distances with a rope

2.4 How to chain with bands or tapes

Measuring horizontal distances with a steel band or a tape

2.5 How to chain with a surveyor's chain

Measuring horizontal distances with a chain

2.6 How to measure distances by chaining

Chaining over horizontal ground

Chaining over sloping ground

Chaining over irregular ground

Improving the accuracy of your chaining

2.7 How to measure distances with a clisimeter

Making your own stadia staff

Measuring distances with a stadia staff

Measuring distances on sloping ground

2.8 How to measure distances by the
stadia method

2.9 How to measure distances that
run through obstacles

Measuring a distance across a lake or an agricultural field

Measuring a distance across a river

3.0 Introduction

What is a horizontal angle?

Expressing horizontal angles

Some general rules about angles

Choosing the most suitable method

3.1 How to use the graphometer

Building your own graphometer

Using the home-made graphometer to measure horizontal angles

Measuring an angle with an inaccessible summit.

Measuring consecutive angles

3.2 How to use a magnetic compass

What is a magnetic compass?

Using the compass to measure horizontal angles

Measuring the azimuth of a line

Measuring a measure horizontal angle

Surveying a polygonal site

Checking when using a compass

3.3 Graphic methods for measuring horizontal angles

Using a simple compass and a protractor in the field

Using a plane-table and a protractor.

What is a protractor

Making your own protractor

Using the protractor to measure an angle you have drawn

3.4 How to measure horizontal
angles by the right-angle method

3.5 How to measure horizontal
angles with a theodolite

3.6 How to set out
right angles or perpendiculars

What are right angles and perpendiculars

What are the main problems you will face

Dropping a perpendicular by the full-circle method

Dropping a perpendicular by the half-circle method

Setting out a perpendicular by the mid-point method

Setting out a perpendicular by the intersection method

Using the short-line intersection method

Using the long-line intersection method

Setting out a perpendicular by the 3:4:5 rule method

Making your own 3:4:5 measuring line

Using the short 3:4:5 line to set out a right angle

Using the medium 3:4:5 line to set out a right angle

Using the long 3:4:5 line to set out a right angle

Using a measuring tape to set out a right angle

Setting out a perpendicular with a cross-staff

Making your own cross-staff

Adjusting the home-made cross-staff

Using the cross-staff to set out a right angle

3.7 How set out parallel lines

What are parallel lines

Setting out parallels by the 3:4:5 rule method

Setting out parallels with the crossing-lines method

Setting out a series of rectangular areas

4.0 Introduction

How to express the slope of a line

Converting percentage of a slope into degrees, or degrees into percentage

Measuring and calculating slopes

Using slope to calculate horizontal distances

Choosing a method to use for measuring slopes

4.1 How to measure with the
home-made clinometer, model 1

4.2 How to measure with the
home-made clinometer, model 2

4.3 How to measure with the
home-made clinometer, model 3

4.4 How to measure with the
home-made clinometer, model 4

4.5 How to use the clisimeter

Using the clisimeter to measure a slope

Using the clisimeter to lay out a slope

4.6 How to use the optical
clinometer

4.7 How to use miscellaneous
levelling devices

4.8 How to set out and check
verticals

Setting out and checking verticals with a plumb-line

Making your own plumb-line

Using a plumb-line to set out a vertical

Checking small verticals with a mason's level

5.0 Introduction

Height differences in fish culture

Types of problems you will be facing

Measuring the height of ground points

Making your own levelling staff

Choosing the best method for measuring height differences

Calculating height differences from slopes

Calculating height differences from vertical angles

Using height differences to calculate horizontal distances

5.1 How to use the straight-edge
level

5.2 How to use the line level

5.3 How to use the flexible-tube
water level

5.4 How to use the T-bone level

5.5 How to use the improved T-bone
level

5.6 How to use the bamboo sighting
level

5.7 How to use the hand level

5.8 How to use the the surveyor's
level and theodolite

6.0 Introduction: contour
levelling methods

6.1 How to use the mason's level

What is a mason's level?

Using a mason's level to check horizontality

6.2 How to use the A-frame level

Making your own A-frame level

Adjusting the A-frame level

Using the A-frame for contouring

6.3 How to use the A-frame and plumb-line level

Making your A-frame and plumb-line level

Adjusting your A-frame and plumb-line level

6.4 How to use the H-frame water level

Making your H-frame water level

Adjusting your H-frame water level

Using your H-frame water level for contouring

6.5 How to use the semi-circular water level

Making your own semi-circular water level

Uing your semi-circular water level for contouring

6.6 How to contour with non-sighting levels

Using the straight-edge level for contouring

Using the line level for contouring

Using the flexible-tube water level for contouring

6.7 How to contour with sighting levels

Using the bamboo sighting level for contouring

Using the hand level for contouring

Using the surveyor's level or the theodolite for contouring

6.8 How to contour with
slope-measuring devices

6.9 How to set graded lines of
slope

Using slope-measuring devices for setting lines of slope

Using sighting levels for setting lines of slope

Using non-sighting levels for setting lines of slope

7.0 Introduction

What is a topographical survey?

