Assessment and Management of Groundwater Resources

Abstract

Assessment and management of groundwater resources is important for their optimum utilization and to avoid any adverse effects. First of all, it is necessary to have a prior knowledge of the distribution as well as hydraulic and geochemical characteristics of aquifers as discussed in earlier chapters. It is also necessary to know the amount of natural recharge and groundwater abstraction. Management of groundwater resources is simple when natural recharge is more than the abstraction. However, when the aquifer approaches full development, the management problems increase significantly. For example, in the past half a century, there has been an explosion in groundwater development for irrigation, domestic and industrial uses, particularly in India and China. Abstraction of water more than natural recharge leads to decline in groundwater levels, which causes uneconomic pumping lifts, land subsidence, deterioration of water quality, sea water encroachment in coastal aquifers and so on. In areas where an aquifer is hydraulically connected with the river, lowering of water table will reduce the groundwater discharge into the stream and may result in induced recharge from the river into the aquifer. On the other hand, extensive use of surface water for irrigation may cause water logging and salinization of water and soil. These problems may arise both in granular rock formations and fractured rocks. Groundwater modelling is a useful tool to study various problems related to effect of various stresses on groundwater regime (Chap. 19). The various technical aspects of groundwater assessment and management are outlined in this chapter. Most of the examples cited are from granular formations as such studies in fractured rocks are limited but the general approach is the same.