Rainfall variability and groundwater availability for irrigation in Sub-Saharan Africa: evidence from the Niayes region of Senegal

Faye, Amy and Msangi, Siwa (2018): Rainfall variability and groundwater availability for irrigation in Sub-Saharan Africa: evidence from the Niayes region of Senegal.

Abstract

Recent research on climate change, within the context of Sub-Saharan Africa, has shown the vulnerability of groundwater resources to climate change and variability. In Senegal, agriculture is among the most important users of groundwater resources, especially in the northern coastal area called ‘Niayes’ where farmers practice irrigated agriculture and use almost exclusively the quarternary sand aquifer for their irrigation needs during the dry season – which is the main growing period. However, in Senegal, irrigated agriculture, particularly that of horticultural crops, mostly grown in the Niayes, has attracted less research attention in terms of studies focused on climate change or variability, compared to staple-growing rainfed regions. In the Niayes region, farmers grow most of Senegal’s horticultural production. Combined with human use of water resources, climate variability may threaten future irrigation water availability in the area. This paper uses an integrated hydroeconomic model and a rainfall generator to evaluate the impact of rainfall variability on irrigation water availability and simulate its implications on producers’ responses and groundwater management policy measures. Results show that groundwater availability is diminishing over time, resulting in higher water table depth and smaller water withdrawals by farmers who will tend to decrease the area allocated to crops and favor the higher-valued crops. These trends are accelerated under a drier climate regime. A taxation policy to stabilize the aquifer would induce a reduction of the area under cultivation and have negative implications on revenues. Supply-side measures to enhance recharge may not be technically or financially feasible. This suggests that Senegal needs to develop groundwater management options that favor sustainable use of agricultural water resources without hindering national horticultural production.

• Item Type: MPRA Paper
• Language: English
• Keywords: Agriculture; irrigation; rainfall variability; hydro-economic modeling; groundwater management; Senegal.
• Subjects: C - Mathematical and Quantitative Methods > C6 - Mathematical Methods ; Programming Models ; Mathematical and Simulation Modeling

References

Aguiar, L. A., Garneau, M., Lézine, A.-M., & Maugis, P. (2010). Évolution de la nappe des sables quaternaires dans la région des Niayes du Sénégal (1958-1994) : relation avec le climat et les impacts anthropiques. Science et Changements Planétaires / Sécheresse, 21(2), 97–104. https://doi.org/10.1684/SEC.2010.0237

Aidam, P. W. (2015). The impact of water-pricing policy on the demand for water resources by farmers in Ghana. Agricultural Water Management, 158, 10–16. https://doi.org/10.1016/j.agwat.2015.04.007

Berbel, J., Calatrava, J., & Garrido, A. (2007). Water Pricing and Irrigation : A Review of the European Experience, 295–327.

Berbel, J., & Gomez-Limon, J. A. (2000). The impact of water-pricing policy in Spain : an analysis of three irrigated areas. Agricultural Water Management, 43, 219–238.

Blanco-Gutiérrez, I., Varela-Ortega, C., & Purkey, D. R. (2013). Integrated assessment of policy interventions for promoting sustainable irrigation in semi-arid environments: A hydro-economic modeling approach. Journal of Environmental Management, 128, 144–160. https://doi.org/10.1016/J.JENVMAN.2013.04.037

Bontemps, C., & Couture, S. (2002). Irrigation water demand for the decision maker. Environment and Development Economics, 7(04), 643–657. https://doi.org/10.1017/S1355770X02000396

Booker, J. F. (1995). Hydrologic and economic impacts of drought under alternatwe policy responses. Journal of the American Water Resources Association, 31(5), 889–906. https://doi.org/10.1111/j.1752-1688.1995.tb03409.x

Booker, J. F., Howitt, R. E., MICHELSEN, A. M., & YOUNG, R. A. (2012). Economics and the modeling of water resources and policies. Natural Resource Modeling, 25(1), 168–218. https://doi.org/10.1111/j.1939-7445.2011.00105.x

Brouwer, C., Goffeau, A., & Heibloem, M. (1985). Irrigation Water Management: Training Manual No. 1 - Introduction to Irrigation. Retrieved April 6, 2018, from http://www.fao.org/docrep/R4082E/R4082E00.htm

