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close this book Forestry training manual Inter-America Region
View the document Information collection & exchange
View the document Acknowledgements
View the document Trainer guidelines
Open this folder and view contents Training program overview
View the document Forestry observation guide for site visit
Open this folder and view contents Getting ready
View the document Conducting the training program
View the document Weekly evaluation form
View the document Session I day one
View the document Daily schedule for technical training
View the document Session II special projects
View the document Session III The forest of the world, peace corps forestry goals, the individual volunteers' roles
View the document Session IV Language class
View the document Session V Exercise I: Record keeping
View the document Session VI Exercise II
View the document Session VII Flowers, seeds, the beginning
View the document Session VIII Spanish language class
View the document Session IX Non-verbal communication
View the document Session X Basic site selection, planning and layout of a nursery
View the document Session XI Spanish language class
View the document Session XII Cultural values
View the document Session XIII Soil preparation, seed bed sowing, and reproduction by clippings
View the document Session XIV Spanish language
View the document Session XV Communication through illustration
View the document Session XVI Fertilizers, watering and containers
View the document Session XVII Spanish language
View the document Session XVIII Protection and record keeping
View the document Session XIX Individual interviews
View the document Session XX Planting trees
View the document Session XXI Spanish language session
View the document Session XXII Introduction to extension
View the document Session XXIII The principals of pruning and thinning
View the document Session XXIV Spanish language
View the document Session XXV Volunteer's role as an extensionist
View the document Session XXVI Pacing, plane table, rustic transit and compass
View the document Session XXVIII Spanish language
View the document Session XVIII Forestry extension
View the document Session XXIX Forest menstruation
View the document Session XXX Spanish language
Open this folder and view contents Session XXXI Working with groups as an extension worker
View the document Session XXXIII Spanish language
View the document Session XXXIV Lesson plan and use of visual aids in teaching
View the document Session XXV Small research projects
View the document Session XXXVI Individual interviews
View the document Session XXXVII Soils
View the document Session XXXVIII Spanish language
View the document Session XXXIX Community analysis introduction
View the document Session XL Soil erosion
View the document Session XLI Spanish language
View the document Session XLIII Watershed management
View the document Session XLIV Spanish language
View the document Session XLV Review of expectations - mid way
View the document Session XLVI Spanish language
View the document Session XLVII Species report
Open this folder and view contents Session XLVIII Forestry issues
View the document Session XLIX Spanish language
View the document Session L Field trip overview
View the document Session LI Ecology teams give presentations
View the document Session LII Individual interviews
View the document Session LIII Review of field trips
View the document Session LIV Project planning: goal setting
View the document Session LV Spanish language
View the document Session LVI Resources
View the document Session LVII Compost heap - insect collection - light gaps
View the document Session LVIII Spanish language
View the document Session LIX Cultural shock - are we ready for it?
View the document Session LX Grafting and fruit trees
View the document Session LXI Spanish language
View the document Session LXII Professional approaches to interaction with host country officials
View the document Session LXIII Final interviews
View the document Session LXIV Graduation

Session XXVI Pacing, plane table, rustic transit and compass

Total Time: 4 1/2 hours

Goals:

- Learn how to use a plane table.

- Learn how to use rustic level.

- Learn how to pace.

- Learn how to use a compass.

- Learn how to make a simple traverse.

- Learn simple method for calculating area. Overview

In this session trainees learn several forestry techniques. Trainees will demonstrate special projects they have completed;

i.e., plane table and rustic transit. Participants learn how to pace, how to make a simple traverse and how to calcuate area.

Exercises:

1. plane table

2. rustic level

3. pacing

4. compass use

5. simple traverse

6. simple calculation

Materials:

1. Plane table (made by trainee),

2. Rustic transit level (made by trainee),

3. Compass (you will want to ask anyone who has a compass to bring it to the session),

4. Two (2) meter long sticks for trainees,

5. Bright colored flagging (surveyor's plastic flagging),

6. graph paper.

Exercise I Plane Table Survey

Total Time: one half hour

Overview

Quite often, Peace Corps volunteers are called upon to assist in or draw a map of an area. Sometimes sophisticated surveying equipment is not available or the volunteer does not understand how to use it. One solution to this problem is the plane table survey. This is a simple method of mapping an area utilizing a plane table, graph paper, common pins and a rubber band. On day one a participant undertook this project for demonstration. Here in this exercise the plane table method is demonstrated and participants learn its use.

