ICS 17.120.20                         WRD 10

Reaffirmed 2022

NATIONAL FOREWORD

This Indian Standard (First Revision) which is identical with ISO 6421 : 2012 ‘Hydrometry - Methods or assessment of reservoir sedimentation’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Reservoirs and Lakes Sectional Committee and approval of the Water Resources Division Council.

This standard was first published as IS 13665 : 1993 ‘Sedimentation in reservoirs - Method of measurement’. The committee has now decided to revise this standard under dual numbering system.

The first revision of this standard has been undertaken to align it with the latest version of ISO 6421 : 2012 to align with the latest international practices.

The text of ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words »InternationalStandard¼appear referring to this standard, they should beread as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practice is to use a point (.) as the decimal marker.