Abstract:
The agricultural productivity depends upon chiefly the occurrence and distribution of rainfall in a particular region. But due to non-uniform distribution of rainfall and prolonged dry spells during monsoon season and crop period, the dry land agriculture in arid and semi arid regions is becoming difficult. The identification of dry spells and wet spells to find out drought occurring conditions are complex because of the fact that, it requires analyzing the vast hydrological data in a systematic order. Anantapur is one of the drought-affected districts in Andhra Pradesh. Due to prolonged dry spells and ill distributed rainfall the district under went a metamorphosis from drought to desert prone area. Keeping this in view, the present study is carried out to identify the droughts in Anantapur district by analyzing the daily rainfall and evaporation data for a period of 21 years from 1979-2000 by the application of DBMS approach by developing programs using Microsoft Visual FoxPro Software. From the data analysis, dry days, dry spells, wet days, wet spells, monthly, seasonal and annual rainfall, driest and wettest months were obtained. The interpretation of the results yields that it is possible to identify the likely hood of occurrence of dry spells and wet spells. The onset of monsoons was late and consequently the late sowing of crops which results in crop failure. The identification of dry spells is therefore helpful in agricultural planning, reservoir operations, releasing of water to canals for irrigation and for planning Cloud seeding operations.