Brouwer, R., & Hofkes, M. (2008). Integrated hydro-economic modelling: Approaches, key issues and future research directions. https://doi.org/10.1016/j.ecolecon.2008.02.009

Burt, O. R. (1964). Optimal Resource Use Over Time with an Application to Ground Water. Management Science, 11(1), 80–93. https://doi.org/10.1287/mnsc.11.1.80

Burt, O. R. (1966). Economic Control of Groundwater Reserves. Journal of Farm Economics, 48(3), 632. https://doi.org/10.2307/1236865

Burt, O. R. (1967). Temporal allocation of groundwater. Water Resources Research, 3(1), 45–56. https://doi.org/10.1029/WR003i001p00045 Carvalho, D. F., Neto, D. H. O., Felix, L. F., Guerra, J. G.

M., & Salvador, C. A. (2016). Yield, water use efficiency, and yield response factor in carrot crop under different irrigation depths. Ciência Rural, 46(7), 1145–1150. https://doi.org/https://dx.doi.org/10.1590/0103-8478cr20150363

Dasylva, S., & Cosandey, C. (2005). L’exploitation de la Nappe des Sables Quaternaires pour l’alimentation en eau potable de Dakar : une offre compromise par l’insuffisance de la recharge pluviométrique. Géocarrefour, 80(4), 349–358. https://doi.org/10.4000/geocarrefour.1385

Doorenbos, J., & Kassam, A. H. (1979). Yield response to water. FAO Irrigation and Drainage, Paper 33. Rome.

El Faid, S. (1999). Étude géochimiques et isotopique des transferts d’eau et de solutés dans la zone non saturée de la nappe des sables quaternaires de Louga (nord Sénégal), recharge et paléorecharge. Université Cheikh Anta Diop de Dakar.

Esteban, E., & Albiac, J. (2011). Groundwater and ecosystems damages: Questioning the Gisser–Sánchez effect. Ecological Economics, 70(11), 2062–2069. https://doi.org/10.1016/J.ECOLECON.2011.06.004

Esteve, P., Varela-Ortega, C., Blanco-Gutiérrez, I., & Downing, T. E. (2015). A hydro-economic model for the assessment of climate change impacts and adaptation in irrigated agriculture. Ecological Economics, 120, 49–58. https://doi.org/10.1016/J.ECOLECON.2015.09.017

FALL, M. D. (2012). Modélisation hydrogéologique conceptuelle de la nappe des sables quaternaires du littoral nord du Sénégal entre Dakar et Saint-Louis. International Institute for Water and Environmental Engineering.

Fare, Y., Dufumier, M., Loloum, M., Miss, F., Pouye, A., Khastalani, A., & Fall, A. (2017). Analysis and Diagnosis of the Agrarian System in the Niayes Region, Northwest Senegal (West Africa). Agriculture, 7(7), 59. https://doi.org/10.3390/agriculture7070059

Faye, J., Ba, C. O., Dieye, P. N., & Dansoko, M. (2007). Implications structurelles de la libéralisation sur l’agriculture et le developpement rural au Sénégal (1950 – 2006).

Faye, S. (1995). Modélisation hydrodynamique des nappes du littoral Nord entre Cayar et St. Louis. Impact des futurs prélèvements envisagés dans le cadre de l’approvisionnement en eau de Dakar et de ses environs. Université Cheikh Anta Diop de Dakar.

Gaye, C. B. (1990). Étude isotopique et géochimique du mode de recharge par les pluies et par décharge évaporatoire des aquifères libres sous climat semi-aride au nord du Sénégal. Université Cheikh Anta Diop de Dakar.

Giordano, M. (2006). Agricultural groundwater use and rural livelihoods in sub-Saharan Africa: A first-cut assessment. Hydrogeology Journal, 14(3), 310–318. https://doi.org/10.1007/s10040-005-0479-9

Gisser, M., & Sánchez, D. A. (1980). Competition versus optimal control in groundwater pumping. Water Resources Research, 16(4), 638–642. https://doi.org/10.1029/WR016i004p00638

Graveline, N. (2016). Economic calibrated models for water allocation in agricultural production: A review. Environmental Modelling & Software, 81(C), 12–25. https://doi.org/10.1016/j.envsoft.2016.03.004

