How does the groundwater form? How does it move, flow and store? A six module course designed to detail these and more questions on groundwater
The Advanced Centre for Water Resources Development and Management (ACWADAM) has created a power-point course to explain the formation of groundwater and its management.
The course consists of 6 modules; it includes the basics of understanding groundwater, study of geology, groundwater level and movement, planning and management of groundwater, storage and flow of groundwater and water quality. The modules have been made into succinct power-point presentations that include charts, diagrams and photographs besides the written word.
In the first chapter on 'The process of understanding groundwater', talks about the basics of groundwater and its functions. The module provides a rationale as to why it is important to understand what groundwater is.
The second part of the module 'Geology' deals with the study of rocks. The authors at the very onset provide a table of different types of rocks. They make things easier for students by providing photographs as examples. The relationship of rock type, shape of surface to groundwater is explained in this chapter. The authors also point out to the link between openings in various rock types and groundwater.
'Groundwater level and movement' deals with four basic concepts - infiltration which is the entry of rainwater into the ground, recharge which is the addition of infiltrated water into the groundwater - its types and sources, discharge of groundwater and movement of groundwater.
The chapter while explaining that there are two types of recharge - natural and artificial also gives a clue about rainwater harvesting. It is also pointed out that groundwater also has catchment and command areas like a watershed. The chapter also discusses how groundwater flows and concepts like 'elevation' and 'pressure' are also introduced here. The chapter also discusses the determining of groundwater recharge and discharge through water-level fluctuation and water level contours.
The fourth module 'Storage and flow of groundwater' begins with the entomology of the word 'aquifer' and its definition. The different types of aquifers is explained through diagrams. The authors use diagrams to explain the functions of aquifers which include storage and flow of water. Formulas are provided to determine volume of aquifer storage. The authors also introduce the Darcy's Apparatus and Law here to determine rate of flow. Formulas to determine hydraulic gradient, quantity of water flow are also explained.
In the fifth module, 'Planning and management of groundwater', the authors begin with providing a context to groundwater in the natural environment and state that it is part of the hydrological cycle. The authors also point out to India's use of groundwater sources. The chapter essentially deals with how groundwater can be used sustainably. They explain that the key ingredients for proper groundwater management include the integration of groundwater development and watershed management and these include understanding the resource which is groundwater, use of proper technology and social engineering which includes community participation and training.
The final chapter is on 'Water quality'. The chapter begins with explaining the chemistry of groundwater and its characteristics. The authors explain how water properties like pH, hardness, TDS can change. Key rule of thumbs like the relation between dissolved salts in water and its depth and time are explained. The chapter also discusses the sources of pollution of groundwater. The protocols for sampling and analysis of groundwater finds important place in this chapter. The use of Wilcox diagram and Piper diagram for the analysis of data generated from such sampling is also explained here.
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