IMPACT OF VARIABILITY:-Variability is the major cause of floods and draughts in an area. Variation in rainfall may occur because of global (like El-Nino, IOD) or regional (like positioning of Jet Streams) or local (like areas where two monsoon branches meet) factors.

 Variability < 25% – Western coasts, Western Ghats, Eastern plains of Ganga through North East, Northeast part of peninsula (Avg. Annual rainfall > 100 cm).

 Variability > 50% – Western Rajasthan, Northern part of J&K, interior parts of the Deccan Plateau (Avg. annual rainfall < 50 cm).

 Rest of India has a variability of 25-50% and these areas receive an annual rainfall of 50-100 cm.

 In the northern India rains are likely to fail if the rain bearing storms are not very frequent along the monsoon trough.

 ITCZ gets stuck on Himalayan foothills due to its interaction with the Sub-tropical jet. This causes breaks for several days over north India, while causing incessant rains in hills.

 Over the West Coast, the dry spells are associated with days when winds blow parallel to the coast.

Cropping pattern refers to the proportions of area under different crops at a particular period of time. Variability of rainfall plays a crucial role in determining the cropping pattern in India as variability of rainfall and amount of rainfall are inversely linked.

 Areas of high variability are flood or drought prone. Hence these are not agriculturally well developed regions. Availability of irrigation in some areas can compensate in times of scarcity but problem of floods is still not addressed.

 Cropping pattern in areas with less variability- Rice is the most important crops of these areas.Tuber crops, plantation crops are also grown. Vast areas are marked by monoculture of rice.

 Cropping pattern in areas of medium variability-.Different crops requires different amount of water and mixed cultivation is often practiced. Rice is grown if sufficient rainfall is received in September, otherwise millets are natural priority. Wheat is the principle Rabi crop

 Cropping pattern in areas of high variability– The major crops in these belts are millets, jowar, bajra and ragi. Mixed cropping is very common in which pulses are mixed with cereals. Groundnut is an important commercial crop grown in dry areas.