Procedures

Time

Activities

 

1. Trainee introduces his special project to group. Demonstrates its use. (Sample follows)

 

2. Trainees will later in this session practice using plane table.

PLANE TABLE SURVEYING

Quite often, Peace Corps volunteers are called upon to assist or draw up a map of a certain area. Sometimes, sophisticated surveying equipment is either not available or the volunteer does not understand how to use it.

As a solution to this problem a plane survey table (fig.16) can be used. This is a simple method of mapping an area utilizing a plane table, graph paper, common pins and a rubber band.

The paper is laid on the table. Next the table is placed on one of the corners of the area to be surveyed. After leveling the table (you can use a small inexpensive carpenter's level), stick a pin in the paper in the corner corresponding to the corner of the traverse where you are (i.e., SW corner of traverse corresponds to the bottom left of your paper).

Next take another pin and using the first pin as the backlight, line the second pin up with the next corner of the traverse. To determine the distance, you can either pace the distance or use a measuring tape. Using a scale (1 cm = 10 m) draw the line between the pins and you have your first leg of the traverse. (fig. 18)

Next go to the corner which you just measured and set up the plane table there (do not forget to level the table). Line up both pins so that the line of sight through these pins is the line you just measured. Then turn and using the pin for the point where you are as the backlight, line up another pin to the point to the next corner, turning point). You would repeat this process at every corner of your survey until you've completed the traverse,

Any buildings or other points within the traverse could be included by "shooting" a line to each corner of the building using the method described above.

With this process you actually draw the map as you go along and you need not rely on a compass for your work.

Once you have the map completed, you can determine the area in one of two ways. First, if you used graph paper, you could count the blocks to determine the area (if you drew the map to scale you could determine the area in one block of the graph paper).

The second method would be geometrically (fig. 19). You break the figure down to simple figures such as rectangles and right triangles and then determine the areas for each using the formulas:

Area of a rectangle = length X width

Area of a right triangle = 1/2 base X height

Plane Table Surveying

The advantages of a plane table are:

1. Easy to build

2. Easy to use

3. A cheap system to determine area

The possible disadvantages could be:

1. Could be heavy and cumbersome

2. Wouldn't be as accurate as a transit

3. Weather could play a determining role (i.e., rain)

With the materials available virtually throughout all the developing nations of the world and the cost so low, there is no reason why with some practice, we could not be able to map an area of land if called upon to do so.


PLANE SURVEYING TABLE

PLANS SURVEYING TABLE


Fig. 18

1. Pins

2. Line of Sight (fey of traverse)


Fig. 19

Area of right triangle = 1/2 bh

Area of rectangle = 1 X w

Exercise II Rustic Level (Ceuvas de nivel)

Total Time: one half hour

Overview

Planting along the contour is an agricultural practice used in erosion control. Rustic instruments can be constructed easily and cheaply. In this exercise, one such instrument, the rustic level is demonstrated.

Procedures

Time

Activities

 

1. Trainee(s) introduces special project to group. Demonstrates its use (sample follows).

1/2 hour

2. Trainees will later in this session, practice using a rustic level.

RUSTIC LEVEL FOR CURVAS DE NIVEL


Fig. 20

Demonstration on Curvas de Nivel as de Nivel

Here are the materials necessary for construction of this rustic level. Its uses are for designing contour terracing for soil erosion control and other land surveys.

Materials

- Board 4 cm (h) X3 cm (w) X2 cm (1)

- Pole 2m long (bamboo is good for this)

- Small piece of wood 2 cm (h) X 4 cm (w) X 40 cm (1)

- 1 wing nut, 6 cm long

- Nails

- 1 protractor

- 1 plumb line

- 1 weight (bowling ball is too big)

- A piece of cloth - marker

- Bottle cap - sight

- Stakes for surveying

CURVAS DE NIVEL

The term "Curves de nivel" is translated into English to mean contour lines. Plowing along the contour is an agricultural practice to aid in erosion control. By plowing with the contour, soil erosion can be reduced by as much as 50%. "Curves de nivel" are generally incorporated with other erosion control measures such as strip cropping, crop rotation, agroforestry, diversion ditches and diversion terracing.

