Question

Which of the following raingauge records the cumulative precipitation?

• A. Symon's
• B. Tipping Bucket
• C. Float type
• D. Weighing type

Hint:

Mass Curve of Rainfall:
- The plot of cumulative rainfall vs. time is called the Mass Curve.
- The Weighing bucket and Natural Siphon (Float) types are the primary instruments used to generate this curve.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Rain gauges are instruments used to measure the depth of precipitation.
They are classified into non-recording types (which only measure total rainfall over a period) and recording types (which continuously record rainfall intensity and accumulation over time).

Step 2: Detailed Explanation:
Let us analyze the functions of the different rain gauges:
- Symon's Rain Gauge: It is the standard non-recording rain gauge used in India.
It does not record rainfall continuously; it must be manually measured at set intervals (usually daily).
- Weighing Bucket Type Rain Gauge: In this recording gauge, the falling rain is collected in a bucket placed on a weighing scale.
The increase in the weight of the bucket is continuously transmitted to a pen that plots a curve on a clock-driven chart.
This curve directly represents the cumulative precipitation over time, also known as the mass curve of rainfall.
- Tipping Bucket Type Rain Gauge: It consists of a pair of buckets that tip when a pre-determined depth of rain (typically \(0.25 \text{ mm}\)) accumulates in one.
This is suitable for recording rainfall intensity rather than direct cumulative curves.
- Natural Siphon (Float) Type Rain Gauge: It uses a float that rises as water enters.
While it also plots a cumulative curve, the weighing bucket type is the classic and most direct method defined for recording cumulative precipitation on a weight basis.

Step 3: Final Answer:
The rain gauge that records cumulative precipitation directly on a weight basis is the Weighing type.