Farmers and field workers often struggle with complex, expensive land measurement equipment. However, several simple homemade tools can effectively measure level lines, slopes, and contour lines to improve agricultural efficiency. This guide explores practical methods using basic instruments.
I. Using Sight Poles for Level Lines and Slopes
Sight poles are ideal for establishing level lines or lines with constant slopes, particularly useful for canal digging, road construction, and embankment projects.
1. Establishing a Level Line
To create a level line between two reference points (A and B) at the same elevation:
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Step 1: Place intermediate stakes (C, D) between A and B in a straight line.
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Step 2: Align sight poles at A, B, and C by viewing through pole A's top.
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Step 3: Adjust stake C's height until all three poles align horizontally.
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Step 4: Repeat the process for stake D, ensuring all points share the same elevation.
2. Setting Slopes
The process mirrors level line creation, except reference points A and B have different elevations. The slope is calculated using the elevation difference and horizontal distance between points.
II. The N-Frame Level: Contour Lines and Slopes
This simple tool consists of a wooden frame with two legs and crossbars, featuring a carpenter's level fixed to the main board.
1. Calibration
Before use, test the instrument on a level surface. Adjust with shims if the bubble doesn't center between marks.
2. Creating Contour Lines
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Step 1: Place one leg near starting stake (A) and rotate the frame until the bubble centers, marking the next contour point (B).
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Step 2: Repeat the process sequentially across the field to establish the complete contour line.
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Step 3: Adjust stakes slightly for a smooth contour line.
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Step 4: For parallel contours, determine elevation differences (typically 10-50 cm) and repeat the process from new starting points.
3. Setting Slopes
For ditches or furrows with specific slopes (e.g., 1%), shorten one leg proportionally (2 cm for 2m frame at 1% slope). The shortened leg creates the required elevation difference between consecutive points.
III. Hose Level: Contours and Elevation Differences
This tool uses two 2m rulers connected by a 14m transparent hose filled with muddy water, operating on the communicating vessels principle.
1. Establishing Contours
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Step 1: Mark water levels on back-to-back rulers at the starting point.
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Step 2: Move one ruler along the suspected contour until water levels match, marking new contour points.
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Step 3: Repeat sequentially, ensuring no water spills during transport.
2. Measuring Elevation Differences
For points within 10m, subtract ruler readings at both locations. For longer distances, use intermediate stakes and sum sequential measurements.
IV. Hand Level: Simple Contouring and Elevation Measurement
This compact tool features a viewing tube with crosshairs and an attached carpenter's level, typically mounted on a forked stake for stability.
1. Creating Contours
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Step 1: Place the leveled instrument at the starting point.
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Step 2: Mark a ranging rod at the instrument's sightline height.
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Step 3: Move the rod along the suspected contour until the mark aligns with the crosshair.
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Step 4: Repeat the process sequentially (effective within 15m distances).
2. Elevation Measurement
For points within 25m, take back and front readings with a graduated rod and subtract. For longer distances, use intermediate points and sum sequential measurements.
These simple techniques demonstrate how basic tools can effectively replace expensive equipment for essential agricultural measurements.
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