Griffin, R. C. (2006). Water resource economics : the analysis of scarcity, policies, and projects. MIT Press. Retrieved from https://mitpress.mit.edu/books/water-resource-economics

Harou, J. J., Pulido-Velazquez, M., Rosenberg, D. E., Medellín-Azuara, J., Lund, J. R., & Howitt, R. E. (2009). Hydro-economic models: Concepts, design, applications, and future prospects. Journal of Hydrology, 375, 627–643. https://doi.org/10.1016/j.jhydrol.2009.06.037

Heckelei, T., & Britz, W. (2005). Models Based on Positive Mathematical Programming: State of the Art and Further Extensions. Retrieved from http://ageconsearch.umn.edu/bitstream/234607/2/Heckelei et al 2005 Models Based on Positive Mathematical Programming- State of the Art and Further Extensions.pdf

Heidecke, C. (2010). Economic analysis of water use and management in the Middle Drâa valley in Morocco. Rheinischen Friedrich-Wilhelms-Universität zu Bonn. Retrieved from http://hss.ulb.uni-bonn.de/2010/2022/2022.pdf

Howitt, R. E. (1995). Positive Mathematical Programming. American Journal of Agricultural Economics, 77, 329–342.

Howitt, R. E., Medellín-Azuara, J., MacEwan, D., & Lund, J. R. (2012). Calibrating disaggregate economic models of agricultural production and water management. Environmental Modelling & Software, 38, 244–258. https://doi.org/10.1016/j.envsoft.2012.06.013

Howitt, R. E., Msangi, S., Reynaud, A., & Knapp, K. (2002). Using Polynomial Approximations to Solve Stochastic Dynamic Programming Problems: or A " Betty Crocker " Approach to SDP. Retrieved from https://pdfs.semanticscholar.org/f2cd/69724b5fdf70da6011f4f74255a8fee47fac.pdf

Hubbard, T., & Saglam, Y. (n.d.). Solution to Numerical Dynamic Programming Problems 1 Common Computational Approaches. Retrieved from http://home.uchicago.edu/hickmanbr/uploads/chapter5_2.pdf

Hughes, D. A., Jewitt, G., Mahé, G., Mazvimavi, D., & Stisen, S. (2015). A review of aspects of hydrological sciences research in Africa over the past decade. Hydrological Sciences Journal, 1–15. https://doi.org/10.1080/02626667.2015.1072276

Jalloh, A., Faye, M. D., Roy-Macauley, H., Sérémé, P., Zougmoré, R., Thomas, T. S., & Nelson, G. C. (2013). Overview. In Chapter 1 In West African Agriculture and Climate Change: A comprehensive Analysis (pp. 1-37). https://doi.org/http://dx.doi.org/10.2499/9780896292048

Jiing, G., You, -Yun, & Ringler, C. (2010). Hydro-Economic Modeling of Climate Change Impacts in Ethiopia. Retrieved from http://ebrary.ifpri.org/utils/getfile/collection/p15738coll2/id/868/filename/869.pdf

Johnson, A. I. (1967). Specific Yield Compilation of Specific Yields for Various Materials-- Hydrologic properties of earth materials. Geological Survey Water-Supply Paper 1662-D. Retrieved from https://pubs.usgs.gov/wsp/1662d/report.pdf

Judd, K. L. (1998). Numerical methods in economics. MIT Press.

Kim, C., Moore, M. R., Hanchar, J. J., & Nieswiadomy, M. (1989). A dynamic model of adaptation to resource depletion: theory and an application to groundwater mining. Journal of Environmental Economics and Management, 17(1), 66–82. https://doi.org/10.1016/0095-0696(89)90037-5

Kim, C. S., Fuglie, K., Wallander, S., & Wechsler, S. (2015). Endogenous technical change and groundwater management: Revisiting the Gisser-Sanchez paradox. In Agricultural & Applied Economics Association (pp. 1–33). Retrieved from http://ageconsearch.umn.edu/bitstream/205350/2/2015_May 27_AAEA.pdf

Knapp, K. C., & Olson, L. J. (1995). The Economics of Conjunctive Groundwater Management with Stochastic Surface Supplies. Journal of Environmental Economics and Management, 28(3), 340–356. https://doi.org/10.1006/JEEM.1995.1022

