A study on the Floods in West Bengal and West Uttar Pradesh during September-October 1956

Abstract

In connection with the study of extensive floods during September and October 1956 in West Bengal and parts of Uttar Pradesh, old records of rainfall dating from 1891 were examined. Several periods of heavy rainfall during the period, end of September to beginning of October, were found. Detailed examination of the district rainfall, with the help of standard deviation and coefficient of variation of daily rainfall during the chosen period revealed considerable variability within the district. One case (1922) has been studied further by considering the isohyets during the period of heavy rainfall. In the case of Jamuna Floods a few self-recording rain gauges in the mountainous catchment were used to prepare the intensity-pattern. These on comparison with the hydrograph at Tajewala show striking characteristics. Delhi self, recording raingauge records and Jamuna Bridge river gauge records; have also been examined. It is concluded from the above studies that the heavy rainfalls towards the end of September and early October 1966 were not absolutely unique. Cases of early occurrence of heavy rainfall during the same period are available, thus showing that heavy rainfall have occurred in the past during the period, end of September and early October when there were on atomic or thermo-nuclear explosions polluting the atmosphere, contrary to a popular view which seems to have gained ground that the heavy rainfalls are unique and direct result of atomic explosions.