Rainfall trend analysis in Northernwest Bengal from 1901-2015

Abstract

India is home to an extraordinary variety of climatic regions, ranging from tropical in the south to temperate and alpine in the Himalayan north, where elevated regions receive sustained winter snowfall. The nation's climate is strongly influenced by the Himalayas and the Thar Desert. The Thar Desert plays a role in attracting moisture-laden southwest summer monsoon winds that, between June and October, provide the majority of India's rainfall. Being a very big geographical area India experience much variation in the rainfall pattern as northern India get rainfall during the monsoon season while south India get rainfall on the time of Retreating monsoon. In the same we can observe difference in rainfall in the northern part of west Bengal and southern part of west Bengal because northern part of west Bengal is near to The Himalayas while south Bengal is near to Bay of Bengal. But in the current study we are working on northern eight districts of West Bengal.Thethesis brings the result of the analysis based on the recent 115 years of data (1901-2015) on the mean spatial rainfall pattern. The study aims to investigate rainfall trends in Northern part of West Bengal comprising of eight districts. The study is carried out to understanding the underlying feature for the purpose of forecasting and in identifying the changes and impact that are very crucial for an Agro-based economy like the one of West Bengal, India. Here we studied using monthly data series of last 115 years (1901-2015).The present study, based on the data for the period 1901-2015, examines the seasonal and annual mean precipitation by the method of Mann-Kendall analysis, Sen-slope estimator and Innovative trend analysis (ITA).