314
B. Lèye et al.
et al. 2019). In the same area, starting from the year 1998, dry spells of more than
16 days have been observed (Fig. 4c). In the Sahelo-Sudanian zone, the length of
dry spells are somewhat stable and generally do not exceed 15 days (Fig. 4d), with
a number of dry spells between three and four (Fig. 4b). Nevertheless, from 1984 to
2013, there was more variability (8–17 days) in the duration of dry spells.
As compared to the 1986–2005 IPCC baseline, climate projections predict a
decrease in rainfall of 3.4% in 2025 and 7.3% in 2050. The decrease in rainfall will
be coupled with high interannual and seasonal variability. Rainfall in July, August
and September will decrease by 20–30%, while rainfall in November will experience
an increase from 60 to 80% (MECV/BF 2007).
2.2 Surface Water
Surface waters consist of streams, lakes, ponds and artificial mobilization of surface
water, such as is created by dams. The storable potential of these water reservoirs in
Burkina Faso is estimated at about 5 billion m
3 , of which 0.8 billion m
3 represents
the storage capacity of small dams (Leemhuis et al. 2009). In the Sahelian zone,
Class A pan measurements have been used to estimate daily evaporation at 7–8 mm
during the rainy season and can reach 10 mm during the dry season, with an average
of 2,920 mm per year, far greater than the cumulative annual rainfall (Niang 2006).
Daily temperatures vary from 16 to 45 °C over the year.
Reservoirs are made up of 56% dams, 31% artificial lakes, 12% ponds and 1%
natural lakes (Naturama 2015). The country has a hydrometric network of about 95
functional stations that realize varying amounts of the water height, volume and flow.
According to the Ministry of Agriculture and Hydraulics, Burkina Faso had 1,806
surface water reservoirs in 2015 (MEA/BF 2015). Furthermore, the National Program
for Environmental Information Management, which is responsible for improving
the relevance, quality and availability of environmental information, developed a
database in 1999 that lists 1,457 dams throughout the country (MEA/BF 2015).
Nearly half of these dams were built between 1974 and 1987, a period that coincides
with the severe droughts of the 1970s and 1980s, rapid population growth and the
promotion of small-scale irrigation in West Africa.
The use of small basins has focused on domestic water use, manufacture of dried
clay bricks and livestock watering. The water from these ponds is rarely used for
supplemental irrigation, but they do help mitigate the negative effects of droughts and
act as flood protection structures. They also contribute to the recharge of groundwater
(Koussoubé 1996). Figure 5 shows the map of water reservoirs and watersheds across
the country.
Several recent studies have recorded climate parameters (rainfall, temperature,
evapotranspiration) and surface water resource in Burkina Faso (Op de Hipt et al.
2018). The interannual variation of the mean temperature is illustrated in Fig. 6.
Climate models projections indicate an increase in average temperatures of 0.8 °C
by 2025 and 1.7 °C by 2050 (MECV/BF 2007) as compared to the 1986–2005
B. Lèye et al.
et al. 2019). In the same area, starting from the year 1998, dry spells of more than
16 days have been observed (Fig. 4c). In the Sahelo-Sudanian zone, the length of
dry spells are somewhat stable and generally do not exceed 15 days (Fig. 4d), with
a number of dry spells between three and four (Fig. 4b). Nevertheless, from 1984 to
2013, there was more variability (8–17 days) in the duration of dry spells.
As compared to the 1986–2005 IPCC baseline, climate projections predict a
decrease in rainfall of 3.4% in 2025 and 7.3% in 2050. The decrease in rainfall will
be coupled with high interannual and seasonal variability. Rainfall in July, August
and September will decrease by 20–30%, while rainfall in November will experience
an increase from 60 to 80% (MECV/BF 2007).
2.2 Surface Water
Surface waters consist of streams, lakes, ponds and artificial mobilization of surface
water, such as is created by dams. The storable potential of these water reservoirs in
Burkina Faso is estimated at about 5 billion m
3 , of which 0.8 billion m
3 represents
the storage capacity of small dams (Leemhuis et al. 2009). In the Sahelian zone,
Class A pan measurements have been used to estimate daily evaporation at 7–8 mm
during the rainy season and can reach 10 mm during the dry season, with an average
of 2,920 mm per year, far greater than the cumulative annual rainfall (Niang 2006).
Daily temperatures vary from 16 to 45 °C over the year.
Reservoirs are made up of 56% dams, 31% artificial lakes, 12% ponds and 1%
natural lakes (Naturama 2015). The country has a hydrometric network of about 95
functional stations that realize varying amounts of the water height, volume and flow.
According to the Ministry of Agriculture and Hydraulics, Burkina Faso had 1,806
surface water reservoirs in 2015 (MEA/BF 2015). Furthermore, the National Program
for Environmental Information Management, which is responsible for improving
the relevance, quality and availability of environmental information, developed a
database in 1999 that lists 1,457 dams throughout the country (MEA/BF 2015).
Nearly half of these dams were built between 1974 and 1987, a period that coincides
with the severe droughts of the 1970s and 1980s, rapid population growth and the
promotion of small-scale irrigation in West Africa.
The use of small basins has focused on domestic water use, manufacture of dried
clay bricks and livestock watering. The water from these ponds is rarely used for
supplemental irrigation, but they do help mitigate the negative effects of droughts and
act as flood protection structures. They also contribute to the recharge of groundwater
(Koussoubé 1996). Figure 5 shows the map of water reservoirs and watersheds across
the country.
Several recent studies have recorded climate parameters (rainfall, temperature,
evapotranspiration) and surface water resource in Burkina Faso (Op de Hipt et al.
2018). The interannual variation of the mean temperature is illustrated in Fig. 6.
Climate models projections indicate an increase in average temperatures of 0.8 °C
by 2025 and 1.7 °C by 2050 (MECV/BF 2007) as compared to the 1986–2005