Irrigation Water Management: Training Manual No. 2 - Elements of Topographic Surveying













Table of Contents


FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

a manual prepared jointly
by
C. Brouwer

International Institute
for Land Reclamation and Improvement

and
A. Goffeau
J. Plusjé
M. Heibloem

FAO Land and Water
Development Division

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior permission of the copyright owner. Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to the Director, Publications Division, Food and Agriculture Organization of the United Nations, Via delle Terme di Caracalla, 00100 Rome, Italy.

© FAO 1985

This electronic document has been scanned using optical character recognition (OCR) software and careful manual recorrection. Even if the quality of digitalisation is high, the FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.


Table of Contents


PREFACE

1. ELEMENTARY SURVEYING EQUIPMENT

1.1 Chain and Tape
1.2 Measuring Rod
1.3 Plumb Bob
1.4 Carpenter Level
1.5 Ranging Poles
1.6 Pegs

2. SETTING OUT STRAIGHT LINES

2.1 Definition of a Straight Line
2.2 Placing of Ranging Poles
2.3 Setting out Straight Lines

2.3.1 Setting out straight lines over a short distance
2.3.2 Setting out straight lines over a long distance
2.3.3 Setting out straight lines over a ridge or a hill

3. MEASURING DISTANCES

3.1 Measuring Short Distances
3.2 Measuring Long Distances
3.3 Measuring Distances in Tall Vegetation
3.4 Measuring Horizontal and Vertical Distances in Steep Sloping Areas

4. SETTING OUT RIGHT ANGLES AND PERPENDICULAR LINES

4.1 Setting out Right Angles: the 3-4-5 Method
4.2 Setting out Perpendicular Lines: the Rope Method
4.3 Optical Squares

4.3.1 The single prismatic square

4.3.1.1 Setting out right angles
4.3.1.2 Setting out perpendicular lines

4.3.2 The double prismatic square

4.3.2.1 Setting out right angles
4.3.2.2 Setting out perpendicular lines

5. CALCULATING SURFACE AREAS OF IRREGULAR SHAPED FIELDS

5.1 Example 1
5.2 Example 2

6. HORIZONTAL LINES, SLOPES, CONTOUR LINES AND DIFFERENCES IN ELEVATION

6.1 Boning Rods

6.1.1 Description
6.1.2 Use of boning rods

6.1.2.1 Setting out horizontal lines
6.1.2.2 Setting out slopes

6.2 The N-Frame Level

6.2.1 Description
6.2.2 Testing the N-frame level
6.2.3 Use of the N-frame level

6.2.3.1 Setting out contour lines
6.2.3.2 Setting out slopes

6.3 The Flexible Tube Water Level

6.3.1 Description
6.3.2 Use of the flexible tube water level

6.3.2.1 Setting out contour lines
6.3.2.2 Measuring differences in elevation

6.4 The Hand Level

6.4.1 Description
6.4.2 Use of the hand level

6.4.2.1 Setting out contour lines
6.4.2.2 Measuring differences in elevation