What do topographical surveys involve?

Planning your topographical surveys

What are the main methods used in plan surveying?

7.1 How to survey by traversing

What is a traverse?

Which method should be used for traversing?

Choosing the route of a traverse

Surveying an open traverse with a magnetic compass

Adjusting an open traverse

Surveying a closed traverse with a magnetic compass

Adjusting a closed traverse

7.2 How to survey by radiating

What is a radiating survey?

Choosing the observation station

Choosing a method for radiating surveys

Caraying out a radiating plan survey with a magnetic compass

7.3 How to survey by offset

What is an offset?

Surveying by offset

7.4 How to survey by triangulation

What is triangulation?

Using the triangulation method

7.5 How to use the plane-table

What is a plane-table?

Making a very simple plane-table

Making an improved plane-table

Making your own alidade

Using the plane-table

What are the advantages of plane-tabling?

What are the disadvantages of plane-tabling?

Covering the board with drawing paper

Setting up the plane-table

Orienting the plane-table

Plane-tabling methods for reconnaissance surveys

Plane-tabling for plotting details

Measuring horizontal angles by plane-tabling

8.0 Introduction

What are elevation and altitude?

What are the main levelling methods?

What are the kinds of direct levelling?

8.1 How to level by differential

What is differential levelling?

What are backsights and foresights?

Surveying two points with one turning point

Surveying two points using several turning points

Making topographical surveys by straight open traverses

Making topographical surveys by broken open traverses

Checking on levelling errors

Making topographical surveys by closed traverses

Making topographical surveys by the square grid

Making topographical radiating surveys

Combining traversing and composite radiating

Making topographical surveys with non-sighting levels

Making bench-marks for topographical surveys

8.2 How to level by profile

What is the purpose of profile levelling?

What does profile levelling consists of?

Longitudinal profile levelling by radiating

Longitudinal profile levelling by traversing

Cross-section profile levelling

8.3 How to contour

What is a contour?

What is contouring?

What are the main methods for contouring?

Selecting the contouring method

Laying out contours on the ground with a sighting level

Laying out contours with a non-sighting level

Contouring by the indirect method

9.0 Introduction

What are topographical plans and maps?

Starting topographical plans and maps

9.1 How to make scales for plans and maps

What is the scale of a plan or map?

Expressing a scale

Choosing a scale

9.2. How to make a map by plane-tabling

Mapping an open traverse with a plane-table

Mapping an closed traverse with a plane-table

Mapping with a plane-table by radiating

Mapping with a plane-table by triangulation

Mapping with a plane-table by combined methods

9.3 How to map by protractor and
scale

9.4 How to map contours

What is a contour line?

What are the characteristics of contour lines?

Choosing the contour interval of contour lines

Making a contour map

9.5 How to plot longitudinal profiles

Why are longitudinal profiles plotted?

Information from which longitudinal profiles can be plotted

Scales to be used for longitudinal profiles

Plotting profiles from contour maps

Plotting profiles from your own field survey

9.6 How to plot cross-section profiles

Plotting cross-section profiles from contour maps

Plotting cross-section profiles for earth-work estimates

10.1 Introduction

10.2 How to use the strips method
for measuring areas

10.3 How to use the square-grid
method for measuring areas

10.4 How to subdivide the area into
regular geometrical figures

Measuring areas by triangles

Using a base line to subdivide land areas

Subdividing land areas without base lines

10.5 How to measure areas bounded by a curve

11.0 What you have learned

11.1 How to make preliminary
studies from topographical maps

Finding the size of the drainage area and the availability of water for fish culture

Finding the size of the area to be flooded

Obtaining ground profiles from topographical maps

Finding differences in elevation along a stream

Determining the shape of stream valleys

Making a slope map from a topographical map

11.2 How to make a reconnaissance survey of a possible site

Studying the longitudinal profile of the stream valley

Making cross-section profiles of the potential site

Contour-mapping of the potential site

Finding the maximum area of a reservoir

11.3 How to make a feasibility study of a potential site

Estimating the area of the future reservoir

Estimating the volume of the future reservoir

Estimating the volume of an earth dam

Using what you know about topography to install a pumping station

11.4 How to make levelling surveys for fish-farm construction

Staking out a water supply canal for construction

Staking out a pond bottom before construction

ANNEX I - Some useful mathematical formulae for regular geometrical figures

ANNEX II - Tangents and values of angles

ANNEX III - Cosine values of angles