Diversion terraces are a widely used method in South America to catch surface runoff and allow its safe exit from the field. The terraces are constructed along the contour at intervals down the slope. The distance between terraces varies depending on the slope of the land. The terrace is raised to a height of 50 - 70 cm with a width of 1 meter. The up slope side of the terrace has a channel 50cm wide and 30cm deep which catches surface runoff. This channel has a gradual slope of 0.25 - 0.50 percent off one side of the field. The channel should be covered with a low growing grass to reduce erosion in the channel itself. The terraces should be vegetated also with bunch grass, trees or left for natural weed cover to take over.

Curvas de nivel can be rayed out using rustic or modern instruments. Rustic instruments can be constructed easily and cheaply. Three people are generally needed to lay out the contour lines. Using rustic methods, about 4 - 6 ha/day can be marked as opposed to 15 - 20 ha/day with a tripod surveyers level. These figures vary depending on the uniformity and slope of the land.

Laying out the "Curves de Nivel l) The first step is to measure the slope of the field in degrees or percent. The steepness of the slope will determine the distance between terraces. The steeper your slope the closer your terraces, the less your gradient the farther apart the terraces. Slope can be measured using a protractor, abney level or purveyers level. The protractor will give degree slope while the latter will be two percent slope. Tables are available in most areas which indicate terrace spacing in relation to slope and soil type.

2) After determining slope and the terrace spacing the marking can be started. Start from the highest point in the field and measure down the slope of your calculated terrace interval to your first point. It is important to always measure this distance directly down the slope. This direction may not coincide down the border of the field. If this distance is not measured directly down the slope, your terraces will not have uniform distances between them. This may mean starting from the middle of the field (fig. 1) from point "A" and measuring down slope towards point "B". Point "B" is the starting point. From here you mark the contour towards the borders of the field.

When you arrive at point "C", you measure to your next terrace to point "D", directly down slope.


Fig. 21

Using the rustic instruments, points can be Marked every 10 or 15 meters. The points are marked by driving a stake into the ground. Using a surveyor, level points can be placed every 30 - 35 meters. A helpful way to measure these distances is to tie a light weight rope between the sighting instrument and the sight rod.

Once all the contours are marked you will see that some stakes may not be in line. It will be necessary to adjust some points in order to have a smooth plow line. For example a sharp V in the contour will cause water to collect and leak through the terrace. It will also be harder for the farmer to plow his field.

3) The terraces can be constructed with tractor, horse, oxen or hand. The tractor is most efficient because it can throw more soil. When using animals, it is necessary to follow up with hoes to raise the terrace and also deepen the channel in front.

The actual plowing is done by throwing soil toward the stakes on both the uphill and downhill side. With a tractor two passes on each side is usually sufficient. With animals 3 - 4 passes on each side are recommended. With either method the last pass should be on the uphill side to clean out the diversion channel.

4) Vegetation should be established as soon a possible. Bunch grasses can be planted from cuttings or by seed. The grass in the diversion channel can be seeded or left to natural weeds growth. Trees can also be planted on the terraces in conjunction with the bunch grasses.

SOME WAYS TO USE YOUR RUSTIC TRANSIT

Mostly you will be using this level to aid you in making contour level terraces (curves de nivel). These are for the protection of soil in crop fields. This method is not recommended for over 13% slope.

Example: This is a Curva de Nivel


Fig. 22

You take your rustic transit (transito rustic) and sight out over your sight arm to the mark on the sight pole (which is 10 meters away in this example).


Fig. 23

You have the man move up or down the slope until you see your mark through the sight. Then he puts a stake in that spot, and then its on to the next mark. Fairly soon, you would have stakes all along the contour of the slope for that particular terrace (curvas).


Fig. 24


Fig. 25

All of these are 10 meters apart.

You want to make an average line out of these stake markers because it would be too hard to work, and puddles of water would gather in the pockets.

MIRA


Fig. 26

RUSTIC LEVEL ( MAQUINA )


Fig. 27

Some ways to use you rustic transit

Also you can incorporate a drainage slope in your curves de nivel. This would be to disperse water caught in the ditch of the curves de nivel. For example, you decide on .5% slope for drainage. For every 1% slope at 10 meters distance from sight pole to rustic level you move your mark on sight pole up or down (depending which way slope will run). In this case, with .5% slope drainage at 10 meters distance you would move mark up or down 5cm.


Fig. 28

For .5% slope, drain off channel, move sight line 5cm every 10 meters between the two men (up or down depending on which way you want water to run), towards sight man or "maquina" man.

You can control 50% of your erosion, just by running your rows of crops along the contour line which does not need to be long.

The following Peace Corps Volunteers contributed to this exercise: Michelle Myers, Jacob Fillion and Jim Storandt.

