 Welcome back to rural water resource management week one lecture five. This is the last lecture for the first week. And normally what I would prefer is to go back through the weeks course lecture notes, and then reiterate how they combine together for every week. So that would actually put you in the right track to understand why we went through these different lectures, all the four lectures for this week, and then how it all gels together for the common interest which is rural water resource management. Let's do the recap of week one. What did we see. And this is a small example, the image I show here. What you see here is a lot of farm ponds or rural water resource management in Maharashtra region, right next to Mumbai on the outside. And you could see that a lot of land has been used to segregate water to store the water, and then use it for agricultural purposes because for drinking you don't need this many number of tanks. So, what did we see. First we introduced the course content, what is rural water resource management. We looked into concepts of differences between urban water resource management and rural, and we focused more discussions on the rural aspect. Then we looked into the hydrological cycle, where the water is available, how much water is available. I'll go again one more time today, because now after going through the hydrological cycle, the different compartments of water, you'd be in a better position to now relate back to the availability of water. That actually drives the, drives the force on why we need to learn and focus on water management for rural regions, right. Then we used a lot of units and quantification of water, we looked at different units, how they should be used to quantify water. And we also looked at footprints, we looked at water stress indicators, we saw how and why a particular region in the world is going to be water stressed, especially Indian regions. And within Indian regions, a lot of rural regions are going to be water stressed by 2030. We looked at what are the driving forces etc. So, at parts we looked at, then we looked at LPCD, which is the liters per capita per day. So how much water is used by a person per day in a household. And we also went through different values and different volumes of water that has been promised, ranging from 40 to 70 LPCD in the rural regions. And for urban regions, we saw that it is 200 LPCD. So, we had a discussion on why 40 to 60 LPCD has to be increased for better livelihood options, for better sanitation in rural regions, because initially there was no toilet facilities. But thanks to Swach Bharat Mission and other missions by the government, there is toilets, there is funds set up for toilets. But the water that is need to clean the toilets and for the drainages is still needs to be accounted for. And that is where the LPCD rates may have to be pushed up. So the government norms we discussed by 2030 by 2027, the government wants to push it to at least 70 LPCD. That will be enough water for people to avoid open defecation and then use the latrines through the Swach Bharat Mission. So once we defined the course content, we understood why we need to study rural water resource management. Then we looked at the units and different parameters to calculate the volumes of water needed and water used. Then we went into the hydrological cycle. So even till the last lecture, we looked at how the hydrological cycle is being spanned out. What are the key variables? What are the key drivers of hydrological cycle? We explained the fact that if the sun is not there, the hydrological cycle would stop and it will stop evaporation and transpiration. So there won't be complete loop. So all these factors we looked into the hydrological cycle. So today I would go from the atmosphere into precipitation, sublimation. So the other aspects because I want to close the hydrological cycle here. So some may be telling me that why I was not discussing how the other parameters are important. So I'll go through some of the parameters that I skipped in the rural part because now we're going to close the hydrological cycle. So we have volcanic stream. So let's start with the atmosphere. So we have clouds. I'm going to follow through this arrow and then we go back. So we have clouds in the atmosphere, which is nothing but water vapor, condensed water vapor. And then after condensation, it becomes precipitation. There are multiple types of precipitation. There is ice, snow and glacier deposits and there is rainfall. So there is thunders and rainfall you could see. So water comes down, condensers and comes down. Once it comes down, there is some rivers and surface flow. Surface flow we looked at, what constitute surface flow, lakes, streams, rivers, etc. But there is also snow and some of the snow can start to melt because of the sun. So the sun drives everything as I said. So because of the sun's radiation and the warmth, some of the snow which is deposited on the top of your high altitude mountains start to melt. And that water is called snow melt. So like your rainfall, which is your condensed water from clouds into precipitation and rain, you can have precipitation into snow and snow into water. And that water also comes back to the river. So you can clearly see here that the snow which is deposited on the top elevations are melted by the radiations and comes down as snowman runoff. So this runoff and your rainfall runoff combine together in rivers and open water bodies. Then some of the water, let's say surface water goes into the soil. I told you in the previous example that part of the water gets captured by the trees but then it goes down. And as soon as it hits the earth's surface, it converts to runoff which is your rivers, oceans, etc. But then also it has soil moisture. So it goes into the soil after planned uptake, etc. So we felt this part. Then let's come to this part. So some of the precipitation