326
B. Lèye et al.
Burkina Faso, as a pilot site representing a large number of small reservoirs in the
Volta basin subject to the same constraints. Once the water balance was determined, it
became possible to characterize the functioning of the Boura hydrosystem at different
time steps in the filling and destocking cycle. Findings are that of the water mobilized
by the reservoir (9.23 million m
3 ), 60% evaporates, 24% infiltrates and 19% is levied
to meet user demands, especially irrigation. The load factor went from 2.3 for the
2012–2013 season to only 0.7 for the following (2013–2014) season. This indicates
that even over a short period, the water regime of the Boura dam is greatly variable,
mainly driven by variations in input controlled by rainfall. Calibrated hydrologic
models based on these data are then used to make projections of inputs to the Boura
reservoir, of agricultural water demand and of the functioning of the Boura reservoir
under different scenarios of climate change and socioeconomic development. The
conclusion is that it would be difficult to satisfy irrigation demands by considering
only the surface reservoir as a source of supply, and that the aquifer must also be
considered a water source to meet demand.
4.3.4 Supplemental Irrigation
In the Sahelian countries, farmers, the scientific community, governments and their
partners seek innovative agricultural practices to respond to periods of drought. The
thesis work of Zongo (2016) considers the adoption of agricultural innovations in
the Sahelian and Sudano-Sahelian areas of Burkina Faso, including the practice of
supplementing irrigation from individual basins on farms. Complementary irrigation
delivers water to crops during the long periods of drought during the rainy season.
This is runoff water stored in small basins built near crop fields (Fig. 16). The practice increases maize yield by 1.08 T/ha (88.3%) compared to a lack of supplemental
irrigation. About 78.4% of households believe that supplemental irrigation is an interesting option to mitigate the effects of drought periods on agricultural production.
The study, however, notes the need to establish a system of financial credit to enable
such a scheme.
4.3.5 Agriculture and Climate Information
Several models have been developed to generate and communicate climate information to different users according to their needs. The source of information is seasonal
climate forecasts based on meteorological data. The most relevant variables used to
create forecasts are the start of heavy rains, the beginning of sowing, the end of the
rainy season and the distribution of rainfall within the season (intra-seasonal distribution). The thesis of Zongo (2016) evaluates the impact of climate information on
maize and sorghum production in the Bam province in the Sahel region during the
2013–2014 and 2014–2015 agricultural seasons. It compares the dates of seedlings,
yields and contribution to cereal requirement from experimental to control plots and
shows that producers use the sowing date information in the experimental group to
B. Lèye et al.
Burkina Faso, as a pilot site representing a large number of small reservoirs in the
Volta basin subject to the same constraints. Once the water balance was determined, it
became possible to characterize the functioning of the Boura hydrosystem at different
time steps in the filling and destocking cycle. Findings are that of the water mobilized
by the reservoir (9.23 million m
3 ), 60% evaporates, 24% infiltrates and 19% is levied
to meet user demands, especially irrigation. The load factor went from 2.3 for the
2012–2013 season to only 0.7 for the following (2013–2014) season. This indicates
that even over a short period, the water regime of the Boura dam is greatly variable,
mainly driven by variations in input controlled by rainfall. Calibrated hydrologic
models based on these data are then used to make projections of inputs to the Boura
reservoir, of agricultural water demand and of the functioning of the Boura reservoir
under different scenarios of climate change and socioeconomic development. The
conclusion is that it would be difficult to satisfy irrigation demands by considering
only the surface reservoir as a source of supply, and that the aquifer must also be
considered a water source to meet demand.
4.3.4 Supplemental Irrigation
In the Sahelian countries, farmers, the scientific community, governments and their
partners seek innovative agricultural practices to respond to periods of drought. The
thesis work of Zongo (2016) considers the adoption of agricultural innovations in
the Sahelian and Sudano-Sahelian areas of Burkina Faso, including the practice of
supplementing irrigation from individual basins on farms. Complementary irrigation
delivers water to crops during the long periods of drought during the rainy season.
This is runoff water stored in small basins built near crop fields (Fig. 16). The practice increases maize yield by 1.08 T/ha (88.3%) compared to a lack of supplemental
irrigation. About 78.4% of households believe that supplemental irrigation is an interesting option to mitigate the effects of drought periods on agricultural production.
The study, however, notes the need to establish a system of financial credit to enable
such a scheme.
4.3.5 Agriculture and Climate Information
Several models have been developed to generate and communicate climate information to different users according to their needs. The source of information is seasonal
climate forecasts based on meteorological data. The most relevant variables used to
create forecasts are the start of heavy rains, the beginning of sowing, the end of the
rainy season and the distribution of rainfall within the season (intra-seasonal distribution). The thesis of Zongo (2016) evaluates the impact of climate information on
maize and sorghum production in the Bam province in the Sahel region during the
2013–2014 and 2014–2015 agricultural seasons. It compares the dates of seedlings,
yields and contribution to cereal requirement from experimental to control plots and
shows that producers use the sowing date information in the experimental group to