The Rise Fall Method Surveying Level Book is a practical and reliable way to record levelling work. In this guide I explain the rise fall method step by step, how to keep a clear level book, and how to do an effective error check.
Use this simple guide for field work, training, or as a quick reference for level book arithmetic check and error distribution rules. The tone is plain and practical so you can apply these ideas right away.
What is the Rise and Fall Method?
The rise and fall method records the change in height between consecutive stations. It is easy to check on paper and works well for most site levelling tasks.
Below are the basic ideas before we go into details and examples.
Basic principle
Measure backsight (BS) and foresight (FS) at each station. The difference gives a rise or a fall. A positive number is a rise. A negative number is a fall.
Why choose this method
- Simple arithmetic checks.
- Good traceability in a level book.
- Easy to spot mistakes and distribute errors.
Level Book Layout and Tools
Before starting, set up a clear level book. Use consistent column headings and neat numbers. A good book makes checks fast and reduces mistakes.
Common columns in a level book
- Station name or mark
- Backsight (BS)
- Foresight (FS)
- Rise / Fall
- Reduced Level (RL)
- Remarks or instrument height if needed
Tools you need
- Automatic level or dumpy level
- Staff (leveling rod)
- Clear level book and pencil
- Calculator for quick checks
How to Fill the Level Book
Follow a simple, repeatable routine. Below are short steps to record a run using the rise fall method surveying guide.
Step-by-step recording
- Start with a known reduced level (RL) for your first point.
- Set up instrument and take a BS reading on the known point.
- Take FS and intermediate readings as you move along.
- Calculate rise or fall for each change: Rise = BS – FS (if positive), Fall if negative.
- Compute new RL: New RL = Previous RL + Rise (or – Fall).
- Record each BS, FS, rise/fall, and new RL neatly in the level book.
Example entries
Use the table below as a simple template and example. This shows a short run and the arithmetic check at the end.
| Station | BS | FS | Rise / Fall | RL |
| Benchmark | — | — | — | 100.000 |
| A | 1.500 | 0.800 | +0.700 | 100.700 |
| B | — | 1.200 | -0.500 | 100.200 |
| C | 1.000 | — | +1.000 | 101.200 |
| Totals | 3.500 | 3.200 | Rises 1.700 / Falls 1.200 | Final RL 101.200 |
Arithmetic Check and Error Distribution Rules
Do an arithmetic check after the run. The rise fall method allows a clear check using sums of rises and falls.
Keep checks simple so you can find mistakes quickly.
Arithmetic check rule
Use this rule: Final RL = Initial RL + Sum of Rises – Sum of Falls. If the numbers do not match, review entries.
How to find small errors
- Re-check BS and FS readings for suspicious rows.
- Verify signs on rise or fall values.
- Confirm the initial RL value.
- If many small errors remain, apply a proportional error distribution across readings.
Error distribution rules (simple)
When small unavoidable error remains, distribute it by station count or by distance. Common approaches:
- Equal share: divide error by number of points and adjust each RL slightly.
- Weighted share: adjust by the length or importance of each line.
Record any adjustments clearly in the level book under remarks.
Practical Application Tips
Field practice makes the method fast and reliable. The following tips save time and avoid rework.
Field tips
- Write neatly and use consistent units.
- Cross-check critical readings immediately.
- Keep a backup run if terrain is tricky.
- Mark stations physically so you can return later.
Common mistakes to avoid
- Mixing up BS and FS columns.
- Forgetting the sign on rise/fall.
- Using wrong initial RL.
- Poor penmanship that hides numbers.
Rise Fall Method Surveying Detailed Guide Notes
This section highlights a few detailed points from the rise fall method surveying detailed guide and level book arithmetic check practices.
Recording intermediate sights
Record intermediate sights as FS when moving forward. Treat them equally in the rise/fall calculation.
Handling backsights often
Take BS on a stable point after each setup. This reduces cumulative error. Note the instrument height in remarks if needed.
Frequently Asked Questions
What is the main advantage of the rise and fall method?
The main advantage is clarity for checks. The method lets you add rises and subtract falls. It also makes it easy to find where an error occurred in the level book.
How do I perform the arithmetic check for a long run?
Sum all rises and sum all falls. Then apply Final RL = Initial RL + Sum(rises) – Sum(falls). If you have a mismatch, check rows and BS/FS signs. Use error distribution only for very small residuals.
Conclusion
The rise fall method surveying level book approach is simple, reliable, and easy to check. Keep your entries neat. Use the arithmetic check and sensible error distribution rules. With practice you will make fewer mistakes and finish levelling tasks faster.
