Abstract:
Kalahandi district of Orissa, India is known for drought and water scarcity problems. The agricultural system of the district is dominated by rainfed rice cultivation. The knowledge of the probable period of onset and withdrawal of monsoon and the intervening critical dry spells is important for timely seedbed preparation, selection of crop varieties and contingent planning for supplemental irrigation etc., to derive maximum advantage of monsoon rains for rainfed cropping. Drought frequency, duration, dates of onset and withdrawal of monsoon and intervening critical dry spells have been assessed using hydro-meteorological data. The analysis revealed that the northern parts of the district experience drought with an average frequency of once in every 4-5 years and in the southern parts the drought recur after every 5-7 years. The probability distribution of annual rainfall indicates that the probabilities of occurrence of 75% of its normal rainfall vary from 0.72 to 0.88, and the ranges vary from 800-900 to 2000-2100 mm. This witnesses that the distribution of rainfall is crucial for agricultural system in the district.
The water requirements for different kharif season crops have been estimated and the irrigation requirement for the critical dry spells have been worked out to plan for alternate supplemental irrigation. There is a vast scope for development and exploitation of surface and ground water in Kalahandi. A planned development and exploitation of groundwater may not only contribute as a sustainable source of water for supplemental irrigation but also for tackling the situation during drought.
