Drought -- National Drought Mitigation Center

 

Title

Long-Range Forecasts of Southwest Monsoon Rainfall Explored for India

Document Type

Article

Date of this Version

October 1995

Comments

Published in Drought Network News October 1995. Published by the International Drought Information Center and the National Drought Mitigation Center, School of Natural Resources, University of Nebraska – Lincoln.

Southwest monsoon rainfall (received during June–September) determines the fate of millions of dryland farmers as well as the status of national food security in India almost every year. The need for information about southwest monsoon rainfall is great in these areas. An accurate long-range forecast can help farmers increase agricultural productivity in good rainfall years and negate the sudden downturns in agricultural production during anticipated drought years by giving farmers sufficient time to adopt drought-resistant crop varieties and appropriate crop, soil, and water management practices. The India Meteorological Department is now able to make all-India long-range forecasts of southwest monsoon rainfall accurately using a power regression model based on 16 regional and global parameters from 1988 on. However, these forecasts have seldom been used for strategic planning and management of agricultural production in any of the regions of the country, because the degree to which the all-India forecast is likely to hold true at microlevel is not known. The reliability of the forecast needs to be established at microlevel in order to make effective use of the long-range predictions for agricultural planning and management in rainfed areas. Therefore, an attempt has been made to examine the validity of the long-range forecast issued for the country as a whole for agricultural planning and management at the Jhansi and West Uttar Pradesh Plains meteorological subdivisions.

The present investigation is based on seasonal (June to September) rainfall data for the years 1958–92 at the West Uttar Pradesh Plains meteorological subdivision (subdivision no. 11). The seasonal rainfall data for the same period for Jhansi have also been considered to examine the extent to which the long-range forecast was relevant at microlevel.