Groundwater resources management in the Afram Plains area, Ghana

Abstract

A groundwater flow simulation model was developed using available hydrogeological data to describe groundwater flow in the Afram Plains area. A nonlinear optimization model was then developed and solved for the management of groundwater resources to meet irrigation and household needs. The objective was to maximize groundwater extraction from the shallow aquifers of the southern Voltaian Sedimentary Basin that underly the area, for irrigation activities. This would improve food security, raise the standard of living and ultimately help towards poverty alleviation in the rural communities that constitute the Afram Plains district. The calibrated flow model is in tandem with the general hydrochemical evolution of groundwater in the area and fits the observed data with about 98% degree of confidence. The study reveals that groundwater resources, if fully developed, may not be the limiting factor in the development of the irrigation industry, and has tremendous potential to meet current and future irrigation needs. Six groundwater management periods (January 2007-December 2013) were used for the study, with the quantity of irrigable land available, and the groundwater level drawdown as the main constraints that limit the maximization of groundwater extraction from wells for irrigation and household purposes. Maize was used as the single irrigation crop because maize appears to be the staple food and farmers are familiar with it in the area. It was determined from this pilot study, that profit from maize irrigation in the Afram Plains area could rise from US$ 301,000 in 2007 to over US$ 3.5million at the end of the last management period (2013) as irrigation practice is improved, and the economic strength to increase the acreage for irrigation improves. Even with these margins of profit, the drawdown constraint was not reached in any of the management periods. It is expected that recharge from the irrigation water would reclaim the lost hydraulic head. The single significant constraint was the amount of land area that could be developed for irrigation in the area. The profit obtained per unit cubic meter of water used also improved over the same management period.

Groundwater quality in some Voltaian and Birimian aquifers in northern Ghana—application of mulitvariate statistical methods and geographic information systems

“…3, cation exchange is amply implied in the relationships illustrated. Similar findings were noted in the southern Voltaian (Yidana 2008). Cation exchange activity is predominant in areas where clay size particles are available to provide large enough surface areas for such exchanges to occur.…”

“…A plot of these two indices against each other will indicate whether they increase in tandem or vary inversely. If the plot yields a straight line of slope = −1 and the data plot away from the origin, the suggestion is that cation exchange reactions probably play a significant role in the hydrochemistry (Jalali 2007, Yidana 2008. Where these reactions do not contribute significantly to the hydrochemistry, the data will plot close to the origin and the slope will be significantly different from −1.…”

Smallholder shallow groundwater irrigation development in the upper east region of Ghana

“…However, as has been found in many other parts of the world, groundwater use for agriculture and its potential may be underreported and unappreciated (Giordano 2005;Shah 2009). While information on groundwater availability and storage is in fact scarce (Yidana 2008), some recent assessments have suggested a positive view of the possibilities for groundwater use in agriculture in Ghana. Yidana (2008) and Yidana et al (2008a) find that groundwater in the Afram Plains has the potential to meet localized current and future community irrigation needs.…”

“…While information on groundwater availability and storage is in fact scarce (Yidana 2008), some recent assessments have suggested a positive view of the possibilities for groundwater use in agriculture in Ghana. Yidana (2008) and Yidana et al (2008a) find that groundwater in the Afram Plains has the potential to meet localized current and future community irrigation needs. According to Akudago et al (2009), there is enough groundwater in Northern Ghana to support irrigation provided that careful management practices of the aquifer system are adhered to.…”

Spatial and temporal variability of groundwater quality of an Algerian aquifer: the case of Soummam Wadi

“…According to many authors (Hem 1985, Bricker andJones 1995), water chemical composition is controlled by many factors, which include composition of precipitation (Dzhamalov and Zlobina 1995), mineralogy of river basins (Oyarzûn et al 2013), aquifers (Kortelainen and Karhu 2009), climate (Okkonen and Kløve 2012) and topography (Ielpo et al 2012). Those factors may combine to create various types of water with a change in composition over space and time (Yidana 2008). The chemical composition of groundwater is a function of the chemical composition of the aquifer host rocks, flow conditions and residence time in the aquifer (Back and Hanshaw 1971).…”