 Welcome to the course introduction for groundwater hydrology and management. This is Professor Penan Chinnasami from the Indian Institute of Technology, Bombay. I am a faculty with the Center for Technology Alternatives for Rural Areas, SITARA, which is a very unique department for rural technology and development. Water is a very important part for rural development. Of the water resources in the world, almost 2.5% is the only available freshwater. Remaining are mostly saline and not usable. Of the 2.5%, only 21% is easily accessible. So of the freshwater, only 21% is easily accessible and of that 1% is in the lakes and rivers whereas 20% is in groundwater. On this note, groundwater is such an important freshwater resource. Most importantly, with climate change, groundwater acts as a buffer because during a flood or drought there is a lot of scarcity for water, plants do not get enough water for which people use groundwater. So groundwater has silently become a mitigation and adaptation tool for climate change. With so much benefits and also ease to access, groundwater has been used widely. We should also note that groundwater has played a key role in increasing the agricultural productivity for India. Groundwater opened up a decentralized water system because every house would put a well and take groundwater for their needs. With such prolific use of groundwater and ease in access for pumping, the groundwater use has almost become unsustainable because groundwater takes a lot of time to recharge whereas with technology we could easily access it. So it is very important to conserve groundwater. Before we need to conserve groundwater, we also need to understand the physics behind it, how groundwater occurs and how to manage it. So this course would give you an introduction to groundwater hydrology. We will discuss the physics about groundwater and understand the key drivers for groundwater recharge and discharge. We would also go into the equations, specific equations to understand groundwater movement. We would discuss about the shallow and the deep aquifers followed by some modeling concepts. We will also look into some case studies on groundwater use and how you can use it sustainably by different methods. So we would look into a focused groundwater hydrology scheme to understand the key drivers for recharge and discharge. At the end we would stop by giving some recommendations. So this course is tailored made for understanding the groundwater and then sensitizing people on why groundwater occurs, how it occurs and how it is being used and what are the methods for sustainable groundwater management. The course takes a lot of understanding and lessons from course textbooks which are given in the website. We would also be using government reports and records, some data we would be pulling out from the government websites to look at how we can understand the data. We would also look into some remote sensing analysis, how satellites are used for groundwater and we will discuss some case studies. The lecture also would use some of my field experience as a groundwater hydrologist, some of the data I have collected over the past 15 years and we would discuss that in class. This course is very important for water resource managers who want to understand the water and conserve water and more importantly groundwater. This course is suited for earth and environmental science students, civil engineers and water policy makers. I would like to welcome all of you to this groundwater course. Thank you.