12. Sustainable Path of Extraction of Groundwater in Tank and Canal Command Areas

The objective of optimal control is to arrive at a temporally optimal allocation of groundwater over time horizon that will maximize the net present value of benefits from extracting the resource over the entire period. A typical problem is that of choosing optimal levels of decision variables over time. The volume of groundwater extracted is the control variable. The state of the system given by the stock of groundwater at any point of time is called the state variable. Changes over time in the state variable(s) are represented by the equations of motion, which are assumed to be the functions of the state variable, control variable and random variable(s) at the moment of change. In this chapter, the optimal path of groundwater extraction is demonstrated considering groundwater use for irrigation under tank command and canal command; for comparison, groundwater extraction with no such recharge facility is considered. While the optimal control technique offers solutions regarding sustainable path of extraction of groundwater thereby enhancing the age and life of irrigation wells, unless the society of farmers adopt the optimal path, no individual farmer will be benefited. Hence the dire need for creating awareness for farmers regarding sustainable path of extraction of groundwater for irrigation.