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G. A. Manful and Y. Opoku-Ankomah
parts of the basin, the impact on rudimentary onsite sanitation infrastructure may
be positive due to the fact that groundwater pollution risks may be minimized as
the distance between the base of pits and groundwater (and hence travel time for
pathogens) increases (Mahmud et al. 2007). Seasonal groundwater flooding of pits
become less frequent (Sherpa et al. 2014), but increased flooding will pose major
threats to sewage and septic systems that rely on water (Howard et al. 2016).
Various policy options could address the resilience of water and sanitation
services. In rural areas, where small water supplies continue to be the norm, key
policy decisions revolve around which technologies are acceptably resilient. Howard
et al. (2010) suggest that some, such as dug wells, are less resilient because they are
vulnerable to contamination, drought and/or long-term reduction in water volume,
and inability to prevent damage during flooding. Other technologies, such as raising
the wellheads of tubewells, may be more resilient, though they have yet to be
demonstrated to be effective.
Groundwater resources are widely expected to be less vulnerable to climate change
because of their inherent buffer against unpredictable rainfall, and are therefore
believed to form the basis of adaptation programs (Rockström et al. 2009 and JalifferVerne et al. 2015). In fact, groundwater resources are likely to be impacted as much
by increases in demand for groundwater as by changes to groundwater recharge
(Kundzewicz and Döll 2009). A caveat is that detection of and attribution to climate
change are difficult, given that surface and groundwater hydrology are governed by
multiple, interacting drivers and factors, such as land use change, water withdrawals,
and natural climate variability.
8 Conclusions
Studies have shown that the climate of the basin has been warming since the 1980s
when the temperature anomalies from the mean of the reference period of 1976–
2005 are examined for the entire historical period of 1951–2005, with temperatures
projected to increase by as much as 1.5 to 6 °C by the end of 2100 under mid-level
and high-level IPCC greenhouse gas forcing scenarios relative to 1976–2005. Precipitation has also varied, with the 1930s and 1950s being relatively wet and 1970s and
1980s being dry. There is some evidence of migration of isohyets southwards during
some decades, however, a trend has not been established with available information. There have been positive and negative anomalies in rainfall records without
any clear trend, even though positive anomalies appear to dominate in the recent
past. The onset of the rainy season has been shifting forward without any significant
change in rainfall amount, even though there is an increase in the number of extreme
rainfall events. Projections using IPCC scenarios show an increase in future extreme
rainfall events and an increase in periods of dry spells within rainy seasons, which
may be detrimental to rain-fed agriculture.
Although agricultural productivity is a principal driver out of the vicious cycle of
poverty within the Volta basin, all six riparian countries have agricultural systems
G. A. Manful and Y. Opoku-Ankomah
parts of the basin, the impact on rudimentary onsite sanitation infrastructure may
be positive due to the fact that groundwater pollution risks may be minimized as
the distance between the base of pits and groundwater (and hence travel time for
pathogens) increases (Mahmud et al. 2007). Seasonal groundwater flooding of pits
become less frequent (Sherpa et al. 2014), but increased flooding will pose major
threats to sewage and septic systems that rely on water (Howard et al. 2016).
Various policy options could address the resilience of water and sanitation
services. In rural areas, where small water supplies continue to be the norm, key
policy decisions revolve around which technologies are acceptably resilient. Howard
et al. (2010) suggest that some, such as dug wells, are less resilient because they are
vulnerable to contamination, drought and/or long-term reduction in water volume,
and inability to prevent damage during flooding. Other technologies, such as raising
the wellheads of tubewells, may be more resilient, though they have yet to be
demonstrated to be effective.
Groundwater resources are widely expected to be less vulnerable to climate change
because of their inherent buffer against unpredictable rainfall, and are therefore
believed to form the basis of adaptation programs (Rockström et al. 2009 and JalifferVerne et al. 2015). In fact, groundwater resources are likely to be impacted as much
by increases in demand for groundwater as by changes to groundwater recharge
(Kundzewicz and Döll 2009). A caveat is that detection of and attribution to climate
change are difficult, given that surface and groundwater hydrology are governed by
multiple, interacting drivers and factors, such as land use change, water withdrawals,
and natural climate variability.
8 Conclusions
Studies have shown that the climate of the basin has been warming since the 1980s
when the temperature anomalies from the mean of the reference period of 1976–
2005 are examined for the entire historical period of 1951–2005, with temperatures
projected to increase by as much as 1.5 to 6 °C by the end of 2100 under mid-level
and high-level IPCC greenhouse gas forcing scenarios relative to 1976–2005. Precipitation has also varied, with the 1930s and 1950s being relatively wet and 1970s and
1980s being dry. There is some evidence of migration of isohyets southwards during
some decades, however, a trend has not been established with available information. There have been positive and negative anomalies in rainfall records without
any clear trend, even though positive anomalies appear to dominate in the recent
past. The onset of the rainy season has been shifting forward without any significant
change in rainfall amount, even though there is an increase in the number of extreme
rainfall events. Projections using IPCC scenarios show an increase in future extreme
rainfall events and an increase in periods of dry spells within rainy seasons, which
may be detrimental to rain-fed agriculture.
Although agricultural productivity is a principal driver out of the vicious cycle of
poverty within the Volta basin, all six riparian countries have agricultural systems