Exercise III

Pacing

Total Time: one half hour

Overview

Pacing, if done correctly can be used to yet good distance measurements. Technical trainer instructs trainee in method of pacing and how to measure distance by pacing.

Procedures

Time

Activities

15 minutes

1. Technical trainer gives lecture on pacing and gives instructions in the use of a pacing stick (post on newsprint).

15 minutes

2. Trainees figure out their pace and make pacing stick for themselves.

Objectives: To teach trainees how to measure distance by pacing.

Pacing

Pacing if done correctly can be used to yet good distance measurements.

Methods for developing pacing skills:

1. Lay out a base line 20 meters long.

2. Walk naturally along base line to determine how many paces you take for 20 meters (1 pace=2 steps).


Fig. 29

3. Cut a stick the length of your pace.

4. On flat ground you can pace naturally keeping track of every 20 meter interval.

5. On slopes you can use your stick to measure your horizontal pace.


Fig. 30

Pacing Examples

1. My pace: (2 steps) = 1.6 meters.

(My stick is 1.6 meters long).

2. My pace for the 20 meter baseline = 12.5 paces.

3. 62.5 paces = 100 meters.

Trainer's Note: Although pacing is not widely used in the U.S., it is desirable for PCVs to know this method for use in developing countries and to be able to teach the same.

4. When actually pacing off an unknown distance, put out a finger, or pick up a stone or stick to keep track of every 20 meter segment. Total distance can easily be calculated in your head.

Example:

At the end of an unknown segment I have 3 stones in my hand and 4 paces more.

3 X 20 meters = 60 meters 4 X

1.6 approx equals 4 X

1.5 = 6 meters

Total Distance = 66 meters

Exercise IV

Compass

Total Time: one half hour

Overview

Some of the participants will not have been instructed in the use of the compass. Those who know how to use a compass will assist other trainees in learning its use.

Procedures

Time

Activities

15 minutes

1. Trainer lectures on use of compass. On newsprint, show the Azimuth compass, Quardrant compass and the European compass and their use.

15 minutes

2. Trainees who do not know how to use compasses practice aided by trainee who knows how to use them.


Fig 31


Fig 32


Fig 33


Fig 34


Fig. 35

Exercise V

Simple Traverse

Total Time: 1 hour

Overview

This exercise gives trainees a chance to use pacing skills and compass to run a simple traverse.

Procedures

Time

Activities

 

1. Prior to this session, forester trainer stakes out an area on which trainees practice. Forester trainer uses flags to mark points. The area selected should have some steep slopes.

 

2. Trainees are divided into groups with at least one forester trainee in each group.

 

3. They go out and run a traverse using hand compass and pacing.

 

4. Upon completion of traverse, trainees plot the area on graph paper an calculate the area.


(Fig. 36)

Exercise VI

Simple Calculations

Total Time: 1 hour

Overview

To teach trainees a simple method of determining approximate land areas is the objective of this exercise.

Procedures

Time

Activities

 

1. Forester trainer gives lecture on area calculation and posts the following on newsprint.

   

1.1 plot out traverse to scale on sheet,

   

1.2 break down traversed figure into right triangles and/or rectangles,

   

1.3 calculate each area in right triangle and/or rectangle,

   

1.4 total all calculations,

   

1.5 divide by 10,000 to get hectares,

 

Area Formulas

 

Area of right triangle = 1/2 (hase)(height)

 

Area of rectangle = (hase)(height)

   

1.6 can check by counting squares on graph paper.

 

2. Forester trainer continues with lecture on area traverse record keeping. Displays the following example.

CALCULATING AREA BY BREAKING AREA FIGURE INTO RIGHT TRIANGLES


Fig. 37

Area Traverse


Area Traverse

Field Sketch

Hypothetical Data Sheet

Date: November 18, 1981 weather: Clear Crew: Joan Gonzales

Peter PCV

Pedro Garcia roofs: Hand Compass & Pacing


(Fig. 38)
 

3. In the small groups which trainees have worked during this session, they go out and practice the use of a plane table and rustic transit.

 

4. Forester trainer checks each group's area map, calculations and traverse.

Trainer's Note: While forester trainer works with one group at a time the other groups use plane table and rustic transit. This gives everyone time to practice. This is also a time to observe ho`' well forester trainees are able to transfer skills, explain, have patience etc., with generalist trainees. Record these observations because you will want to give forester trainees feedback during interview on their performance.