RN-19 : Comparative study of self-recording raingauges

Abstract

Measurement of precipitation with gauges dates back to more than 2000 years. With the development of civilization and science, the demand for intensity of precipitation and its distribution in time has increased. Recording raingauges are used to keep a continuous record of rainfall amount against time. Three types of precipitation recorders are in general use:

i) the float type

ii) the tilting or tipping bucket type and

iii) the weighing type

In India, the float type natural syphon recording raingauge is widely used by the India Meteorological Department (IMD) and state organisations. The tipping bucket type raingauges have been used by IMD for developing Radio reporting raingauges. IMD has also made some further developments in the recording raingauges by developing a high resolution electronic rainfall intensity recorder.

Very few comparative studies of self recording raingauges were reported in literature. Most of the studies reported related to comparison of the recording raingauges with the standard non-recording raingauge.

The vibrating wire strain gauge developed by the Norwegian Geotechnical Institute is found to be a reliable measuring and recording instrument especially in view of its capability for use at long distances upto 1 kilometre away without loss of any information.

It would be necessary to make comparative studies of recording raingauges at selected observatories in India using the float type syphon recording raingauge, the tipping bucket type recording gauge and the weighing type so that the results from these studies could be extended for use in the field with the relatively less expensive float type and tipping bucket type recording raingauges.