is also as permafrost and dew. Dew is a form of precipitation, very, very small droplets of water. And all of that can and fog drip, etc. All of that can convert to surface runoff. So we are drawing a line here. All the parameters have been discussed. The sublimation and the position is just conversion of water from one phase without going through an intermediate phase. For example, straight from snow, it can, without converting into water, it can be evaporated. So same thing, water vapor. Instead of coming back to liquid and then freezing to snow, you can also have sublimation and a position. So that is what this cycle is. It's a very, very small part but still let's get through all the important things. So we had this dew, sublimation, snow, permafrost, all of them convert to surface runoff. And the surface runoff goes into rivers and lakes and oceans, surface discharge, etc. So once the water both gets into the river body and a stagnant water body, there's a lot of evaporation, again, driven by your sun. So it's because of the sun's heat and radiation, you do have a lot of evaporation. So water evaporates from the top surface. So from freshwater lakes, from oceans, you see these arrows, big, big arrows showing that water is moving back into the atmosphere. So water started as a vapor condensed into clouds, then condensed into precipitation as liquid phase. And from the liquid phase, it goes back into vapor through the evaporation cycle. And then evaporation can cool down. Once the vapor cools down, it becomes clouds. So after the surface runoff and soil moisture, what happens? Some part of water gets as seepage. And once it seeps in, infiltrates into the earth. So this is where I said surface above and surface below. So below the surface, the water can infiltrate into the earth and come down as deep groundwater. So this is the deep groundwater, which is taking sometimes millennia, 1000 years to reach to a point. We will get through that when we discuss more on groundwater for rural regions. But mostly you see this cycle, which is the shallow aquifer. Water infiltrates, comes down into the ground and then seeps out. Some of the water can come out as seepage. What is it called in Indian terms? It is springs. So if you go to the Himalayan regions or mountainous regions, you see waterfalls, springs, which is suddenly in a hill or a mountain, you see water seeping out. So that is seepage. That is water which has gone into the ground and coming back out. So that seepage can be a spring, it can be a waterfall, anything that comes out of the ground. Then some of the water can also get directly into the water body. So we don't know how much this is because you cannot see it. So when you see a river or a lake, some of the water can also come from underground the lake. So that part is your groundwater. Same how water can come from the groundwater to the lake. Part of the lake water can also get down to the groundwater. So that is the groundwater recharge. And this is the groundwater discharge. All these arrows which are going from the groundwater into the earth is called above the earth is called your discharge. Whereas here it is recharge. It goes into groundwater. This doesn't happen that quickly and easily. So that is why we have wells. We have wells and farmers put in pumps in rural villages to pull the water out. So as I say, this particular phase, this particular drivers are very limited as much as you have this one. So recharge happens a lot. This doesn't happen that much. Why? Because the groundwater gravity force is there. So water by default wants to move down. Only when there is a pressure difference, there is some constrictions to flow. It moves out like this. Mostly by pressure difference. When the water always moves from high potential to low potential. So these are high potential energy going down to low potential energy. And same thing, high pressure to low pressure. So when it finds a weak spot in the earth, it breaks the part and then comes out. And that is where you have springs, water fall, etc. You see water gushing out. So when you see a waterfall, it's not water coming slowly. It's like gushing out with such a force. And that is because of the pressure difference. So as I said, a lot of recharge happens, but not much of groundwater discharge. And that is why people force it or we force it by using pumps, industry or rural pumps for litigation. Anything that pulls the water out against gravity and by spending a lot of energy. So then groundwater also gets stored here, which is the groundwater storage. So there is a tank, just imagine like a tank which is under the ground. It stays there because there is a void, there is a space. Water that takes long, long time to get in would not easily come out. So that is the groundwater storage. There's deep and then shallow groundwater storage. And if you hit it right by the pump and bore holes, then you can take it out. And that is what is happening in most villages. So you had all these precipitation converting into rivers and lakes and discharge. And then all of the water, if you see, goes back to the ocean. Be it groundwater, your river water, your lake water. So there's a very philosophical saying of this too. All streams, all water comes to one point. So that is this point, oceans. So it goes to the seas. Seas are smaller and the oceans are big. Pacific Ocean is big. Arabian Sea is small. So it goes to the seas. They are all of it and then goes back to the Indian Ocean for Indian context, I'm saying. So ocean is the place where it finally ends. All the water movement stops going into the earth side and then goes back up. And that going back up is driven by your sun. And as I said, you have your sun and the cycle is not complete until it brings it back to the cloud. So it need not be, you don't have to start from the cloud. You can even start from the ocean. The same cycle will happen. Water converts from