TN-43 : Instrumentation for snow measurement

Abstract

Reliable measurement of snowfall and estimation of snow cover is important for estimation of snowmelt. Unlike in the other countries where the areas of snowfall and accumulation are easily accessible, in India the rugged terrain and mountains do not permit continuous observation of the snow and related data by manual means. There is, therefore, need for automation of measurement. Also, the measurement of' snow by conventional snow gauges is prone to errors due to drifting snow, under catch due to wind etc.

In this technical note, the technical a4pects of various types of snow gauges and other techniques for estimation of snow cover have been reviewed with a view to examine their utility and applicability for snow measurement in the Himalayan Catchments. The review has indicated several new types of instruments which can continuously sense and record the snowfall and its water equivalent. The effect of various shields on improving the catch efficiency is also discussed.

The reliability, accuracy, design and maintenance of the instruments have also been discussed. It has been suggested that existing DCP s in the Himalayan regions must be equipped with competable snow sensors and the number of DCP's should be increased in the Himalayan region.