 Hello, I am Dr. Satish Kumar Kashi, Professor, Department of Civil Engineering, Valchan Institute of Technology, Sulapur. I am presenting a topic, Introduction to Indian Mansur rainfall. Learning outcomes of this session. At the end of this session, students will be able to describe atmospheric circulation patterns influencing Indian Mansur rainfall, elaborate about distribution of rainfall over India and quantify the water resources available over the country. So, this is a figure which shows variation of annual mean temperatures over the earth, over the globe. So, we find that the high temperatures are there at the equator and as we go away from equator we observe the lower temperatures. So, this temperature difference automatically creates the pressure difference of air and the difference in temperatures and hence the difference in pressures over the globe is the driving force behind the global wind pattern. So, we see here the global wind pattern which we have studied in geography. Now, this is a figure which tells us about the East Asia Mansur. So, in East Asia Mansur, shown by these black arrows we find the summer Mansur, shown by these grey arrows it is a winter Mansur. There is a teleconnection between the oceans and continents. Teleconnection means the simultaneous variation in weather and climate over widely separated regions, widely separated regions on the surface of earth. What I mean to say is that whatever sea surface temperature changes take place over the Pacific Ocean they have influence over an Indian summer Mansur rainfall. El Nino Southern Oscillation, North Atlantic Oscillation, Pacific Decadal Oscillation, Indian Ocean Dipole Mode such hydroclimatic teleconnections are observed over the earth. So, El Nino and La Nina are the important temperature fluctuations in surface waters of tropical eastern Pacific Ocean this region. The atmospheric signature of Southern Oscillation reflects the monthly or seasonal fluctuations in air pressure difference between Tahiti and Darwin, Australia. El Nino has regional impacts. So, how are the regional impacts especially for India our period of Mansur is June to September. So, in warm episodes of El Nino we will find that there is reduction in rainfall over India as well as also there are dry situations in this region in this region the wet situations are there. Whereas Indian Ocean Dipole Mode which influences the Indian summer Mansur rainfall. So, what is IOD? IOD is a pattern of internal variability with anonymously low sea surface temperatures of Sumatra and high sea surface temperatures in the western Indian Ocean. See here we observe low temperatures high pressures here in the red color region we observe the high temperatures and low pressures. So, again there are two modes one is negative dipole mode and positive dipole mode is exactly opposite to these two it means these two regions here we find low temperatures here we find another mode high temperatures here we find high temperatures low pressures here we find low temperatures high pressures. So, there is a fluctuation in this way this fluctuation also has effect on the Indian summer Mansur rainfall. This picture I am showing for understanding the geography these are the Himalayas these are the western guards these are the eastern guards and these are the north Indian planes. So, of course, the geography influences the rainfall pattern that one should understand. Now, this is another picture giving you the idea of geography of India. So, these are the western guards these are the eastern guards and these are the planes. Now, India and its river basins. So, this is a Ganga river basin this is these are the Vindhya mountains these are the Shatputa mountains this is a Deccan plateau here there are western guards. So, here we find the Tappi river here we find the Narmada river here we find the Krishna river here we find Godavari river here we find the Ganga basin. Indian summer Mansur brings rainfall in June, July, August, September and the winter Mansur brings rainfall to south India especially in say months of November, December and so. This particular figure tells you the normal onset dates of the south west Mansur. So, south west Mansur reaches here at the first June thereafter it reaches here along this line at the fifth June in Maharashtra it comes at Mumbai about say 10th June and ultimately it reaches by 8 July in Rajasthan. When Mansur is active this is one typical cloud cover over the Indian subcontinent. India has a network of rain gauges. So, this is the IMD network where we measure the rainfall continuously over a period of time India is divided into this is north-west region this is west central region this is peninsula region this is central north east region and the dark blue is the north east region. This graph shows us the monthly variation of all India rainfall. So, January, February, March, April, May we observe that about 80 percent rainfall takes place in June, July, August and September and then October, November, December again it recedes. The regions are further subdivided into subdivisions. So, these subdivisions are numbered for example, 7 andaman to Arunachal Pradesh say 14, Punjab 15 say Himachal Pradesh. So, these are the meteorological subdivisions of India. Now, for the homogeneous Mansur regions these are the characteristics number of subdivisions contained in the central north east region are 5 and 5,73,006 kilometers is the square kilometer area and similarly for these. Now, again region wise June rainfall is different, July rainfall is different, August rainfall is different, September rainfall is different and this is a total Mansur rainfall seasonal and annual rainfall statistics is also published for the country and the broad regions which gives us idea about winter rainfall, pre-Mansur rainfall, Mansur rainfall, post-Mansur rainfall and annual rainfall for different regions. This particular figure gives us idea about the all India summer Mansur rainfall 1871 to 2017. So, we observe. So, if average rainfall is there the point will fall on this line. So, the bars above this they show the rainfall above average and the bars below this horizontal line. So, rainfall below average in some year rainfall is above average in some year rainfall is below average. So, the bars shown by red give us idea about the drought situations drought shown by blue they give us idea about the flood situations. Droughts are associated with El Nino events as shown here for these particular years the floods are associated with La Nina events as shown by these points. Based on this data we have the average annual rainfall over India figure and we observe that rainfall varies right from say 0 to 20 centimeter over a year in say some portion of Rajasthan and going up to say 800 to 1000 centimeters in Meghalaya. So, in Maharashtra we find that in these regions we find 40 to 60 centimeter rainfall is there as we go towards east it is 60 to 80 in Konkan we find it is say in between 200 to 400. Based on the rainfall pattern one can know the drought zone regions of India. So, the Gujarat some post of Maharashtra, Karnataka, Tamil Nadu some portions of Rajasthan they are the frequently drought zone regions of India. From rainfall we receive average annual precipitation in volume units equal to 4000 billion cubic meter approximately average precipitation during Mansoon out of that is 3000 billion cubic meter means 75 percent. Natural runoff is 1986.5 billion cubic meter estimated utilizable surface water resource is 90 billion cubic meter it means this much we can use efficiently effectively remaining will always join the sea. Total utilizable groundwater resources are 433 billion cubic meter and total annual utilizable water resources including surface and groundwater are 1123 billion cubic meter. So, accordingly the per capita availability is 1720.29 cubic meter per person. So, just a reflection spot average annual rainfall of India is so and so answer is 890 estimated utilizable surface water resources of India are these are the options answer is 690 billion cubic meter. India is divided in so many meteorological subdivisions by Indian history of tropical meteorology answer is 13.9. Conclusions, El Nino Southern Oscillation and Indian Oshel Dipole Mode influence Indian summer Mansoon rainfall. India receives about 80 percent of annual rainfall in Mansoon months of June to September. Southern India receives substantial rainfall from retreating Mansoon in November and December. Rainfall distribution over India is highly uneven annual rainfall ranges from 20 centimeter to 350 centimeter. India receives about 4000 billion cubic meter of water from rainfall annually out of which 697 billion cubic meter of surface water and 345 billion cubic meter of groundwater can be used effectively. So, these are the references specials thanks to WIT Sulapur and IDP in educational technology IIT Bombay. Thank you.