Rainfall characteristics of north west alluvial plain zone of Bihar

Abstract

Rainfall data for the period 1960-2005 is used to analyze the probability of occurrence of deficit /normal / excess rainfall. The mean annual rainfall is 1200 mm with 28 percent variability; with standard deviation of 336 mm. July is the wettest month (average rains- 326.5 mm). Rainfall of August and September months shows lower coefficient variation- 57 percent. Each standard week from 25th to 40th receives a rainfall of more than 40 mm, indicating the crop suitable period from June third week to October 1st week.

Keywords

• Seasonal rainfall
• Gamma probability and weekly probability by Markov Chain