produced to which the specific prices are applied
per consumption range, hence the use of average
prices.
4 Conclusions
The objective of this study was to estimate the
economic value of the benefit of avoiding the offsite costs imposed by erosion on the hydroelectric production of the Lagdo Dam, providing an
example of a water-soil-energy nexus (Rasul
2014). Indeed, through erosion and sedimentation, upstream activities occurring in different
biophysical components of the watershed generate downstream externalities. The damage
function approach was carried out to measure the
value of the hydroelectric potential loss (the
marginal damage being the quantity of kilowatt
hours lost) induced by the deposition of an
additional cubic meter of sediment in the reservoir. The results show that due to erosion in the
Lake Lagdo watershed, a sediment volume of
about 40.80 million cubic meters is carried into
the lower lake every year. On the basis of this
observation made by MEADEN, the results show
that the deposit of this quantity of sediment in the
Lagdo Dam deprives the lake of an equivalent
potential capacity of usable water for the production of electricity. Such a potential loss of
water would cause a potential annual loss of
hydroelectric power of about 2.4 million kWh
per year. Monetary valuation based on kWh
prices in the area shows that such annual loss of
potential energy due to sedimentation is equivalent to 156 million CFA francs (USD
279,274.73) per year. In other words, the service
provided by the adoption of anti-erosion measures by farmers such as non-tillage practices,
mulching, contour and alley farming, and terrace
construction while growing annual crops in the
catchment area is estimated at 156 million CFA
francs per year. This paper contributes to the
monetary evaluation of an environmental service
of agriculture in Northern Cameroon.
One very clear notion that comes from this
research is the need to develop more damage
estimation techniques to aid in the cost analysis.
This would involve developing standardized
tools for estimating average and marginal costs
of erosion on certain activities. These tools could
be employed by conservation agents with a
limited amount of cost/damage information.
Exploration of other erosion damages is also
needed both for general and specific knowledge.
Erosion impacts on irrigation systems, industrial
water use, flood control, fish and wildlife populations, and recreation choices are currently
undocumented. For the study area, a much better
understanding of the distribution of erosion
occurrences and damages is needed to help
accurately project total benefits from conservation projects. Better reporting by producers of
physical damages would also greatly help in the
projection of specific off-site benefits from soil
conservation projects.
Acknowledgements The authors thank the coordination
of the Water-Soil-Tree Project in Garoua, for the financial
support and the provision of materials. The authors also
would like to thank the Study Mission for Planning and
Development of the Northern Province without whose
support this work could not have been completed.
References
Abou A, Hofs J-L, Mergeai G (2006) Relever les défis
environnementaux pour les filières co-tonnières
d’Afrique de l’Ouest et du Centre. Biotechnologie,
Agronomie, Société Et Environ-Nement 10:351–359
Aylward B (1998) Economic valuation of the downstream
hydrological effects of land use change: large hydroelectric reservoirs. Unpublished Ph.D.diss., Fletcher
School of Law and Diplomacy, Medford
Aznar O, Perrier-Cornet P (2003) Les services environnementaux: diversité des conceptions et réalité des
contours. Economie Rurale 273–274:153–168
Baboule ZB, Roose E, Sanon K, Waech F, Ziem BBA
(1993) Effets des techniques culturales sur le ruissellement, l’érosion et la production de coton et de
maïs sur un sol ferrugineux tropical sableux.
Recherche de systèmes de culture intensifs et durable
en région soudanienne au Nord Cameroun . Cah
Orstom Sér Pédol 27:309–325
Barbier B (1996) The economics of soil erosion: theory,
methodology and examples. Discussion papers in
environmental economics and environmental management. University of York, Heslington, UK
Bekele W (2003) Economics of soil and water conservation: theory and empirical application to subsistence
farming in the eastern ethiopian highlands. Doctoral
104
D. Y. Ngondjeb and E. Ayuk
per consumption range, hence the use of average
prices.
4 Conclusions
The objective of this study was to estimate the
economic value of the benefit of avoiding the offsite costs imposed by erosion on the hydroelectric production of the Lagdo Dam, providing an
example of a water-soil-energy nexus (Rasul
2014). Indeed, through erosion and sedimentation, upstream activities occurring in different
biophysical components of the watershed generate downstream externalities. The damage
function approach was carried out to measure the
value of the hydroelectric potential loss (the
marginal damage being the quantity of kilowatt
hours lost) induced by the deposition of an
additional cubic meter of sediment in the reservoir. The results show that due to erosion in the
Lake Lagdo watershed, a sediment volume of
about 40.80 million cubic meters is carried into
the lower lake every year. On the basis of this
observation made by MEADEN, the results show
that the deposit of this quantity of sediment in the
Lagdo Dam deprives the lake of an equivalent
potential capacity of usable water for the production of electricity. Such a potential loss of
water would cause a potential annual loss of
hydroelectric power of about 2.4 million kWh
per year. Monetary valuation based on kWh
prices in the area shows that such annual loss of
potential energy due to sedimentation is equivalent to 156 million CFA francs (USD
279,274.73) per year. In other words, the service
provided by the adoption of anti-erosion measures by farmers such as non-tillage practices,
mulching, contour and alley farming, and terrace
construction while growing annual crops in the
catchment area is estimated at 156 million CFA
francs per year. This paper contributes to the
monetary evaluation of an environmental service
of agriculture in Northern Cameroon.
One very clear notion that comes from this
research is the need to develop more damage
estimation techniques to aid in the cost analysis.
This would involve developing standardized
tools for estimating average and marginal costs
of erosion on certain activities. These tools could
be employed by conservation agents with a
limited amount of cost/damage information.
Exploration of other erosion damages is also
needed both for general and specific knowledge.
Erosion impacts on irrigation systems, industrial
water use, flood control, fish and wildlife populations, and recreation choices are currently
undocumented. For the study area, a much better
understanding of the distribution of erosion
occurrences and damages is needed to help
accurately project total benefits from conservation projects. Better reporting by producers of
physical damages would also greatly help in the
projection of specific off-site benefits from soil
conservation projects.
Acknowledgements The authors thank the coordination
of the Water-Soil-Tree Project in Garoua, for the financial
support and the provision of materials. The authors also
would like to thank the Study Mission for Planning and
Development of the Northern Province without whose
support this work could not have been completed.
References
Abou A, Hofs J-L, Mergeai G (2006) Relever les défis
environnementaux pour les filières co-tonnières
d’Afrique de l’Ouest et du Centre. Biotechnologie,
Agronomie, Société Et Environ-Nement 10:351–359
Aylward B (1998) Economic valuation of the downstream
hydrological effects of land use change: large hydroelectric reservoirs. Unpublished Ph.D.diss., Fletcher
School of Law and Diplomacy, Medford
Aznar O, Perrier-Cornet P (2003) Les services environnementaux: diversité des conceptions et réalité des
contours. Economie Rurale 273–274:153–168
Baboule ZB, Roose E, Sanon K, Waech F, Ziem BBA
(1993) Effets des techniques culturales sur le ruissellement, l’érosion et la production de coton et de
maïs sur un sol ferrugineux tropical sableux.
Recherche de systèmes de culture intensifs et durable
en région soudanienne au Nord Cameroun . Cah
Orstom Sér Pédol 27:309–325
Barbier B (1996) The economics of soil erosion: theory,
methodology and examples. Discussion papers in
environmental economics and environmental management. University of York, Heslington, UK
Bekele W (2003) Economics of soil and water conservation: theory and empirical application to subsistence
farming in the eastern ethiopian highlands. Doctoral
104
D. Y. Ngondjeb and E. Ayuk