Koundouri, P. (2004). Current Issues in the Economics of Groundwater Resource Management. Journal of Economic Surveys, 18(5), 703–740. https://doi.org/10.1111/j.1467-6419.2004.00234.x

Kumar, C. P. (2012). Climate Change and Its Impact on Groundwater Resources. International Journal of Engineering and Science, 1(5), 2278–4721. Retrieved from www.researchinventy.com

Leary, N. A. (1999). A Framework for Benefit-Cost Analysis of Adaptation to Climate Change and Climate Variability. Mitigation and Adaptation Strategies for Global Change, 4(3/4), 307–318. https://doi.org/10.1023/A:1009667706027

Mckee, T. B., Doesken, N. J., & Kleist, J. (1993). The relationship of drought frequency and duration to time scales. Eighth Conference on Applied Climatology, 17–22. Retrieved from http://www.droughtmanagement.info/literature/AMS_Relationship_Drought_Frequency_Duration_Time_Scales_1993.pdf

Medellín-Azuara, J., Howitt, R., & Lund, J. (2010). Hydro- Economic Modeling to Assess Climate Impact and Adaptation for Agriculture in California. Retrieved April 5, 2018, from http://www.adaptation-undp.org/resources/document/hydro-economic-modeling-assess-climate-impact-and-adaptation- agriculture-0

Meinzen-dick, R., Janssen, M. A., Rao, R. K., & Theis, S. (2017). Playing Games to Save Water : Collective Action Games for Groundwater Management in India. CBIE Working Paper Series, CBIE-2017-.

Ministry of Agriculture and Rural Equipment. (2013). Recensement de l’horticulture et Mise en place d’un système permanent de statistiques horticoles dans la zone des Niayes, Résultats du recensement. Retrieved from http://www.paden-senegal.org/IMG/pdf/dhor_resultats_du_recensement_de_l_horticulture_dans_les_niayes.pdf

Montginoul, M., & Rinaudo, J.-D. (2009). Quels instruments pour gérer les prélèvements individuels en eau souterraine ? Le cas du Roussillon. Économie Rurale, 310(Mars-avril), 40–56. https://doi.org/10.4000/economierurale.2149

Msangi, S., & Cline, S. A. (2016). Improving Groundwater Management for Indian Agriculture: Assessing Tradeoffs Across Policy Instruments. Water Economics and Policy, 02(03), 1650027. https://doi.org/10.1142/S2382624X16500272

Ndong, J.-B. (1995). L’évolution de la pluviométrie au Sénégal et les incidences de la sécheresse récente sur l’environnement / The evolution of rainfall in Senegal and the consequences of the recent drought on the environment. Revue de Géographie de Lyon, 70(3), 193–198. https://doi.org/10.3406/geoca.1995.4212

Nyenje, P. M., & Batelaan, O. (2009). Estimating the effects of climate change on groundwater recharge and baseflow in the upper Ssezibwa catchment, Uganda. Hydrological Sciences Journal, 54(4), 713–726. https://doi.org/10.1623/hysj.54.4.713

OECD. (2015). Drying Wells, Rising Stakes. OECD Publishing. https://doi.org/10.1787/9789264238701-en

Ostrom, E. (1990). Governing the commons : the evolution of institutions for collective action. Cambridge University Press.

Paris, Q. (1992). The von Liebig Hypothesis. American Journal of Agricultural Economics, 74(4), 1019. https://doi.org/10.2307/1243200

IFPRI, (2013). West African agriculture and climate change A comprehensive analysis. https://doi.org/10.2499/9780896292048

Robinson, S., Willenbockel, D., & Strzepek, K. (2012). A Dynamic General Equilibrium Analysis of Adaptation to Climate Change in Ethiopia. Review of Development Economics, 16(3), 489–502. https://doi.org/10.1111/j.1467-9361.2012.00676.x

Rosenzweig, C., Iglesias, A., Fischer, G., Liu, Y., Baethgen, W., & Jones, J. W. (1999). Wheat yield functions for analysis of land-use change in China. Environmental Modeling and Assessment, 4(2/3), 115–132. https://doi.org/10.1023/A:1019008116251

