Analyses done by the India Meteorological Department and the Pune-based Indian Institute of Tropical Meteorology show the same trends as depicted by the recent report of the Inter-Governmental Panel on Climate Change (IPCC) relating to temperature, heat waves, melting of Himalayan glaciers, droughts and floods at places and the rise in the sea level.
However, at the national level there is no trend in monsoon rainfall during the last 100 years.
The country, being divided into different eco-climatic zone, there are some distinct regional rainfall patterns recorded over the years. The weathermen see that these distinct patterns being disturbed with the increase in rainfall along the west coast, north Andhra Pradesh and north-west India.
Decrease in monsoon rainfall is marked in the east Madhya Pradesh and adjoining areas, north-east India and in parts of Gujarat and Kerala.
According to the meteorologists, a significant warming trend has been observed along the west coast, central India, interior Peninsula and in the north-east India.
However, cooling trend has been observed in the north-west and some parts of the southern India.
Instrumental records over the 130 years do not show any significant long-term trend in the frequencies of large-scale droughts or floods in the summer monsoon season.
The total frequency of cyclonic storms that form over the Bay of Bengal has remained almost constant in the period 1887-1997.
In the current season, the monsoon system has entered a period of temporary crisis after July 11. The rainfall over the country in the week ended July 18 was less by 25%, with 13 out of 36 meteorological subdivisions experiencing deficient rainfall and 9 with scanty rainfall.
The regions of low rainfall in the last week are northern, western and central parts of the country and also a part of the Peninsular India. In the following week ended July 25, rainfall over the country was less by 30% with 15 meteorological subdivisions received scanty rainfall, while 10 received deficient rainfall.
The patch of low rainfall is contiguous with large areas of northern, western, central and southern India.
Only areas to receive good rainfall in the week was Bihar, Jharkhand, West Bengal and north-eastern India, Uttarakhand, Rayalaseema in Andhra Pradesh, Tamil Nadu and the Lakshadweep. Due to the erratic pattern of the monsoon, particularly in June, this year, the sowing operations in several parts of the country was delayed.
The floods and heavy rainfall in early July also took a toll on the standing crop.
With a view to mitigate such a situation in the near future, the agriculture ministry has planned to select varieties which are resistant to droughts, floods, salinity and encourage their cultivation in specific regions.