258
C. Faye et al.
2 Description of the Study Area
The Republic of Senegal, located on the extreme western tip of the African continent,
covers an area of 196,722 km
2 with an estimated population of 16,200,000. With
700 km of Atlantic coastline, Senegal is located between 12.5° and 16.5° North
latitude and 12° and 17° West longitude. The variation in the quantity and frequency
of rainfall from South to North creates three climatic zones: southern Sudanian,
northern Sudanian and Sahelian. Each zone has two sections: coastal and continental
zone (Faye et al. 2017).
Senegal has a Sudano-Sahelian tropical climate with annual rainfall between about
1,250 mm in the South to just over 200 mm in the North. There is a rainy season
and dry season: the former corresponds to the monsoon period, extending roughly
from June to October with a peak in August-September. The rain in this period
varies depending on the latitude. The dry season lasts from November to June and
is characterized by hot, dry wind, known as “the Harmattan.”
Senegal’s surface and groundwater resources are rich, with heterogeneous soils
and a dense hydrographic network. Most surface water reserves are located in
the Senegal and Gambia river basins (Sané 2015). Groundwater consists of four
major aquifer systems: shallow, intermediate, deep and basement (CONGAD 2009).
Senegal currently has sufficient water resources to meet demand, but it is threatened
by drought and climate change.
3 Methodology
3.1 Characterizing Climate Change Impacts on Water
Resources
3.1.1 Context
Climate change is defined by trends in the global mean sea and atmospheric temperatures, variation and quantity of rainfall, and increase of the magnitude and frequency
of natural disasters and extreme events (drought, floods, etc.) (IPCC 2007). Global
warming, combined with increased variability of rainfall, is driving an upsurge
in extreme events, including floods and low flows, which in turn will increase in
frequency and in intensity across the African continent. Various studies reveal the
evolution of flows in rivers and their impacts on natural and human ecosystems,
subject to the hydro-climatic conditions in various regions (Faye et al. 2015a).
The African continent is among the most impacted by climate fluctuations on
water resources (Kanohin et al. 2009). Several studies carried out in West and Central
Africa have shown a decrease in surface and groundwater flows since the 1970s as a
result of a decrease in rainfall (Dione 1996; Sow 2007; Faye 2013; Faye et al. 2015b),
but an increase in flows (Niang et al. 2008; Ali and Lebel 2009; Ozer et al. 2009;
C. Faye et al.
2 Description of the Study Area
The Republic of Senegal, located on the extreme western tip of the African continent,
covers an area of 196,722 km
2 with an estimated population of 16,200,000. With
700 km of Atlantic coastline, Senegal is located between 12.5° and 16.5° North
latitude and 12° and 17° West longitude. The variation in the quantity and frequency
of rainfall from South to North creates three climatic zones: southern Sudanian,
northern Sudanian and Sahelian. Each zone has two sections: coastal and continental
zone (Faye et al. 2017).
Senegal has a Sudano-Sahelian tropical climate with annual rainfall between about
1,250 mm in the South to just over 200 mm in the North. There is a rainy season
and dry season: the former corresponds to the monsoon period, extending roughly
from June to October with a peak in August-September. The rain in this period
varies depending on the latitude. The dry season lasts from November to June and
is characterized by hot, dry wind, known as “the Harmattan.”
Senegal’s surface and groundwater resources are rich, with heterogeneous soils
and a dense hydrographic network. Most surface water reserves are located in
the Senegal and Gambia river basins (Sané 2015). Groundwater consists of four
major aquifer systems: shallow, intermediate, deep and basement (CONGAD 2009).
Senegal currently has sufficient water resources to meet demand, but it is threatened
by drought and climate change.
3 Methodology
3.1 Characterizing Climate Change Impacts on Water
Resources
3.1.1 Context
Climate change is defined by trends in the global mean sea and atmospheric temperatures, variation and quantity of rainfall, and increase of the magnitude and frequency
of natural disasters and extreme events (drought, floods, etc.) (IPCC 2007). Global
warming, combined with increased variability of rainfall, is driving an upsurge
in extreme events, including floods and low flows, which in turn will increase in
frequency and in intensity across the African continent. Various studies reveal the
evolution of flows in rivers and their impacts on natural and human ecosystems,
subject to the hydro-climatic conditions in various regions (Faye et al. 2015a).
The African continent is among the most impacted by climate fluctuations on
water resources (Kanohin et al. 2009). Several studies carried out in West and Central
Africa have shown a decrease in surface and groundwater flows since the 1970s as a
result of a decrease in rainfall (Dione 1996; Sow 2007; Faye 2013; Faye et al. 2015b),
but an increase in flows (Niang et al. 2008; Ali and Lebel 2009; Ozer et al. 2009;