Roudier, P. (2012). Climat et agriculture en Afrique de l’Ouest : Quantification de l’impact du changement climatique sur les rendements et évaluation de l’utilité des prévisions saisonnières, chap.2. Ecole des Hautes Etudes en Sciences Sociales (EHESS). Retrieved from https://tel.archives-ouvertes.fr/tel-00874724/document

Roudier, P., Muller, B., Aquino, P., Roncoli, C., Soumaré, M. A., Batté, L., & Sultan, B. (2014). Climate Risk Management The role of climate forecasts in smallholder agriculture : Lessons from participatory research in two communities in Senegal. Climate Risk Management, 2, 42–55. https://doi.org/10.1016/j.crm.2014.02.001

Roudier, P., Sultan, B., Quirion, P., & Berg, A. (2011). The impact of future climate change on West African crop yields: What does the recent literature say? Global Environmental Change, 21(3), 1073–1083. https://doi.org/https://doi.ord/10.1016/j.gloenvcha.2011.04.007

Safouane, M., Saida, N., Sihem, J., & Mohamed, S. (2016). Using the Markov Chain for the Generation of Monthly Rainfall Series in a Semi-Arid Zone. Open Journal of Modern Hydrology, 06(02), 51–65. https://doi.org/10.4236/ojmh.2016.62006

Sekhri, S. (2013). Missing Water: Agricultural Stress and Adaptation Strategies in Response to Groundwater Depletion in India. Virginia Economics Online Papers. Retrieved from https://ideas.repec.org/p/vir/virpap/406.html

Sekhri, S. (2014). Wells, Water, and Welfare: The Impact of Access to Groundwater on Rural Poverty and Conflict. American Economic Journal: Applied Economics, 6(3), 76–102. https://doi.org/10.1257/app.6.3.76

Sene, I. M., Diop, M., & Dieng, A. (2006). Impacts of climate change on the revenues and adaptation of farmers in Senegal. CEEPA Discussion Paper, (Special series on Climate Change and Agriculture in Africa).

Smit, B., Pilifosova, O., & Patwardhan, A. (2001). Adaptation to Climate Change in the Context of Sustainable Development and Equity. Retrieved from https://www.ipcc.ch/ipccreports/tar/wg2/pdf/wg2TARchap18.pdf

Sultan, B., & Gaetani, M. (2016). Agriculture in West Africa in the Twenty-First Century : Climate Change and Impacts Scenarios , and Potential for Adaptation, 7(August), 1–20. https://doi.org/10.3389/fpls.2016.01262 Tanaka, S. K., Zhu, T., Lund, J. R., Howitt, R. E., Jenkins,

M. W., Pulido, M. A., … Ferreira, I. C. (2006). Climate Warming and Water Management Adaptation for California. Climatic Change, 76(3–4), 361–387. https://doi.org/10.1007/s10584-006-9079-5

Taylor, R. G., Koussis, A. D., & Tindimugaya, C. (2009). Groundwater and climate in Africa—a review. Hydrological Sciences Journal, 54(4), 655–664. https://doi.org/10.1623/hysj.54.4.655

Tine, A. K. (2004). Etude des transferts d’eau et problématique des nitrates dans la zone non saturée en région sahélienne. Exemples: nord et centre du Sénégal. Université Cheikh Anta Diop de Dakar.

Tomini, A. (2014). Is the Gisser and Sánchez model too simple to discuss the economic relevance of groundwater management? Water Resources and Economics, 6, 18–29. https://doi.org/10.1016/J.WRE.2014.05.004

Varela-Ortega, C., Blanco-Gutiérrez, I., Esteve, P., Bharwani, S., Fronzek, S., & Downing, T. E. (2016). How can irrigated agriculture adapt to climate change? Insights from the Guadiana Basin in Spain. Regional Environmental Change, 16(1), 59–70. https://doi.org/10.1007/s10113-014-0720-y

Wang, C., & Segarra, E. (2011). The Economics of Commonly Owned Groundwater When User Demand Is Perfectly Inelastic. Journal of Agricultural and Resource Economics, 36(1), 95–120. Retrieved from https://ageconsearch.umn.edu/record/105533/files/JARE_Apr2011__07_pp95-120_Wang.pdf?version=1

World Bank. (2014). Situation économique du Sénégal--Apprendre du passé pour un avenir meilleur. Retrieved from http://www.au-senegal.com/IMG/pdf/situation_economique_du_senegal2014.pdf