 Welcome to AG course or GIS application and now we will be seeing about we have seen what are the land degradation, water availability, water demand, what is the difference. What I mean the extreme events which is expected during this climate change is the drought. So, now it is before we go into the what are the different and how to do that there is a need for what is drought. What is the drought, how the drought could be characterized because drought is of importance to all the people those who are working on the surface of the air. Now what we try to do is we will try to characterize what all the different features and how it is classified and how we can able to understand the parameters and then make our agriculture profitable or it is productive. Before going to drought we have to understand what is the water stress and the different terms which are being used in the water related issues. One thing is a water stress and another thing is about what is the water scarcity, what is the drought and what is the fine. These are all the different different wording different terms which are used to define what is the water stress is or what is the water non-availability conditions for a plant and the other activities. Now when you look at it what is the water stress and when the demand exceeds the need then we call it as a water stress. So which causes some trouble for the fresh water resources either in the form of a quantity and or in the form of a quality issues that makes the difference. This water stress which induces plant degeneration of the leaves and other activities that causes that growth pattern there is some amount of deficiency which is being done on that. That is what is water stress. We have stress means we are overloaded and we do not get the normal activity to complete it possibly. Whereas when it comes down to the what is a water scarcity it is the availability of the water to meet the requirements of the region that is what we call it as a scarcity. Suppose if you want about 100 liters and if you get about 50 liters so your requirement meant is not fulfilled. So what do we do with the unfilled water where do you get the water how do you complete your activities that is what the water scarcity which is there. Whereas when it comes down to the drought when you say drought it is it starts with the below average precipitation in of a given region that leads to water supply to the plants drinking water and other activities whether including surface water as well as ground water which is not able to support the production of the crops that is what the drought. It is a temporary period may be for a 15 days may be for a month and if there is going to be a rain again that things will come back to the normal. So that is what the it is not a permanent feature it is the temporary feature may be for a shorter period or may be for a longer period. Now what is the another term which is associated term is famine. Famine is nothing but it is a prolonged conditions of drought conditions which leads to scarcity of food caused by crop failures and as well as there is a population imbalance that means population moves from one place to another place there is a government policies that has led to epidemics starvation as well as increase to mortality. So here the term is a total integrated impact on the region because of the water or because of the total drought condition leading to mortality and all. So if you understand what are the different definitions of a different different terms which we are doing it will be easier for us to remember and then do that. Now what happens due to the drought it is a common feature there is all the crops are not growing and it is all deceased and it is weeded out people just move out for water from so many so much of distance and here it is the plants whereas this big trees which are there they also get into some sort of a trouble the leaves becomes gray yellowish and it goes to brownish color that means there is not much of water at the root zone to support the growth. Now what is the situation when it will develop it is deficit of precipitation that means less rainfall and so that the desired amount of water is not available the storage system like reservoirs lakes and do not have a sufficient water for supply then crops gets lesser water to meet the food requirements and there is a sale in distress condition sale in distress condition means when there is no productivity no livelihood then what happen is the existing things resources are sold at a distress condition so that he has to survive. Now what is the difference now is why we need to understand better is the drought instead of making a pro approach so we make it as a crisis approach as and when it comes we just move here and there and spend our resources instead of phase doubt a process is not being done. So now resources also there it is you are likely to use it here and there without the proper accounting activities whereas it is risk based capacity management practices need to be done whereas when it comes down to see the climate scenario and climate scenario what it says is that there is frequent drought conditions are possible and in this case what we have done is we have already depleted because of the drought without unprepared drought conditions. This left out is alternative sources we have tapped out really so now what is happening is there are resources managed vulnerability analysis is needed depending upon exposure to that sensitive to that and also adaptive capability that is what is needed now in the drought management. Now drought everybody looks at the drought everybody says that they are on the drought and they have the importance because it is the less rainfall so meteorologists they talk about drought that is what we call it as a meteorological doubt the happenings why it is happening is it is because of the deficit in rainfall there is a high temperature and evaporation that means water losses are very heavy what do we do in this type of thing is water mapping the water cloud cloud bearing clouds that is what we did it in the weather clouds then measurements of snow and rainfall which contributes in quantifying the information and we have to look at the local YARMA circulation and whether it is able to dissipate the water bearing clouds in this area. So this is what people call it as meteorological drought when it is going to be a from the when it is different from the mean average temperature we call it as a meteorological drought that is what we try to do