Essay About Groundwater Resource

2.1 GROUNDWATER RESUORCE

Groundwater plays an important role in national development; hence, its management is of great importance. The demand for groundwater is increasing with time due to a number of factors such as high population growth rate, availability of groundwater, deteriorating quality of surface water, etc. (Table 2.1). According to NGWA (2016), the estimated rate of groundwater extraction around the world is 982 km3/year. About 60% of groundwater extracted globally is used for agriculture and the remaining 40% is used for domestic and industrial purposes. However, in some nations especially developing countries, more than 50% the exploited groundwater is for domestic use even though globally groundwater offers 25% to 40% of the

Table 2.3 shows the percentage of groundwater used in agriculture in some countries. The last 2-3 decades have observed an increase in groundwater use for irrigation in many parts of the world (Llamas, 2005). The demand for groundwater as source of irrigation water is growing higher as a results of increasing demand for increase in food production. Unlike the traditional method of farming where the farmer depends only on the rainfall hence, has to wait for a particular season before he can cultivate, the irrigation farming allows the farmer to cultivate all kinds of crops throughout the season and any were. It is likely that the use of groundwater for irrigation purpose will even increase with time due to the increase in population density and its demand for food security, negative impact of climate change on surface water bodies, increase in technology in farming, it closeness to the point of need, etc. The global statistics for groundwater irrigation in Table 2.2 also confirms this observation. For example, in India the groundwater-irrigated area increased by 500% since 1960 as they extract 160 kilometers of groundwater a year for irrigation (Shah, 2009; UNESCO 2004). About half of the vegetable producers in Ghana use groundwater for irrigation especially in the dry season (Cornish and Aidoo, 2000) and farmers in the Keta and the surrounding communities rely heavily of groundwater as source of irrigation