ocean to clouds, clouds to rainfall, rainfall to groundwater, groundwater to freshwater, freshwater to oceans. So you could see here that the salinity is remaining back in the oceans. It is the same water, right? The oceans have water plus salinity. But when it evaporates and comes out and rainfall, it is called freshwater, which is, it is not saline. There's no salt in it. You can comparatively much, much, much lower, right? And this is what they force it in a desalination plant. They heat the water, pull it down and then do all those things or remove the salt out. So this is done naturally without any cost to the system by the sun. But if you disrupt the system, if you change any of these factors, then nature gets violent. That is what climate change is happening. So if you change all these, some of these parameters over evaporation, then big, big clouds come and sudden condensation comes, sudden convection comes. All these things happen when you disrupt these cycles in a particular fashion. That would be discussed more in a climate change kind of a lecture. But here for rural water management, please understand that it is not the different waters that are going back to the atmosphere and oceans. It is the same water, whatever water you don't hold, it gets back to the oceans. And from there, it goes back into the cycle. There are some waters which get stored in the groundwater, lakes, rivers, dams, etc. Those are different. But again, it eventually evaporates or transpires. So that part I missed. So let's look at it here, which is your plant and animal update. Even humans, we transpire. When we job, when we run, we have sweat. And then the sweat evaporates. So there's a lot of transpiration. When we say sweat, it is transpiration and transpiring. That's what we say, right? So you have your plants, your plants take up the water and transpire. So all this transpiration would go back into your atmosphere. And if it is just the water bodies, it's called evaporation. If it is with the plant, it is called evapopranspiration. So that's a big, big factor. Look at the arrow size. It is big. All the other arrows are smaller compared to your upgrade of evaporation. And the evaporation from water bodies is also big. The evaporation from smaller bodies is small because the volume of water is small, but oceans is really, really big. So that is why these big, big arrows are coming. We also discussed the localized need for hydrology in rural areas, which is understanding not all these parameters are important, but very specific parameters for your research area. And most of the time, you will not have the hydrology of snow, snow melt, et cetera, to discuss even the oceans. You will not have it, right? You won't have a dam. You'll have a channel, but not a dam. So for rural water management, you'd be mostly looking into this part, which is your weeds, crop trees, how much water they take, how much water they transpire, evaporate, et cetera. And the idea is this one. How do you lessen? How do you lessen or reduce the conversion of rainfall into runoff so that if you cut this proportion of water, you can save this water back into the cycle, okay? So understand that if you cut one of these, the other components can take the water up and use it for their respective purposes. It gets divided for other purposes. I would like also to stress the fact that for water management is really, really necessary, especially in nowadays where you have climate change extremes of floods, droughts, et cetera. So the composition might change drastically and availability of fresh water is decreasing day by day, okay? And for case of rural India, we looked at off the total water, only 2.5% is fresh water and off the freshwater only 21%, groundwater 20% plus easily accessible water is 1% is available. And even that, of all that, only a part of the groundwater you could use. And what happens when there is no rainfall? People go, farmers go to groundwater to recharge or irrigate their fields. Or they look at dams and channels. Not everywhere we have irrigation command areas, but we do have wells almost everywhere in India where you go and take the water feditation. Even houses have groundwater, correct? So understand that we would be driving more focus on water management, how you conserve rainfall, water, and then use it for agriculture. But also we'll be looking at this freshwater percentage. The access is getting very difficult. So that is why a lot of people are putting more money on the engineering aspect of pumping. A lot of water is being pumped. But again, that is not sustainable. As I showed in my hydrological cycle, some of the groundwater takes thousands of years, if not 100 years. So most of the time you would see water recharging even across the boundaries of India, that we are pulling now. So that is how much water you may be using. We don't know where the recharge is happening for some reasons. It might be within the boundary of India, it may go out of the boundary of India. So it is very, very important to understand where the recharge is happening. And for that we need data which is really not available. So it is better to conserve the groundwater. Use it wisely. Just because you have water, don't just use it everything in one go. And for that, a clear understanding of the hydrological cycle is needed. Where you use water is needed. Let's take a look at the freshwater stress as per UN body. In 1995, we saw water withdrawal as percentage of total water available. For example, if I have 100 liters, what is the percentage, how much water am I taking out? So you could see that in the world, India was always taking more than 40% or around 40 to 20% of the total water. So you still saved around 60% of the water in 1995. But then the case is slowly changing. The projections are really bad. And it's saying that you're going to use more than 50 to 60% of your water. So that is what the projections are