Rainfall probability analysis for different agroclimatic zones of Bihar

Abstract

Proper management of rain water holds the key for successful planning in agriculture. Right from sowing to harvesting of crop, information on pattern of rainfall distribution and probabilities is essential for avoiding water stress and subsequently raising of good crop. The variability of rainfall both in space and time determines the water balance and irrigation requirements of crops. Various authors have studied the rainfall pattern and distribution for crop planning. Ghadekar and Thakare (1991) worked extensively on the rainfall distribution pattern over Nagpur region of Maharastra. Chattapadhay and Ganeson (1995) studied the variability of annual and seasonal rainfall pattern of coastal Tamil Nadu. Chaudhary and Tomar (1999) developed the stable rainfall period during crop season through an analysis of forty years data over twelve stations of Bastar district. In this paper, an attempt has been made to characterize the rainfall pattern, weekly rainfall probability and moisture availability in different agro-climatic locations of Bihar state. Daily rainfall data of Pusa (database1971-2001), Madhepura (database 1974-2003), Bikramganj (database 1931-2003), Patna (database 1981-2004) and Sabour (database 1972-2001) were collected and analysed. weekly, seasonal and annual rainfall distribution. The weekly rainfall probabilities were calculated using rainfall analysis software.