that. Another thing is about the hydrological drought what hydrologies they try to do say is it is they based on the river flow based indexes river flow based assessments are possible or that is what is being done then they look at it the contribution in a river basin is based on the runoff springs and uniform rainfall pattern we which we need to do that to understand the river flow from the mean if it is going to be less than the mean of the average for 10 years or whatever it is that is what people call about river flow related. The river reservoir storages see reservoir when we try to store water then there are storage levels may come down if the storage levels if they come out then they I may not be able to store enough water to meet the demands. So then we had we need to do understand what are the legal and illegal lifting of water diversion and flow rates are needed when it then another part of the water is ground water level. So ground water is our supplementary thing when whenever we have some shortages we try to depend on the ground water there are certain places where ground water is the only source of water where they use it out if they do not get the water then they will be in trouble. Then ground water level it is for a level meaning then as well as non portable water drinking water it needs a quality type of thing. If there is any fluctuation if there is any deviation in the existing pattern then that is comes under the hydrological rule. Then as a agriculture what we want to know is we want sufficient amount of water to form to grow the crops as well as get the food security done. But when I this agriculture what they need is it is not only one time water at every subsequent weeks there is a need for irrigation there is need for water if it is not available either to the demands demand requirement then we try to say the growth critical growth of the plants or the crops they will come down and that plant growth deficiency will be shown in the form of a crop yield. So grain production as well as the fodder so when there is how do we do that is agriculture crop area type of crop reduction in the area of the crop and if the crop conditions if it is differs from the normal growth pattern then we call it as a agriculture drought is happening. There is one more term which people they use about is the economic drought this is here it is a fluctuation in commerce. Commerce is nothing but a business there will be more distress sale distress sale in the sense I need money I have to sell whatever I have got. So that is happens because of the short supply of food items or unstable commodities. So these are all the criteria which is used in estimating the economic drought. Now when you look at all the four different type of drought even everything is possible in this world so what is happening is they do not occur simultaneously the first one to happen is reduced in the rainfall pattern followed by the agriculture activity followed by the utility aspect that is the agriculture aspect followed by the economic aspect. This is a entire cycle is possible and then cycle can be improved upon provided if there is going to be a good amount of rainfall then everything gets eased out and you are coming back to the normal system. So this is a cyclic process one after the another it does it first when it happens you say it is a drought then second thing is whereas these people they have got enough water to take care of the thing that means next year even if it is a good rain this portion the hydrological portion where they have enough water to cultivate and then come up. Whereas this is the agriculture it is a phase wise activity from the phase of sowing from the phase of maturity then harvesting season. So it is based on the phases of the crop growth activities whereas the economic is always the backbone about that. So this is what the different perspective of drought wherever whichever person when the person who is going to affected is the person on the ground and he may be affected because of all these factors. Now when you try to do what are the different significant drought vulnerability in the agricultural systems is one thing is biophysical factors like climate and soil whereas the technological activity that is because of the irrigation depends upon water availability in a local scale or in a watershed scale or in the river basin scale and whereas the socio economic activity is nothing but depends on the land use land use is nothing but a crop area activity. So when you want to do a mapping is vulnerability mapping the vulnerability mapping should be based on the agro-climatological factors then what are soil holding capacity of the things and as well as the agriculture system what are the different type of agriculture system based on rain food range land and other things. This based on this mapping what we try to do is areas which are vulnerable to drought on so many factors. So it leads to the how do you manage these vulnerable areas is the agriculture risk that is based on the land water management is one thing tillages another thing storing that is water harvesting then supplementary irrigation is having enough water for untoward instances then where is the increase in the water use efficiency this is how you will be able to manage the agriculture risk develop due because of the drought activities this is what is needed in this area. Now this slide shows about river flow river flow could be when it is less when compared to the normal mean then we call it as a drought whereas the stream flows there are we may have to understand there are two things one is the perennial stream where you get water every throughout the year whereas intermittent things somewhere it goes somewhere it is not going whereas the FEPRAM channels they flow water only during the immediately after the rainfall. So when what we have seen in this lecture is what is a drought? Drought is nothing but a non availability of water because of the rainfall or storage or anything for our growth purpose either in the agriculture in the crop growth period. So which leads to some amount of deteriorating condition of the plant growth that leads to the crop which we are talking about as a drought situation. This drought situation is a temporary period it is not for a longer period and it may if it gets improved up provided if there is going to be a rainfall. So that is what we have seen it we will try to see and what is the different drought vulnerability and the risk management in the next lecture. Thank you.