given for 2025. And even the countries which are in the green, which means which are using less than 10% of the water they use, they are converting into orange and yellow. The sad part here is you don't see anyone greening, which means you don't see from 1995 some countries which were in the yellows and greens or yellows and orange converting to green color, which is a safe color. You don't see that. So what is happening is all the countries are increasing their water use. They're increasing the water withdrawal. And by that, they might be breaching how much water they can use. It may not affect those countries in green because they just slightly increased. Like for example, Canada or South America, you don't see how much water use Australia, et cetera. But if you come to the Middle Eastern countries, India, China, you see a lot of water being used. And there is evidence of further increase of water use. Where is the water use now? The first image shows you that the water has been used a lot. Let's see the evolution of global water use, withdrawal and consumption by sector. They're given only four sectors, which is agriculture, domestic, which is drinking water and your water for evolution, bathing, et cetera. Industrial water for industries and reservoirs. Reservoirs is just a storage. You see that there's not much change you expect from 2000 to 2025 in reservoirs, which means that new reservoirs are not coming out. If you go and look at the news articles, you don't see any big dams being proposed. Maybe small dams a little bit, the height has been increased, but the proposals are not as much as it was 10 years ago or 20 years ago. Because people are slowly understanding that a centralized approach for water storage may not be the solution. Reservoirs are coming down, and the forecast is also saying that it's going to be stagnant. You're not going to increase it. But strikingly, you do see that the withdrawal, the withdrawal rate is going up, which is a dark green for agriculture, exponentially high, but also the consumption is going up. And the wastage, the wastage is the difference between how much water you take and how much you consume. So the wastage is getting bigger and bigger. That is the concern. Initial days in 1900s, we did not waste that much because the withdrawal was less. The consumption was almost there. We knew how much water we would do. But now because of everyone having access to pumps, everyone having access to decentralized water supply, which is your groundwater, you are seeing a lot of wastage. Where water can be conserved, people may be using it for fallow irrigation, flood irrigation, rather than drip irrigation or other aspects. And that is what this graph was showing. The forecast is not looking good. The agricultural consumption is going high. The withdrawal is going high. And the consumption is also going high. But the problem is between the withdrawal and the consumption, the wastage is going high. You also see that the withdrawal for domestic use is going high. And the consumption is almost the same, 40 liters per day, 50 liters per day. So there's a lot of wastage. So a lot of wastage is happening. Industries, they do consume a lot, but they have the money and the technology still conserve water. So some of them may be putting in some systems to conserve water. So these volumes are all on the same scale. So you could clearly see that compared to the water availability and use, agriculture ranks the top followed by domestic industry and reservoirs across the globe. So this is a study by the UN and it clearly says that agriculture is where we first need to rescue or conserve the water resources and then flow lead to domestic industry and reservoirs. So this is why this course is very important. Agriculture happens in rural India and it is very important to go back to the roots and find where the water use is high and is it possible to conserve the water because the farmers are still the same stage, which is economic stage. It's not like they use a lot of water and they convert it to money. So where is the gap? Why are they not becoming rich? Why is the water being used at such an intensity? So that is what is very important for the future generations. So this course would put you in track to understand where the withdrawals are high and how to conserve water. Therefore there's a need to focus on rural water management and again I would like to propose that is the course, that is the title of the course that you have signed up. So it is a very important study area and to wrap up. I will not get into the units again, but please have a book of units. Understand that because we were ruled by the British earlier stage, we still have a lot of English units, but because of the science, evolution and development, we do have metric units more. So metric units are SI units are centimeters, square kilometers, volume and liters, etc cubic meters, but then you also switch back and forth in the English unit of inches, feet, still cricket we use yards, right? And you could also see velocities in cubic feet per second in discharge curves, etc, etc. Some properties are still okay. Globally we are using the same terms like kilograms, grams, metric tons, all those things are okay, but somewhere we also switch back and forth to inches. So acres, for example, for agricultural area. So it is always important to understand the conversion rule. So easily you can have it on your mobile phones or you can have it, don't by heart it, but have it ready for reading through doing my exercises, etc. So this I would like to conclude the first week of lectures. I hope you all enjoyed the introduction to the course and why this course is very important. It is not a traditional course. It is going to be a sensitization course where you understand the need for rural water development and hopefully understand where you could put the efforts in conserving water for India.